TerraLiner:12 m Globally Mobile Beach House/Class-A Crossover w 6x6 Hybrid Drivetrain

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



I. Turbines and Multi-Fuel Capability


**************************************



However, with all that said, again I cannot thank you enough dwh, for broaching the topic of microturbines. They have some distinct advantages that make them worthy of serious consideration as range-extenders in hybrid expedition motorhomes.

In popular imagination, jets used in automotive applications conjure up images of cars trying to break the sound-barrier in the desert – see http://en.wikipedia.org/wiki/Jet_car . But at a more mundane level, turbine engines have long been used in boats, locomotives, and tanks, and it's worth asking why. See http://en.wikipedia.org/wiki/Gas_turbine , http://en.wikipedia.org/wiki/Gas_turbine#Marine_applications , http://en.wikipedia.org/wiki/Gas_turbine-electric_locomotive , and http://en.wikipedia.org/wiki/Gas_turbine#Tanks .

To begin with, in terms of power-to-weight performance, turbines outclass conventional diesel engines: they are lighter and smaller than equivalent horsepower diesels. Which is why the U.S. Navy ships, for instance, tend to be powered by gas-turbines – see http://www.geaviation.com/marine/engines/military/lm2500/ . But it's not just lighter weight that makes turbines attractive. They are also attractive because they can be multi-fuel.

Multi-fuel capability matters to overlanders in particular, because by definition, an overlander is someone who takes a vehicle on a journey across multiple countries, multiple continents, and multiple "fuel regimes", i.e. regions where certain kinds and qualities of fuel tend to predominate. Whenever RTW expedition vehicles are discussed on ExPo, the problem of fuel quality comes up again and again. And so too in this thread. Fuel quality is increasingly troublesome, because new trucks sold in the First World will have the latest engines designed to cut down on emissions, engines that use ultra-low-sulphur diesel (ULSD) not yet widely available in the Third World -- see http://en.wikipedia.org/wiki/Ultra-low-sulfur_diesel . If one frequently uses high-sulfur diesel in a brand-new Euro VI engine, one will probably damage the engine -- see http://www.trucknetuk.com/phpBB/view...p?f=4&t=105341 and http://www.diyforums.net/high-sulphur-diesel-in-new-model-car-440378.html .

Apparently in Third World countries where only high-sulfur diesel is available, new imported ULSD engines are sometimes fitted with Hydrogen kits to solve the problem -- http://www.greencarcongress.com/2005/11/hydrogenenhance.html , http://archive.wired.com/cars/energy/news/2005/11/69529 , http://www.marzindustries.com/index.html , http://www.hydrogen-generators-usa.com/hydrogen-generator.html , http://www.hhomart.com/category.php?id_category=2 , and http://hydroxsystems.co.uk/hho-hydr...-cell-generator-cars-vans-hydrox-systems.html . But Hydrogen Fuel Enhancement is controversial, and the claimed benefits of adding Hydrogen to improve milage, and/or resolve fuel-engine incompatibility, should probably be met with some skepticism -- see http://www.popularmechanics.com/cars/alternative-fuel/gas-mileage/4310717 , http://www.popularmechanics.com/cars/alternative-fuel/gas-mileage/4310717-2 , http://www.popularmechanics.com/cars/alternative-fuel/gas-mileage/4271579 , and http://www.popularmechanics.com/cars/alternative-fuel/gas-mileage/1802932 . The real irony here is that supposedly "clean ULSD diesel" is not that clean -- see http://www.hybridcars.com/will-america-avoid-europes-clean-diesel-problems/ .

Now a hybrid expedition vehicle equipped with a microturbine range-extender could potentially cut through this gordian knot, enabling an overlander to fill up with just about any fuel available, anywhere. An overlander driving a vehicle equipped with microturbines could fill up with low-moisure
JP-5 or AN-8 when traveling in the coldest parts of Canada, Alaska, or Siberia. Then switch to local low-quality diesel when traversing the Altiplano in Bolivia. Elsewhere, such a vehicle could go "green", filling up with Biodiesel. In effect, microturbines would give such a hybrid vehicle the fuel-flexibility of an M1A2 Abrams' tank, whose AGT1500 turboshaft is designed to run on just about any type of fuel.


**************************************


J. Automotive Turbine: the precedent of the M1A1 Abrams Tank


**************************************



The
M1A2 Abrams is without a doubt the most famous automotive application of turbine technology – see http://en.wikipedia.org/wiki/Gas_turbine#Tanks , http://en.wikipedia.org/wiki/M1_Abrams , http://www.fprado.com/armorsite/abrams.htm , http://science.howstuffworks.com/m1-tank2.htm , http://www.military-today.com/tanks/m1a1_abrams.htm , http://www.army-guide.com/eng/product1780.html , http://www.army.gov.au/Our-work/Equipment-and-clothing/Vehicles/M1-Abrams-tank , http://www.militaryfactory.com/armor/detail.asp?armor_id=1 , and http://defense.about.com/od/weaponry/ss/Abrams-M1-Tank.htm#step-heading .

Many suggest that the Abrams was designed around its unique engine, and at present the Abrams is the only mass-produced turbine-powered land vehicle in the world. For that reason alone, the Abrams seems worth discussing a bit, given that the current sub-topic of the thread is microturbines.

There is a particularly good description of the Abrams AGT1500 turboshaft engine at http://cset.mnsu.edu/engagethermo/systems_tank.html . The AGT1500, made by Honeywell, is a modified version of the turbine originally used to power the Cobra helicopter; it produces 1500 HP, and has an exhaust temperature of 1100 Fahrenheit. For more information, see http://en.wikipedia.org/wiki/Honeywell_AGT1500 , http://aerospace.honeywell.com/defense/platforms/m1-abrams-tank , http://www.honeywell.com/sites/serv...t?docid=DBFF4ECEE-AF8F-8ABE-F6D2-0E2E8F6A88FB , http://www51.honeywell.com/aero/com...SurfaceSystems/AGT1500_Turbine_Technology.pdf , http://turbotrain.net/en/m1tank.htm , http://wryedge.com/portfolio/agt1500-engine/ , http://www.turbokart.com/about_agt1500.htm , http://www.turbokart.com/gasturbine.htm , http://www.aoi.com.eg/aoieng/military/overhaul/overhaul.html , and http://transupport.com .

Here are some images:

Abrams-tank.jpg Untitled-1.jpg AGT1500-2.jpg
Untitled2.jpg 22.jpg Untitled5.jpg
Untitled3.jpg m1-abrams-tank-power-pack.jpg


The first video below includes lots of descriptive visualizations of the AGT1500, while the second is an animated cutaway from Honeywell, indicating where the turbine sits in the Abrams tank:


[video=youtube;7Zc8dVGqTUI]https://www.youtube.com/watch?v=7Zc8dVGqTUI  [/video]



**************************************


J. Abrams Air-Intake/Exhaust


**************************************



It's important to remember that the turboshaft engine is just the "core" of the Abrams' power pack, which is much larger, and includes massive fans for sucking in air:


Untitled-1.jpg


Furthermore, as near as I can tell, the Honeywell video is not very accurate, because it shows the turbine mounted transversally. Whereas almost all other imagery on the web, both video and still, suggests that the Abrams turbine is mounted lengthwise, as per this very useful cutaway drawing:


abrams_main_battle_tank.f.jpg



Here are two videos of the Abrams having its powerpack pulled, which suggest the same:


[video=youtube;Sw0R_jAKGrE]https://www.youtube.com/watch?v=Sw0R_jAKGrE [/video]

**************************************

CONTINUED IN NEXT POST
.
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



Here are some more images of the complete Abrams power pack, being lifted into/out of tanks:


M1_Pack_2.jpg M1A1_engine_02.jpg 20060604075359_5hitmech3-20060604.jpg
USMCpullingM1.jpg USMCM1A1.jpg AGT1500_engine_and_M1_tank.jpg
M1A1_02.jpg M1A1_engine_00.jpg


See http://www.defense.gov/news/newsarticle.aspx?id=16138 , http://www.conceptart.org/forums/showthread.php/266984-Big-Tank?p=3666485 , http://www.armyproperty.com/Equipment-Info/M7-FRS.htm , http://www.overclock.net/t/1066226/engadget-man-builds-turbine-powered-batmobile-video/20 , http://www.tardec.info/GVSETNews/article.cfm?iID=0604&aid=06 , http://www.inetres.com/gp/military/cv/tank/M1.html , http://www.motortrend.com/classic/roadtests/8204_first_test_m1_abrams/photo_06.html , and http://www.alu.army.mil/alog/issues/JanFeb06/reset_armyeq.html .

What all these images seem to suggest is that the Abrams has two massive air-intakes located at the rear of the vehicle, equipped with big fans that suck in air to feed the turbine. The turbine then expels the exhaust via a third opening, located between the two air intakes:


Untitled-1.jpg Untitled-2.jpg


But I might be reading the engineering and the geometry wrong. If anyone reading this knows exactly how the turbine air-intake/exhaust in the Abrams works, please post!


**************************************

CONTINUED IN NEXT POST
..
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



Assume for a moment that the geometry described above is right. Locating the air-intakes for a massive turbine at the back of a tank makes sense, if only because this is the part of the vehicle that would be least exposed to enemy fire during battle. It's not exactly the "cleanest" place to locate air-intakes, but the Abrams uses nano-particle air-filters:


Abrams_at_speed_in_dust (caption).jpg

See http://www.donaldson.com/en/index.html , https://www.donaldson.com/en/aircraft/support/datalibrary/035251.pdf , http://www.donaldson.com/en/aircraft/support/datalibrary/itemsgeneral/071728.pdf , http://www.army-technology.com/contractors/hydraulics/donaldson/ , http://www.allfilters.net , http://autoengineer.wordpress.com/2006/09/24/is-nanofiber-filtration-really-that-big-a-deal/ , and http://www.ultimatesyntheticoil.com/Filters/Ea_Nanofiber_air_filters.htm . Although the AGT1500 turbine is relatively maintenance-free, the air-filters are not, and they have to be changed about once a week.

Now clearly, the big fans at the back sucking in air for the Abrams' turbine are a somewhat unique requirement. If the Abrams were not a tank, and if protection from enemy threats were not such a paramount consideration, then the air-intakes could have been mounted on the sides, on the top, or at the front of the vehicle.

Returning to microturbines: even though a microturbine would be much smaller than the Honeywell AGT1500 in the Abrams, it would still need to suck in lots of air to run. And two microturbines, for redundancy, would need to suck that much more air. Which is perhaps another reason why COE mounting makes the most sense: because mounted up front, with air-intakes facing forwards, the forward motion of the vehicle would force-feed air into the microturbines. But just like the air-intakes on the Abrams, the air-intakes of an expedition vehicle probably need to be equipped with nano-particle air-filters.

There is one thing that still puzzles me about the Abrams: what is its fording capability? This is described as 1.2 m without kit, and up to 2.37 m with a special "Deep Water Fording Kit", a kit that provides engine intake and exhaust towers -- see http://www.inetres.com/gp/military/cv/tank/M1.html , http://fas.org/man/dod-101/sys/land/m1.htm , http://www.russianscalemodels.com/viewmodel.php?id=837 , and http://www.network54.com/Forum/47209/thread/1322885596/Dragon+M1A1+AIM+as+an+USMC+vehicle- :


35080_6.jpg US_Navy_031214-N-3236B-008_A_Marine_from_the_13th_Marine_Expeditionary_Unit_(13th_MEU)_Tank_Plat.jpg abrams-fording.jpg

[video=youtube;Eko1rxeoybA]https://www.youtube.com/watch?v=Eko1rxeoybA [/video]


The big tower in back makes sense, that's for the exhaust. But the two towers on the side give pause for thought: is this where the AGT1500 turbine's air-intake is located instead? Or is it merely an alternative, secondary engine air-intake location for deep fording? Or perhaps for cabin venting? If anyone reading this knows the answer, again, please post.

In any case, these towers suggest that a microturbine-equipped expedition vehicle should in principle be just as capable of deep water fording, as a vehicle equipped with an ICE. The air-intake and exhaust just need to be thought through properly.


**************************************


K. Abrams Noise Level


**************************************



The M1A2 Abrams is often described as reasonably silent, at least in comparison to Germany's Leopard Tank – see http://en.wikipedia.org/wiki/Leopard_2 . Some claim that you can hear a "Leo" coming 30 or 40 minutes before you see it:




The Leopard 2 is propelled by the MTU MB 873 diesel engine, which generates approximately 1500 HP, similar to the turbine in the Abrams – see http://en.wikipedia.org/wiki/Leopard_2 , http://www.mtu-online.com/mtu/produ...-armored-vehicles/engines-for-heavy-vehicles/ , http://www.mtu-online.com/mtu/produ...t/985/cHash/f9d93ae76762f7411dc3ec5d39d99fd5/ , http://www.mtu-online.com/mtu/produ...t/986/cHash/25be4b9c2dca499367034a8c4bda201f/ , http://www.army-guide.com/eng/product150.html , and http://www.army-guide.com/eng/product1486.html .

The following are good videos that demonstrate how the Abrams turbine sounds:


[video=youtube;2ZfVP19mDm4]https://www.youtube.com/watch?v=2ZfVP19mDm4 [/video] [video=youtube;TCXwgPZXScM]https://www.youtube.com/watch?v=TCXwgPZXScM [/video] [video=youtube;sXE4tMEYCoI]http://www.youtube.com/watch?v=sXE4tMEYCoI [/video]


This is a video that demonstrates the turbine's noise as heard inside the tank:




And these videos demonstrate the turbine's noise when running outside the tank:




Also see https://www.youtube.com/watch?v=Gn8V0VKsxfw and https://www.youtube.com/watch?v=pSB9kBC87T8 .

In short, the Abrams may be quieter than a Leo, but its not exactly silent either. Otherwise the U.S. military would not be spending money on fuel-cell research, which promises to deliver a true “stealth tank" – see http://www.dailytech.com/US+Military+Goes+Green+Testing+Fuel+Cell+M1+Abrams+Tanks/article19022.htm . The article just referenced suggests that the Abrams can be heard many miles away, too.

.
**************************************

CONTINUED IN NEXT POST
..
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



L. The Multi-Fuel Capability of the Abrams AGT1500 Turbine, and Low Maintenance


**************************************


As suggested at the outset, it's the multi-fuel capability of the AGT1500 turbine that really sets it apart. Sure, the Abrams' direct-drive turbine is not exactly fuel efficient: it typically gets less than 1 mile to the gallon -- see http://www.answers.com/Q/What_is_the_mpg_of_a_abrams_tank . The Abrams carries a huge 500 gallon fuel tank, giving it a maximum range of approximately 265 - 290 miles. But the Abrams can guzzle the cheap stuff coming out of the refining process, like kerosene, as opposed to highly refined gasoline. You could probably run an Abrams on Russian vodka or nail polish. A reliable website describes the Abrams' multi-fuel capability as follows:


The AGT 1500 turbine engine has five primary fuels: diesel fuels 1, 2, and arctic grade, and jet propellant fuels 4 and 5. In case of an emergency, the engine is also capable of using combat gasoline and marine diesel.
See http://cset.mnsu.edu/engagethermo/systems_tank.html . Multi-fuel capability gives the Abrams a distinct tactical advantage:

The turbine in the Abrams can run on diesel, gas, kerosene, JP 1,2,3,4, alcohol, furnace fuel, just about any distillate of oil but not crude oil or bunker fuel except in areas were it is hot 24 hours a day.

This means that Tank units can take any fuel source captured on the battle field and use it for their own units, something that they learned in WW2 would be a major advantage.
See http://www.quora.com/What-advantage...her-than-diesel-engines-like-most-other-tanks . Clearly, such multi-fuel capability would also prove a tremendous advantage for expedition motorhomes travelling in Third World countries, where fuel is often very dirty and low-grade.

Another important consideration for the U.S. military was that a turbine would have fewer moving parts. Less to go wrong, and less maintenance:

“Unlike a diesel, which has to be serviced as a whole engine, the AGT1500 can be easily separated and serviced in the field, keeping more vehicles operating. With the AGT1500’s Digital Electronic Control Unit (DECU), you get operational diagnostic capability which results in 30 % less maintenance time and 20 % lower idle fuel consumption.

Contrast these features with a diesel engine which is noisy, smoky, requires a cooling system (space and power loss), a heater, a warm-up period, and has more moving parts to wear out. Quite simply, there’s no comparison.”
See http://www.honeywell.com/sites/serv...t?docid=DBFF4ECEE-AF8F-8ABE-F6D2-0E2E8F6A88FB . The literature produced by Capstone and Bladon emphasizes the same, low-mainteneance virtue of turbines -- see http://www.cogeneration.org/111011Conf/Presentations/McAvoy.pdf , http://www.ibtgroup.it/download/pdf/en/Capstone Overview.pdf , http://www.capstoneturbine.com/company/faq.asp , http://www.capstoneturbine.com/news/testimonials.asp , http://www.capstoneturbine.com/company/valueofcapstone.asp , http://www.bladonjets.com/products/micro-gensets/ , http://www.bladonjets.com/products/micro-air-bearings/ , and http://www.bladonjets.com/technology/gas-turbines/ .

So the M1A2 Abrams sacrifices fuel-efficiency in favor of:

(1) performance: turbines have a much better power-to-weight ratio than ICE diesels
(2) multi-fuel capability
(3) comparative silence and stealth
(4) reliability
(5) ease of maintenance

Not a bad tradeoff. However, as an additional negative, turbines “idle” at about ¾ full power. So the latest M1A2 variants have “ an upgraded APU for stationary operations (to keep NBC air conditioning, electronics, etc. operating)” – see http://www.quora.com/What-advantage...her-than-diesel-engines-like-most-other-tanks .


**************************************


M. The Future of the Abrams Powerpack


**************************************


Over the last 15 years there has been some work towards developing a replacement for the AGT-1500, called the LV 100-5 gas turbine – see http://cset.mnsu.edu/engagethermo/systems_tank.html , http://www.geaviation.com/press/military/military_20010827.html , and http://calhoun.nps.edu/handle/10945/6043 . But apparently it has not yet been implemented. Instead, Honeywell has been maintaining and upgrading AGT-1500 engines under the “Tiger” program – see http://www.nationaldefensemagazine.org/archive/2006/September/Pages/Overhaul2874.aspx , http://www.defenseindustrydaily.com...rams-us-army-puts-a-tiger-in-its-tanks-01790/ ,
http://www.army.mil/article/14494/1000th-tiger-engine-completed-at-anniston/ , https://www.youtube.com/watch?v=xG5XOCrAnpI , http://forums.spacebattles.com/threads/us-army-to-review-m1-abram-engine-upgrades.280223/ , and http://forum.worldoftanks.com/index.php?/topic/238473-lv-100-5-turbine-engine/ . And as suggested above, before the new LV 100-5 turbine is implemented, it is quite possible that the Abrams' powerpack might be replaced by a hybrid or fuel-cell alternative.

It's important to realize that the Abrams has a completely modular design, which means that any given tank can be easily modified or upgraded. The U.S. military has taken this idea to an extreme, and has not built a completely new Abrams M1 tank from scratch since 1993. Instead, all "new" Abrams M1 tanks since then have been rebuilt from reconstituted old tanks -- see http://channel.nationalgeographic.com/channel/ultimate-factories/videos/abrams-tank/ :


[video=youtube;G8uFVKmAj5o]https://www.youtube.com/watch?v=G8uFVKmAj5o [/video]

Here is a good documentary about the Abrams, followed by a much shorter history. The latter video includes discussion of the controversy that plagued the Abrams during the 1980's, whereas the longer documentary is almost exclusively laudatory, and contains virtually no criticism:


[video=youtube;OFN79wuuTy8]https://www.youtube.com/watch?v=OFN79wuuTy8 [/video] [video=youtube;97lBxGPppW0]https://www.youtube.com/watch?v=97lBxGPppW0 [/video]
[video=youtube;ZlGt7m1392g]https://www.youtube.com/watch?v=ZlGt7m1392g [/video] [video=youtube;nF_HQFmHpg8]https://www.youtube.com/watch?v=nF_HQFmHpg8 [/video]
[video=youtube;l0uWcFpCi28]https://www.youtube.com/watch?v=l0uWcFpCi28 [/video]

And for some Youtube playlists at https://www.youtube.com/playlist?list=PL30AE97AB7267E17C and https://www.youtube.com/playlist?list=PL81C433794B9CE823 .

One final note: the Abrams’ 120 mm gun was made by Rheinmetall-MAN Defence, the same company that now makes the SX and HX series trucks discussed at length in this thread. More recently production of the gun for the Abrams tank specifically has been moved to the United States, where it is manufactured under license. Germany's Leopard 2 tank uses the same gun -- see http://en.wikipedia.org/wiki/Rheinmetall_120_mm_gun , http://www.rheinmetall-defence.com/...mmunition/direct_fire/large_calibre/index.php , and http://www.dtic.mil/ndia/2008gun_missile/6526Huls.pdf :


[video=youtube;1V0v4VwgFFQ]https://www.youtube.com/watch?v=1V0v4VwgFFQ&index=52&list=PL81C433794B9CE8 23[/video]



**************************************

CONTINUED IN NEXT POST
..
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



4.
Serial Hybrid or "REEV" preferred over Parallel Hybrid



***************************************


I devoted so much energy to researching and writing about turbines and microturbines in this thread, because over the next 20 years this particular form of hybrid solution seems the most promising for a large, 6x6, RTW (Round the World) expedition motorhome.

As the various Wikipedia articles about "hybrid vehicles" make clear, there now exists a bewildering variety of technological possibilities -- see http://en.wikipedia.org/wiki/Hybrid_vehicle , http://en.wikipedia.org/wiki/Hybrid_vehicle#Hybrid_electric-petroleum_vehicles , http://en.wikipedia.org/wiki/Hybrid_electric_vehicle , http://en.wikipedia.org/wiki/Hybrid_electric_vehicle#Military_vehicles , http://en.wikipedia.org/wiki/Hybrid_vehicle_drivetrain , http://en.wikipedia.org/wiki/Hybrid_electric_bus , and http://en.wikipedia.org/wiki/Hybrid_electric_vehicles_in_the_United_States . So much so, that the term "hybrid vehicle" is nearly useless. The term "hybrid" is much too broad, and applies to power trains that are not even remotely similar, other than the fact that they are somehow "mixed" solutions.

To cut through the confusion, I would like to suggest a few propositions:

A. Eventually batteries, fuel cells, or both, will become good enough and cheap enough to make possible all-electric vehicles that have long driving ranges. But this is still at least 20 years into the future.

B. However, because the automotive design and engineering community is constantly pushing technology towards the "all electric" end-goal, the most promising interim technologies will be those that serve as stepping stones towards this goal, in addition to having merits in their own right.

C. So the most promising interim technologies will be "series hybrids" or "REEVs": range extended electric vehicles, vehicles that are almost "all electric", but that still have fuel-fired generators to recharge the batteries.

Here is a quote from an article that clearly articulates this rationale:

The advantages of a series hybrid car are huge. They are far, far less complex than conventional hybrid cars, because only the electric motor, with its huge range of usable RPM, is connected to the drivetrain. Another huge advantage is that series hybrid cars have their second motor, a small, ultra-low-emission gas or diesel engine, connected to a generator to recharge the battery pack while the car is being driven. By doing this, a cheaper and more reliable battery pack can be used, and there is no need for a complex heat management system that is still necessary for the lithium ion batteries.
It is well and good to criticize General Motors for discontinuing the EV-1. But they are back with another green car which is as ahead of its time as the EV-1 once was, and this car is going to attract a much bigger market.

Critics may claim the EV-1 was a zero-emission vehicle, while a series hybrid car has a small, ultra-low emission onboard motor, and therefore it isn’t as green as the EV-1, or the Tesla Roadster, or any 100% battery powered car. Someday, when all electricity generated everywhere is done so with no combustion or other form of environmental degradation, this concern may be valid, but until that time, this is pure poppycock.


See http://www.ecoworld.com/other/serial-hybrids-are-here.html , and also see http://www.ecogeek.org/content/view/1298/ .

Here is a schematic that nicely illustrates the basic REEV concept:


Untitled-1.jpg

And here is another that illustrates the "parallel hybrid" concept, in which an ICE also drives the wheels directly:


Untitled-2.jpg


Of course, in a more typical parallel hybrid the ICE will also power a generator that feeds the batteries which drive the electric motors:


Untitled-3.jpg


But still, on my own view the REEV concept is preferred to parallel hybrid, especially for an expedition motorhome. Although egn admitted that he did not know which hybrid concept "is best suited for an off-road overlander", he had some interesting things to say about the advantages when only electric motors directly drive the wheels, and not the fuel-fired engine:

The trend goes towards hybrid and electric vehicles, not only because this is more fuel efficient and has lower emissions. It has also large advantages regarding power and torque, which is very important off-road. With an hybrid driveline it is possible to distribute all the components of engine/transmission all over the vehicle and most smaller components can be placed without much additional space.

You cannot provide the power to move a heavy vehicle with the power provided by alternators. And the point is, that you don't need as much power for the fuel engine with a hybrid vehicle, because part or all of the power can come from much more powerful electric motors, buffered by the battery. The fuel engine/generator must only provide the average power and not the peak power necessary going up a hill or through off-road terrain. The peak power comes from the electrical motors, which take stored energy in the battery.

Which on is best suited for an off-road overlander, I really don't know. The above engine/generator unit can be used for a serial hybrid drive train. But another possibility I can think of is a parallel-hybrid, where the fuel engine directly drives one axle and the other axles are powered by electrical motor. This can save an extra generator because you can use the electrical motors for the other axles as generator, when part of the fuel engine power is not used. But then you cannot charge battery when the vehicle doesn't move. And you loose redundancy.

I have some additional reasons for preferring REEV or "serial hybrid". But it would be interesting to hear from someone who thinks the opposite; who thinks that a parallel hybrid vehicle is preferred.


***************************************


5. Bi-Fuel, Flexible-Fuel, versus True Multi-fuel REEV Capability


***************************************


Assuming the above reasoning is correct, the only question then is: "What kind of fuel-fired engine should be used as a range-extender, to drive an electric generator?" The default assumption is usually some kind of ICE, because ICE-driven electric generators are so ubiquitous.

But for an overlanding vehicle specifically, the prior question should be, "What kind of engine is the most multi-fuel capable?"

Now to be sure, bi-fuel or flexible-fuel ICE-driven vehicles have existed for decades -- see http://en.wikipedia.org/wiki/Bi-fuel_vehicle , http://en.wikipedia.org/wiki/Flexible-fuel_vehicle , and http://en.wikipedia.org/wiki/Multifuel . In Italy it seems that every second vehicle is bi-fuel, running on CNG as well as diesel. While in Brazil, the majority of new vehicles run on a combination of gasoline and ethanol -- see http://en.wikipedia.org/wiki/Flexible-fuel_vehicles_in_Brazil , http://en.wikipedia.org/wiki/Ethanol_fuel_in_Brazil , and http://en.wikipedia.org/wiki/History_of_ethanol_fuel_in_Brazil . Multi-fuel ICE gensets also exist -- see http://www.generac.com/for-business/business-standby-products/bifuel-generators and http://www.wolterps.com/pubs/tech_perspective/670-0207_Generac_March_mailer.pdf .

But a RTW, globally capable expedition vehicle needs a range-extending engine that is not tailored to the fuels widely available in a particular country, for instance, the widespread availability of CNG at gas stations in Italy. Rather, what's wanted is a an engine that can burn both high-grade Jet Fuel at one end, low-grade diesel or even kerosene at the other, and everything else in between, including ULSD (ultra-low-sulfer diesel). See http://en.wikipedia.org/wiki/Jet_fuel , http://en.wikipedia.org/wiki/Kerosene , http://en.wikipedia.org/wiki/Diesel_fuel , http://en.wikipedia.org/wiki/Ultra-low_sulfur_diesel , and http://en.wikipedia.org/wiki/Multifuel .

And as far as I know, the only currently available type of engine that truly fits this description is a turbine, be it a very large turbine like the AGT1500, or a much smaller microturbine like the Capstone C30 or C65.



***************************************


6. The Multi-fuel LDT-465, in the M35 "Deuce and a half"


***************************************


It's worth noting, however, that the long-lived M35 2 1/2 ton medium-sized cargo truck used by the American military also had a multi-fuel engine, even though it was an ICE -- see http://en.wikipedia.org/wiki/M35_2½-ton_cargo_truck , http://www.military-today.com/trucks/m35.htm , and http://olive-drab.com/od_mvg_www_deuce_m35.php . Here are some videos of the M35 or "Deuce and a half" in action:


[video=youtube;gitJG6ePgVQ]https://www.youtube.com/watch?v=gitJG6ePgVQ [/video] [video=youtube;EUT8rN-1zi0]https://www.youtube.com/watch?v=EUT8rN-1zi0 [/video]
[video=youtube;Aj30pWScdJg]https://www.youtube.com/watch?v=Aj30pWScdJg [/video]


Also see https://www.youtube.com/watch?v=YkwOioXLAyI and https://www.youtube.com/watch?v=6dt7W_U-KT8 , and for some YouTube M35 "Deuce and a half" playlists, see https://www.youtube.com/playlist?list=PL6CD18CFAD7028AC9 and https://www.youtube.com/playlist?list=PLt1nzcwjIAgu6aiYDacvItuPv4eyhi3LE .

The M35 no longer seems in production, having been replaced by the MTVR and FMTV series of trucks that were covered earlier in the thread -- see posts #330 - #332, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page33 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page34 (standard ExPo pagination) . And it does not seem that the MTVR and FMTV have equally multi-fuel-capable engines, although I could be wrong about this.

Although the M35's engine, the LDT-465, has been around for ages, it still seems available from Hercules Manufacturing -- see http://www.herculesengine.com/history.htm and http://www.herculesengine.com/military . Here are some YouTube videos that provide an idea of what this turbocharged, multi-fuel engine sounds like:


[video=youtube;nufRF1XEdAc]https://www.youtube.com/watch?v=nufRF1XEdAc [/video] [video=youtube;DcRAJYcYRQk]https://www.youtube.com/watch?v=DcRAJYcYRQk [/video]
[video=youtube;M_uVayq119A]https://www.youtube.com/watch?v=M_uVayq119A [/video]


Also see https://www.youtube.com/watch?v=U0CUUgaXfKg , https://www.youtube.com/watch?v=EWilbJvXtog , https://www.youtube.com/watch?v=SQXadRJxC0Y , and https://www.youtube.com/watch?v=qn_XMJ8KGKw . In the past Continental Motors and the White Motor Company also manufactured the LDT-465, but these companies seem to no longer exist -- see http://en.wikipedia.org/wiki/Continental_Motors_Company and http://en.wikipedia.org/wiki/White_Motor_Company .

Here are some discussion threads about the LDT-465: http://www.steelsoldiers.com/showthread.php?44802-How-does-the-multifuel-engine-actually-work , http://www.steelsoldiers.com/showth...T-465-in-terms-of-quot-multifuel-ability-quot , http://www.thedieselstop.com/forums/f33/continental-multifuel-ldt-465-1d-engine-woes-39654/ , and http://www.steelsoldiers.com/showth...-of-Continental-turbo-diesel-engines-in-M35A2 . And for an ExPo discussion thread about M35 camper conversions, see http://www.expeditionportal.com/forum/threads/129997-Red-s-deuce-camper-project and http://www.expeditionportal.com/forum/threads/127877-Military-Surplus-camper-vehicles .

If anyone reading this knows of other, roughly equivalent multi-fuel possibilities, turbine or ICE, please post!


***************************************


6. An RTW Motorhome that Can Handle Both High Altitude and Extreme Cold



***************************************


Why Jet fuel?

The answer in a nutshell: to handle extreme cold.

It's obvious enough that an RTW motorhome must be able to handle a variety of road conditions. As this thread developed, it became apparent that an RTW expedition vehicle does not need to be a "true off-road" motorhome, i.e. the kind based on a UniMog chassis. But an RTW does need to be a "bad-road" motorhome, a term I first heard used by Peter Thompson, to describe Mañana, his fully integrated expedition vehicle built on a MAN chassis -- see posts #212 and #214 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page22 .

Less obvious is that a truly globally capable expedition motorhome needs to be able to hand serious altitude. Not just 10,000 feet in Colorado or the Alps, but so too 13,500 feet in Bolivia, or 14,500 - 18,000 feet in Tibet.

In addition, a truly capable expedition motorhome needs to handle extreme cold. Some might not enjoy winter landscapes, but many of us do. So the ability to drive through Siberia, the Canadian Prairies, or central Alaska in the middle of winter seems an important design specification. And so too the ability to cross the Tibetan plateau in January, not just in June.

In Manitoba and Saskatchewan in the winter, overnight temperatures can get as low as −40 °C (−40 °F) on several days, and the temperature may remain below −18 °C (0 °F) for weeks. In Alberta, extreme winter minimum temperatures are possible as low as −54 °C (−65 °F) in northern Alberta, and −46 °C (−51 °F) in southern Alberta. See http://en.wikipedia.org/wiki/Western_Canada , http://en.wikipedia.org/wiki/Climate_of_Manitoba , http://en.wikipedia.org/wiki/Saskatchewan#Climate , and http://en.wikipedia.org/wiki/Alberta#Climate . Interior Alaska (e.g. Fairbanks) can get as cold as −60 °F (−51.1 °C), and Siberia averages −25 °C (−13 °F) in January. See http://en.wikipedia.org/wiki/Climate_of_Alaska and http://en.wikipedia.org/wiki/Siberia .

Now granted, because of climate change, the Tibetan Plateau is getting warmer -- see http://www.economist.com/news/scien...ird-largest-area-ice-about-undergo-systematic , http://www.theguardian.com/environm...limate-change-tibetan-plateau-audio-slideshow , and http://www.ft.com/cms/s/2/ee1f3f80-1029-11e3-a258-00144feabdc0.html#slide0 . But even so, winter temperatures on the Tibetan plateau also can also drop as low as −40 °C (−40 °F) -- see http://en.wikipedia.org/wiki/Tibetan_Plateau .

The Altiplano in Bolivia is closer to the equator than Tibet, not as high, and warmer, with summer temperatures ranging from 12 to 24°C , and winter temperatures from -20 to 10°C -- see http://en.wikipedia.org/wiki/Altiplano#Climatic_zones , http://en.wikipedia.org/wiki/Geography_of_Bolivia#Climate , and http://www.explorebolivia.com/our-country/map-of-bolivia/ .

Here are some maps of annual mean temperature, as well as some more specific winter climate maps. The first three usefully illustrate why Tibet is often described as a "Third Pole":


atl_avgwintemp_asi.jpg ... Annual_Average_Temperature_Map.jpg

capture_15.jpg ... janmeanna.jpg


This next set illustrates how the Altiplano and the Andes in general are colder than most of South America, but not nearly as cold as Tibet:


temp-jan.jpg ..... temp-july.jpg ..... atl_avganntemp_sam.jpg


See http://anthropology.ua.edu/blogs/ant475/category/adaptability/ , http://www.sage.wisc.edu/atlas/maps.php?datasetid=54&includerelatedlinks=1&dataset=54 , http://www.povertyeducation.org/geography-and-economic-growth.html , http://weatheradvance.com/2012/12/2...erifyi/640x480_currents_nam_temperature_i1-3/ , http://stephenliddell.co.uk/2013/12/04/lost-in-the-world-of-maps/ , http://www.movehub.com/blog/moving-abroad-checklist , http://faculty.smu.edu/bakewell/BAKEWELL/period.html , http://www.sage.wisc.edu/atlas/maps.php?datasetid=35&includerelatedlinks=1&dataset=35 , http://www.explorebolivia.com/our-country/map-of-bolivia/ , and http://www.globalsecurity.org/military/world/bolivia/maps.htm .

Yes, for many overlanders such extreme winter temperatures are a bit academic. And even in the case of a "Round the World" motorhome, one could organize things so that one spends summers closer to the poles, and winters closer to the equator.

But very cold places in the middle of winter covered with snow can be quite beautiful. Just a few years ago, for instance, I was in St. Petersburg, Russia, in the middle of winter, and the visit coincided with an unusual stretch of solid sunshine for 6 days. St. Petersburg is the "Paris of the North", and highly recommended in all seasons -- http://en.wikipedia.org/wiki/Saint_Petersburg . But there was something particularly compelling about the standard Russian-imperial color scheme for buildings (gold + blue), set against snow. Took some amazing photographs on that trip.

Fairly recently the Turtle expedition also crossed Siberia in the winter -- see http://turtleexpedition.com/vehicles/turtle-iv/ . And lots of expedition vehicles are designed to handle the same.


**************************************

CONTINUED IN NEXT POST
..
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST

**************************************



7. Learning from Antarctica



***************************************


Thinking about the temperature and alitude requirements of a RTW motorhome, then led me to start wondering (and posting) on the "High Altitude Heating" thread about vehicles used in Antarctica, and how they might be configured to handle both Antarctica's extreme cold, as well as Antarctica's high altitude. For further discussion, see posts #72 - #94 and #97 - #99 at http://www.expeditionportal.com/for...BEST-High-Altitude-Solution-for-Heating/page8 , http://www.expeditionportal.com/for...BEST-High-Altitude-Solution-for-Heating/page9 , andhttp://www.expeditionportal.com/for...EST-High-Altitude-Solution-for-Heating/page10 .

Since posting in the other thread I've been in touch with David Weimer, who has participated in a number of South Pole traverses which he documents beautifully on his blog, "Beyond the Backyard", at http://beyondthebackyard.com/category/polar-tractor-traversing/ and http://beyondthebackyard.com/2013/12/17/2013-2014-south-pole-traverse-day-41/ . David has kindly given me permission to repost his photographs on ExPo, and has already answered many of my questions about high-altitude/extreme-cold vehicles and heating. He is waiting to hear back from some of the traverse mechanics with more specific information about particular products. When I hear back from David again, I'll then post all the collected info in one go.

Here is a small sampler of Antarctic vehicles. For images of many more, see the "High Altitude Heating" thread:


072-copy.jpg 01abb-copy.jpg plateau1.jpg
nodwell4.jpg IMG_0367.jpg IMG_0315-snocat.jpg
sastrugi1.jpg antarctic3.jpg antarctic10.jpg
dsc_6215.jpg


Not all of these vehicles are designed to travel on Antarctica's high-altitude ice-plateau, but many of them are.

The South Pole's altitude is 2,835 m above sea-level, or 9,300 feet, and the East Antarctic Ice Sheet reaches a maximum altitude of 4,091 meters, or 13,421 feet, at "Dome A". But the altitude is actually more than that, from the point of view of lowered air pressure. Low temperatures in Antarctica mean that atmospheric pressure falls off more rapidly with altitude, and so the average air-pressure at Dome A corresponds to a “pressure-altitude” of 4,530 m, or 14,860 feet, for more temperate climates. See http://en.wikipedia.org/wiki/Dome_A , and see post #27 in the "High Altitude Heating" thread, at http://www.expeditionportal.com/for...BEST-High-Altitude-Solution-for-Heating/page3 , for further discussion of the implications for a gen-set.

So too, if you read some South-Pole blogs, they relate how the South-Pole station's pressure-alititude is really 10,000 - 11,000 feet -- see
http://https://southpoledoc.wordpres...tation/page/3/ . Indeed, the South Pole's true "pressure altitude" is so high, that altitude sickness presents a medical problem for recently arrived scientists who work there -- see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3114308/ . About 50 % of recent arrivals to the South Pole show signs of altitude sickness in the first few days; 20 % have persistent symptoms more than 3 days after arrival, and 2 % develop life-threatening symptoms. Prince Harry also suffered altitude sickness on his way to the South Pole, and he was not alone -- see http://www.today.com/news/prince-har...rek-2D79402025 , http://www.itv.com/news/2014-03-18/w...ole-challenge/ , http://www.dailymail.co.uk/news/arti...outh-Pole.html , and http://www.dailymail.co.uk/news/arti...ety-fears.html .

The Soviet Union's permanent "Vostok" station at the center of the East Antarctic ice sheet is located even higher, at
3,488 metres (11,444 ft) -- see http://en.wikipedia.org/wiki/Vostok_Station .

As for Antarctica's extreme-cold, it varies from region to region. Antarctica is a continent after all. Wikipedia provides the following useful summary:


The lowest reliably measured temperature of a continuously occupied station on Earth of −89.2 °C (−128.6 °F) was on 20 July 1983 at Vostok Station.[SUP][3][/SUP][SUP][4][/SUP] For comparison, this is 10.7 °C (19.3 °F) colder than sublimingdry ice (at sea level pressure). The altitude of the location is 3,900 meters (12,800 feet).

The lowest recorded temperature of any location on Earth surface was −93.2 °C (−135.8 °F) at
81.8°S 59.3°E, which is on an unnamed Antarctic plateau between Dome A and Dome F, on August 10, 2010. The temperature was deduced from radiance measured by theLandsat 8 satellite, and discovered during a National Snow and Ice Data Center review of stored data in December, 2013.[SUP][5][/SUP][SUP][6][/SUP]

The highest temperature ever recorded in Antarctica was 14.5°C (58.2°F) in two places,
Hope Bay and Vanda Station, on 5 January 1974.[SUP][7][/SUP] The mean annual temperature of the interior is −57°C (−70°F). The coast is warmer. Monthly means at McMurdo Station range from −26°C (−14.8°F) in August to −3°C (26.6°F) in January.[SUP][8][/SUP] At the South Pole, the highest temperature ever recorded was −12.3°C (9.9°F) on 25 December 2011.[SUP][9][/SUP] Along the Antarctic Peninsula, temperatures as high as 15°C (59°F) have been recorded,[SUP][clarification needed][/SUP] though the summer temperature is below 0°C (32°F) most of the time. Severe low temperatures vary with latitude, elevation, and distance from the ocean. East Antarctica is colder than West Antarctica because of its higher elevation.[SUP][citation needed][/SUP] The Antarctic Peninsula has the most moderate climate. Higher temperatures occur in January along the coast and average slightly below freezing.


See http://en.wikipedia.org/wiki/Climate_of_Antarctica, and also see http://www.coolantarctica.com/Antar...environment/climate_graph/climate_weather.htm .

So I began wondering how the ICE vehicles used in vehicles to cross the Antarctic plateau, and/or ferry supplies to the new South Pole station, manage to function in such extreme conditions. Rather conveniently, the combination of solutions that land vehicles use to cope with Antarctic conditions
are well-summarized in the Car & Driver article titled "Polar Motion: A Look Inside Driving in Antarctica" , at http://www.caranddriver.com/features/polar-motion-a-look-inside-driving-in-antarctica-feature . And one critical element in that combination is type of fuel.

The following is a lengthy quotation, because the article contains so much good, first-hand information:




How long do cars and trucks survive at the South Pole? What does it take to get around in a land where the sun sets in late April and doesn't rise again for months? Above all, is it any fun?


[Car & Driver interviews George Blaisdell, the USAP's operations manager]


McMurdo is the continent's primary logistics hub. What are the driving conditions like?

Well, we run three permanent stations on the continent, two of which are on bedrock. The average snow thickness is about 8000 feet, and just two percent of the continent's mass is exposed—everything else is covered by ice and snow. So almost all our vehicles are designed to operate off-road. There are some gravel roadways suitable for pickups with oversized tires, but they're the exception, not the rule.

For the rest of what happens at McMurdo and everything at the South Pole, vehicles have to be capable of operating at ground pressures of less than 20 psi—ideally less than 5 psi, which usually means big tundra tires like you see on oilfield rigs. We have a few improved trails on snow and ice, but a lot of what we drive on is completely untouched terrain. The snow there isn't like the powder that falls in Colorado—it's windblown, with really low moisture content, and quite hard. If you kick it with your boot, you're likely to hurt yourself.

Most of our vehicles are for moving materials or, to a lesser extent, personnel. We primarily move people by air, so we have a lot of vehicles for runway maintenance—large tractors on rubber tracks that tow large compactors or snow drags, that kind of thing. We move a lot of snow.

We have a [Foremost Terra Bus] that we use as an airport shuttle. It was originally built for the northern oil fields, with balloon tires seven feet in diameter and six feet across. We have customized, lifted 15-passenger vans running 40-inch bead-lock tires at 10 psi during the summer months when snow roads are at their weakest. The rest of the year they run at about 18 psi to reduce tire wear. We have 130 snowmobiles, 33 bulldozers, 52 tracked over-snow vehicles, 45 wheeled loaders, 30 rubber-tracked agricultural tractors (used for heavy over-snow towing), 28 heavy trucks, and 90 light trucks and vans…


What's the average life span of heavy equipment there? The cold and conditions have to take a toll.

Nearly everything lasts longer than you'd think. There are two reasons for that: First off, we work intensely with a lot of equipment during the summer, but it's all parked for the winter. At the South Pole, a really high temperature might be 60 or 70 below, or it might be 80 or 100 below. A bulldozer sees about three months of intense use, in two 12-hour shifts. Then it sits idle for nine months.

The second part is the exceedingly clean environment. There's no sea spray, no smog, no bizarre chemicals in the air, no dust to speak of. You can have a bulldozer pushing huge quantities of snow—the resistance and the density are so much less than soil—without tapping into the capability of the dozer. Our dozers have specially designed blades that are 70 percent larger than normal blades. We're still running two bulldozers built in 1956. They're long in the tooth, and we have to manufacture parts, but it's common for us to get 20 to 25 years out of a vehicle that the manufacturer would list at 12 to 15.


What about vans and big stuff like the Foremost Terra Bus? Same principle?

Pickups and vans wear out closer to normal. They get the most use of anything we have—our light-vehicle fleet sees 3500 miles per year and averages 4 mph. They're used pretty hard, the way you would expect a contractor to use a truck, and we replace them roughly every seven years. For the rest of our fleet, we range between 400 miles for our ambulance to 13,000 miles for our civil works foreman's truck. You can't get around the environment. Winds get pretty high, and open doors can get caught in the wind and bent. Big stuff
tends to move around in storms, garage doors and heavy things, and containers tip over and smash vehicles. There are times when everyone is contained indoors and the vehicles take a pounding.

The Foremost stuff was built for oilfield use in Canada and northern Alaska. There's still plenty of life left in those things. We've redone engines and such, but for the most part, it's plug and play—two long box beams for the chassis and giant Eaton axles hooked to it. It's a giant Lego [set].


So the vans are lifted, the oilfield vehicles are sturdy, and the production-based pickups are basically on the world's biggest, nastiest job site. Any Antarctic-specific modifications?

Well, we have extra heaters in a lot of things, for one. Permanent stations, where vehicles primarily hang out, get battery heaters, coolant heaters, transmission heaters, differential heaters. We have heavier vehicles that are drawing a kilowatt while plugged in because of the heating needs. For the bending doors, we use seatbelt material to create a strap from the door jamb to the door itself so they can't come close to the stops in high winds. Exhausts get covers to keep snow from blowing in. Heavy equipment gets custom air breathers and preheaters. We install manual parking-brake disconnects—there are manual locking valves in all the vehicle cabs—because it's far too easy for parking brakes to ice up and jam. Everything gets radios, obviously, as it all has to be prepped to survive on its own and let you call for help.


At those temperatures, fluids have to be a problem.

The light trucks and snowmobiles use Mogas, a military-grade, low-moisture gasoline; everything else runs on JP-5—similar to Jet A1—or AN-8, a unique kerosene with a low gel point of minus-53 degrees Fahrenheit. Every piece of equipment, from aircraft to generators to heavy equipment to snowmobiles and chain saws, operates on one of these three types of fuel.


Diesels aren't exactly the cleanest things out there, and that's a pretty sterile environment. Any plans to greenify the fleet?

We're working pretty hard to convert our vehicle fleet to electric power, at least where it makes sense. We already have two electric trucks down there—light vehicles built by
Minnesota's E-Ride Industries. You see them a lot on university campuses. Fuel is a commodity, and our V-8s spend a lot of time idling. As mid-size trucks start to show up with electric or hybrid powerplants, USAP will be paying close attention to their potential. For each unit of fuel we burn in our powerplant, we get back 33 percent of that fuel's energy as electricity. We use heat exchangers to recapture as much of the remaining energy as possible to help heat a number of our buildings. At McMurdo, we capture a total of 85 percent as useful energy; at the South Pole, we believe we are closer to 95 percent. With our light-vehicle fleet, I estimate we only get back 10 to 15 percent of the fuel's energy content. With an electric truck, the power comes from batteries that are charged by our powerplant, which is harvesting eight times as much energy from our fuel as the internal-combustion engine does. For light electric vehicles, McMurdo's environment is ideal.


So one upshot for ICE vehicles operating in Antarctica, seems to be heaters on everything, not just the engine: "....battery heaters, coolant heaters, transmission heaters, differential heaters."

Even more critically, all McMurdo vehicles are powered by special military-grade low-moisture gasoline or jet-fuel, i.e. fuels that can withstand extremely low-temperatures -- see http://en.wikipedia.org/wiki/Jet_fuel , http://generalaviationnews.com/2011/03/16/10-mogas-myths/ , and http://www.bp.com/en/global/bp-air/aviation-fuel/aviation-gasoline/about-mogas.html . So any vehicle or electric generator designed to withstand extreme Antarctic temperatures needs to have an ICE suitable for such fuels.

But in a hybrid vehicle the engine could just as well a microturbine range-extender, because turbines are so fuel-flexible, able to burn Jet fuel at one end, and Biodiesel at the other.


******************************


8.
A Serial Hybrid Power Train for All Seasons, All Altitudes, and All Fuels


******************************


Now of course I am not suggesting that a RTW expedition motorhome should be designed for driving in Antarctica. But I am saying that it should be designed to drive easily across the Canadian Prairies, Siberia, or the Tibetan plateau, in the middle of winter. Which means that, if necessary, it should be able to run on low-moisture Jet fuel, just like vehicles in Antarctica. A turbine like the Abrams' AGT1500 does just this.

Furthermore, I am also not suggesting that 6x6 expedition vehicle should be fitted with the Abrams AGT1500 turbine, if only because direct-drive turbines in automotive applications are so fuel inefficient. A microturbine only makes sense as a range-extender driving a generator in a serial hybrid solution. It does not make sense driving the wheels directly, except perhaps in a special application like the Abrams tank. See post #510 on the previous page for further discussion, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page51 .

Reflecting a bit, Mr. Blaisdell's position as USAP"s operations manager in Antarctica is clearly different than the typical overlander's, for the simple reason that Mr. Blaisdell can exert tight control over fuel type and quality. Whereas overlanders enjoy no such luxury. So even if ICE engines can be optimized to use high-quality Jet fuel in Antarctica, could these same engines be transplanted to the tropics, and work equally well burning low-grade diesel?

But that's exactly what a truly "world-class", go-anywhere expedition motorhome needs: an engine for all seasons, all altitudes, and all fuels. So perhaps a Capstone C30 or C65 microturbine is exactly the right solution.

Furthermore, a go-anywhwere RTW motorhome needs a complete power train for all seasons, all altitudes, and all fuels. In addition to the range-extending engine/generator, other elements in the power-train also need to be "cold-hardened" and "high altitude capable". For instance, how do Lithium-ion batteries hold up in extreme cold? And at extreme altitude? Do hybrid vehicles designed for extreme cold and high altitude yet exist?

This seems like a good place to stop, finishing with the focus still on microturbines.

To be continued......:)

All best wishes,



Biotect
 
Last edited:

dwh

Tail-End Charlie
A quickie...

I think the turbines can be quiet enough - in an ExPo truck (or a bus). There's not enough space in a car, but in a large vehicle you have more to work with. And as you pointed out, and ExPo truck is likely to have (or need) the intake up high anyway.

The jet only moves X amount of air, so as long as the ducting system is not restrictive, it shouldn't be an issue.

Noise baffling, or soundproofing are well understood arts and there are engineers who specialize in it. Recording studios always use sound absorption, or dampening materials of course, but many of them also use a floorplan which is designed to control sound or noise. They also tend to use what are called "sound locks" - like an air lock for sound.

So I think it's entirely possible to make the system essentially silent from ground level. Standing next to it, you wouldn't be able to hear it, or barely hear it.

But of course, there will still be *some* sound, and so that should be directed up out the top where it won't bounce back on the bystanders. Up to a point, sound waves can be controlled directionally.

Then there is the intake, which makes a healthy amount of sucking whining noise. Again, it's a matter of size - imagine a K&N filter the size of a door in a house - sucking the air to feed a 300cc engine through that wouldn't make any sound at all.

And you have both intake and exhaust noise problems with the air to run the engine, but you also have them with the air to cool the engine. For the exhaust from the cooling process, you have to control the mechanical noise of the engine. Again, high and large intake and exhaust, with baffled ducts, embedded in suitable dampening material should work.

I'm imagining something like this - but 5 or 10 times larger. A duct, not a muffler. But of course, I'd want to engage a proper engineering type to make sure it's designed so it will actually work:

flowcut2.jpg






It's all a question of size. If you ran a microturbine in a sound studio - you wouldn't hear it out in the parking lot.

I would shoot for a goal something like the Honda eu200i inverter generator, which I think is somewhere around 49db at 21'. A lot of people have commented on how pleasantly quiet that machine is.
 

dwh

Tail-End Charlie
But for a truck to grab a new RTW record, the sound wouldn't really be an issue; the locals can put up with it for a short while since the truck is going to be moving on after only a night or two at any single location.

Gotta run.
 

optimusprime

Proffessional daydreamer.
Quote


But, again, everything changes when one goes hybrid. To achieve 1.5 m fording capability, for instance, the huge battery pack between the rails would have to be completely waterproofed. Sure, this seems a natural enough requirement in any case, but for an expedition vehicle that might ford a stream 1.5 m deep, the waterproofing has to be extra-secure. And although as egn suggests, ICE vehicles seem somewhat immune to partial immersion in water, the same might not be true for a vehicle equipped with a microturbines?

So two additional, big questions arise when considering microturbines in a 6x6, globally capable expedition motorhome:

1. Locating and/or containing the microturbine(s), such that a MAN SX-series truck, or a Tatra 815 series truck, would still have 1.5 m fording capability

2. Locating the air-intake and exhaust, to enable the same


Quote
-----------------------------------------------------------------



Just to point out it's not just the engine air supply that limits wading depth. You have to raise the breathers on gearboxes,axles,fuel tanks etc,and in the particular case of (I'll use the term) motor homes, any air vents low down.
 
Last edited:

biotect

Designer
.
Just to point out it's not just the engine air supply that limits wading depth. You have to raise the breathers on gearboxes, axles, fuel tanks etc, and in the particular case of (I'll use the term) motor homes, any air vents low down.


Hi optimusprime,

Agreed. But presumably this globally capable RTW motorhome will be constructed on either a MAN SX-series chassis, or a Tatra 815 series. Both manufacturers have lots of experience creating vehicles for extreme military applications, vehicles that can almost "swim". When the MAN-KAT was first developed, the designers hoped to create a vehicle that would be completely amphibious. They had to drop this as a design specification because it became too expensive. But something like "almost amphibious" capability still lingers on in the overall design of the SX and HX.

Here are some images of the MAN SX and HX "swimming":


man_sx45_l1.jpg Picture 056.jpg Picture 024.jpg
Picture 023.jpg Picture 022.jpg Picture 025.jpg
m02009011200007.jpg m02009011200002.jpg m02007110100020.jpg
295_MANcatA1-12.jpg


And see posts #262 and #263, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page27 .

One of the more interesting amphibious vehicles I've come across recently is the Hagglunds BV206, originally developed for the Swedish Army to cope with boggy terrain in northern Scandinavia. The Hagglunds is fully amphibious, which means that when it falls through thin ice in Antarctica, not all is lost. Here are some rather incredible videos :




Also see https://www.youtube.com/playlist?list=PL9931701A7C97F694 , http://www.bv206.co.uk/index.php/videos , https://www.youtube.com/watch?v=rE_wAuBMv1I , https://www.youtube.com/watch?v=rnZ0CEd_qx0 , https://www.youtube.com/watch?v=0BDmdP6jNKs , https://www.youtube.com/watch?v=-l5xiMvMlBU , https://www.youtube.com/watch?v=mwr8Xy9FrzU , https://www.youtube.com/watch?v=MRuYUZmhQUQ , https://www.youtube.com/watch?v=fTrinY76bco , https://www.youtube.com/watch?v=qZrzkmNfOqc&list=PL822403B9015AAF02&index=12 , https://www.youtube.com/watch?v=ji6uk0RKupM&index=13&list=PL822403B9015AAF02 , https://www.youtube.com/watch?v=7UVwslNMoWM , https://www.youtube.com/watch?v=fGiPRI1l73s , and https://www.youtube.com/watch?v=XqdJRFfHSYs .

For more information about the Haaglunds BV206, as well as its technology-successor, the BAE Systems "Viking" BvS 10 M2 (Hagglunds was bought by BAE Systems), see http://en.wikipedia.org/wiki/Bandvagn_202 , http://en.wikipedia.org/wiki/Bv206 , http://www.bv206.co.uk , http://www.bv206.co.uk/index.php/models-available/personnel-carriers , http://www.bv206.co.uk/index.php/models-available/cargo-carriers , http://www.bv206.co.uk/index.php/what-is-a-hagglund-bv206 , http://www.bv206.co.uk/index.php/engine-choices , http://www.bv206.co.uk/index.php/specifications , http://www.bv206.co.uk/index.php/videos , http://www.hagglund-hire-scotland.co.uk/spec.php , http://www.army-technology.com/projects/bv2065/ , http://www.one35th.com/attc/attc_variants.htm , http://en.wikipedia.org/wiki/BvS_10 , http://www.baesystems.com/product/B...frWindowMode=0&_adf.ctrl-state=1dhtx6qhur_142 , http://www.deagel.com/Tracked-Armored-Fighting-Vehicles/BvS10_a000588002.aspx , http://www.military-today.com/apc/bvs10_viking.htm , http://www.armyrecognition.com/unit...ical_data_sheet_specifications_pictures_.html , http://www.army-technology.com/projects/viking/ , http://www.army-technology.com/news/news81144.html , and http://www.army-technology.com/projects/viking/viking8.html .

But for a RTW motorhome, Hagglunds-like amphibious capability is not necessary. Even fording depth up to 1.5 m is probably not necessary; 1.2 m would prove adequate.

As for air vents lower down in the camper: why do you think they would be needed? If the camper where completely free of LPG, there would be no danger of carbon monoxide poisoning or lingering LPG. So "drop down" vents (LPG is heavier than air) would no longer be necessary, and perhaps so too, vents higher up could be minimized.

There is some question whether or not the camper of the "TerraLiner" should be pressurized -- see posts #427, #428, #431, #432, #435, and #437 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page43 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page44.

I am now inclined to go with very mild pressurization, to keep out dust, but not to combat anoxia at high-altitude. As such, a "slightly pressurized" expedition camper would probably not have the standard air vents of a more mainstream motorhome. But please correct me if I am wrong about this!

All best wishes,



Biotect
 
Last edited:

biotect

Designer
Hi dwh,

Interesting response.

A quickie...

I think the turbines can be quiet enough - in an ExPo truck (or a bus). There's not enough space in a car, but in a large vehicle you have more to work with. And as you pointed out, and ExPo truck is likely to have (or need) the intake up high anyway.

The jet only moves X amount of air, so as long as the ducting system is not restrictive, it shouldn't be an issue.

Noise baffling, or soundproofing are well understood arts and there are engineers who specialize in it. Recording studios always use sound absorption, or dampening materials of course, but many of them also use a floorplan which is designed to control sound or noise. They also tend to use what are called "sound locks" - like an air lock for sound.

So I think it's entirely possible to make the system essentially silent from ground level. Standing next to it, you wouldn't be able to hear it, or barely hear it.


Agreed. Perhaps this is one reason why Capstone microturbines have so far been (somewhat) successfully applied only in big buses and trucks, as opposed to cars. Noise is clearly an important consideration, which is why I raised it as an issue. The noise of Jay Leno's EcoJet, or even the noise of the Capstone CMT-380 sports car, really surprised me. Whereas the New York pilot project buses seemed much quieter.

In addition to automotive applications, it's worth noting that Capstone is generating interest amongst those looking for clean, efficient power for marine applications. For instance, back in 2010 Capstone partnered with Electric Ship Facilities to create a "hybrid" diesel-electric boat -- see http://www.motorship.com/news101/engines-and-propulsion/marine-genset-powered-by-gas-turbine , http://www.maritime-executive.com/article/new-hybrid-electric-boat , http://www.capstoneturbine.com/news/story.asp?id=555 , http://www.electricshipfacilities.com/eng/ , http://www.electricshipfacilities.com/eng/NEWS/ESF-and-Capstone-Turbine-Corporation-sign-agreement , http://www.electricshipfacilities.com/NIEUWS/Oude-nieuwsartikelen/ESF-welcomes-Capstone , and http://www.boatdesign.net/forums/hybrid/capstone-microturbine-39265.html :


carousel.jpg


Capstone also partnered with the Reagan Power company to sell microturbines for the marine market, under a new "Kilo-Pak" subsidiary. The gensets are called "Klean-Pak" -- see http://southernboating.com/blog/2011/01/14/engine-room-21/ , http://www.marineware-asia.info/brochure/KleanPak data sheet_Eng.pdf , http://www.superyachtnews.com/business/15797/reagan_launch_low_emission_generator_kleanpak.html , http://www.capstoneturbine.com/news/story.asp?id=589 , http://in.reuters.com/article/2010/10/28/idUS165374+28-Oct-2010+GNW20101028 , http://www.reaganpower.com , http://www.kilopak.com/partners.html , and http://manufacturing-today.com/index.php/featured-content/318-reagan-equipment-co-inc :


Picture 12 copy.jpg..... A-65kW-Klean101.jpg


But in both cases more recent information does not seem available, and it's hard to say where these initiatives now stand.

More recently, Capstone installed two C30 microturbines in the world's first dual-fuel diesel/LNG Type C Tanker, an inland barge called the MTS "Argonon", owned by Dean Shipping. The microturbines provide auxiliary power for the electrical system, and so too their exhaust is captured through a heat exchanger that heats up water to a temperature of 80°C-90°C. This hot water is then used to vaporise the LNG before it reaches the main engines, two dual-fuel Catepillar DF3512 engines rated at 1500 HP. The hot water also provides heat for the boiler and domestic hot water system, and heating as well as cooling (via an absorption chiller) for crew living quarters:


1-image.jpg Untitled.jpg 6-image.jpg

[video=youtube;9E1JEa-vUz8]https://www.youtube.com/watch?v=9E1JEa-vUz8&list=PLhuA58w83Z-EAxtab87vtWszbVVEd2sp7&index=1 [/video] [video=youtube;FGhjlegmW2w]https://www.youtube.com/watch?v=FGhjlegmW2w&list=PLhuA58w83Z-EAxtab87vtWszbVVEd2sp7&index=2 [/video]


See http://www.ship-technology.com/projects/mts-argonon-chemical-tanker/
, http://www.ship-technology.com/proj...ical-tanker/mts-argonon-chemical-tanker1.html , http://regattasp.com/casestudies/mts-argonon/ , http://www.rotterdamportinfo.com/editorial/edition-51th/new-bunker-barge-is-gas-propelled , http://articles.maritimepropulsion.com/article/First-dual-fuel-barge-to-sail-in-Europe69162.aspx , http://www.deenshipping.com/files/documents/Argonon PressMap_LRES.pdf , http://www.informatie.binnenvaart.nl/document/Argonon.pdf , http://www.bestfact.net/wp-content/...reenlogistics_2-048_Argonon_LNG_Dual_Fuel.pdf , http://www.capstoneturbine.com/_docs/CS_CAP406_Argonon_lowres.pdf , http://www.capstoneturbine.com/news/video/view.asp?video=mts-argonon-rotterdam-netherlands , and https://www.youtube.com/playlist?list=PLhuA58w83Z-EAxtab87vtWszbVVEd2sp7 .


**********************************

CONTINUED IN NEXT POST
.
 
Last edited:

biotect

Designer
.
CONTINUED FROM PREVIOUS POST


**********************************



Capstone also recently fitted a C30 microturbine in the "Lethantia" superyacht:


MME-Microturbine-Marine-Energy-6.jpg MME-Microturbine-Marine-Energy-11-731x411.jpg MME-Microturbine-Marine-Energy-7.jpg
Untitled3.jpg Untitled2.jpg steiner2.jpg


[video=youtube;vLTinWDhZNk]https://www.youtube.com/watch?v=vLTinWDhZNk [/video]


See http://www.yachtemoceans.com/mme-microturbines-superyacht-generators/ , http://www.mme-generators.com/sites/default/files/press/syr_the-microturbine-generator-arrives.pdf , http://thesuperyachtowner.com/feature.asp?featureid=19431 , http://www.superyachtworld.com/features/siegfried-steiner-interview-lethantia/ , http://www.superyachttimes.com/editorial/57/article/id/9492 , http://www.superyachttimes.com/yachts/details/1040 , http://www.superyachtnews.com/thesuperyachtreport/issues/tsrjmp146.pdf , http://www.theglobeandmail.com/globe-investor/news-sources/?mid=INFOLINK.20130605.10035307 , http://www.capstoneturbine.com/news/story.asp?id=688 , http://phx.corporate-ir.net/phoenix.zhtml?c=120708&p=irol-newsArticle_print&ID=1827222&highlight= , http://www.capstoneturbine.com/news/video/view.asp?video=lethantia-super-yacht , http://worldsuperyacht.com/yacht/lethantia , http://www.charterworld.com/?sub=yacht-charter&charter=lethantia-3065 , http://www.yachtcharterfleet.com/luxury-charter-yacht-23694/lethantia.htm , http://www.royalhuisman.com/en/yacht2489.html , http://www.royalhuisman.com/en/yachtdescription2489.html , http://www.royalhuisman.com/en/yachtgallery2489.html , and http://www.royalhuisman.com/en/yachtspecifications2489.html .

In the video about the "Lethantia" just above, the Capstone C30 microturbine is barely audible. So clearly, good soundproofing can make a difference.

Also see another video of "Lethantia" at http://www.royalhuisman.com/en/video_Lethantia.html , http://www.steiner-film.com/html-en/special-points-of-view/steiner-sy-lethantia-schooner.html , and http://www.nauticexpo.de/prod/royal-huisman/segel-yachten-kreuzfahrt-schoner-serie-20549-307710.html .


For the exhaust from the cooling process, you have to control the mechanical noise of the engine. Again, high and large intake and exhaust, with baffled ducts, embedded in suitable dampening material should work.

I'm imagining something like this - but 5 or 10 times larger. A duct, not a muffler. But of course, I'd want to engage a proper engineering type to make sure it's designed so it will actually work:

flowcut2.jpg


About the location of the microturbines' exhaust, very much agreed, high up and out of sight, that way allowing maximum fording capability, and also reducing noise at ground level.

But I was also wondering how the exhaust might be used to supplement the camper's heater and A/C systems, which presumably would be otherwise all-electric. There is still a great deal of energy available in that exhaust, which as you know is quite hot. Here I am thinking of some of the things written on Capstone's FAQ webpage -- see http://www.capstoneturbine.com/company/faq.asp :

Question:How are Capstone MicroTurbines used in CHP?

Answer: Our microturbine exhaust contains approximately 70 percent of the energy that was stored in the fuel. This results in exhaust temperatures approaching 371 degrees Centigrade. This clean exhaust can be put to use in three ways: *DIRECT: Use the exhaust directly for heating needs such as drying, process heating, et cetera; *HOT WATER: Use the exhaust to generate hot water or steam for domestic hot water, pool heating, space heating, et cetera; *CHILLED WATER: Use the exhaust to generate chilled water for air cooling, process water, et cetera.


Question:What is CHP?

Answer: CHP is an acronym for "combined heat and power", also known as cogeneration. It is a process that converts a fuel simultaneously into both thermal (steam, hot water, hot air) and electrical energy.


Question: How is heat recovered and used?

Answer:In CHP applications, captured exhaust heat can be used in three ways: *DIRECT: Porting exhaust straight from the microturbine and into the heating load; *HOT WATER: Using an air-to-liquid heat exchanger, create hot water or steam for circulating through the heating load; *CHILLED WATER: Using an absorption chiller, or other thermally-activated cooling technology, create chilled water for circulating through the cooling load.


Question:How much does heat recovery cost?

Answer: In CHP applications, heat recovery costs vary depending on the desired by-product: *DIRECT: Least expensive with the highest thermal efficiency, but requires design engineering to properly integrate the hot exhaust into the manufacturing process; *HOT WATER: More expensive because it requires the addition of a heat exchanger, exhaust ducting, and water piping to transport the hot water; *CHILLED WATER: Most expensive because it requires the addition of an absorption chiller, cooling tower, heat exchanger (if a hot water-fired chiller is used); and water piping to transport hot and cold water.

I don't know; what do you think? Could the Capstone microturbines' exhaust be used for camper cooling/heating? If so, how?

All best wishes,


Biotect
 
Last edited:

optimusprime

Proffessional daydreamer.
.



Hi optimusprime,

Agreed. But presumably this globally capable RTW motorhome will be constructed on either a MAN SX-series chassis, or a Tatra 815 series. Both manufacturers have lots of experience creating vehicles for extreme military applications, vehicles that can almost "swim". When the MAN-KAT was first developed, the designers hoped to create a vehicle that would be completely amphibious. They had to drop this as a design specification because it became too expensive. But something like "almost amphibious" capability still lingers on in the overall design of the SX and HX.

Here are some images of the MAN SX and HX "swimming":


View attachment 243482 View attachment 243483 View attachment 243484
View attachment 243485 View attachment 243495 View attachment 243496
View attachment 243497 View attachment 243498 View attachment 243499
View attachment 243500


And see posts #262 and #263, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page27 .

One of the more interesting amphibious vehicles I've come across recently is the Hagglunds BV206, originally developed for the Swedish Army to cope with boggy terrain in northern Scandinavia. The Hagglunds is fully amphibious, which means that when it falls through thin ice in Antarctica, not all is lost. Here are some rather incredible videos :




Also see https://www.youtube.com/playlist?list=PL9931701A7C97F694 , http://www.bv206.co.uk/index.php/videos , https://www.youtube.com/watch?v=rE_wAuBMv1I , https://www.youtube.com/watch?v=rnZ0CEd_qx0 , https://www.youtube.com/watch?v=0BDmdP6jNKs , https://www.youtube.com/watch?v=-l5xiMvMlBU , https://www.youtube.com/watch?v=mwr8Xy9FrzU , https://www.youtube.com/watch?v=MRuYUZmhQUQ , https://www.youtube.com/watch?v=fTrinY76bco , https://www.youtube.com/watch?v=qZrzkmNfOqc&list=PL822403B9015AAF02&index=12 , https://www.youtube.com/watch?v=ji6uk0RKupM&index=13&list=PL822403B9015AAF02 , https://www.youtube.com/watch?v=7UVwslNMoWM , https://www.youtube.com/watch?v=fGiPRI1l73s , and https://www.youtube.com/watch?v=XqdJRFfHSYs .

For more information about the Haaglunds BV206, as well as its technology-successor, the BAE Systems "Viking" BvS 10 M2 (Hagglunds was bought by BAE Systems), see http://en.wikipedia.org/wiki/Bandvagn_202 , http://en.wikipedia.org/wiki/Bv206 , http://www.bv206.co.uk , http://www.bv206.co.uk/index.php/models-available/personnel-carriers , http://www.bv206.co.uk/index.php/models-available/cargo-carriers , http://www.bv206.co.uk/index.php/what-is-a-hagglund-bv206 , http://www.bv206.co.uk/index.php/engine-choices , http://www.bv206.co.uk/index.php/specifications , http://www.bv206.co.uk/index.php/videos , http://www.hagglund-hire-scotland.co.uk/spec.php , http://www.army-technology.com/projects/bv2065/ , http://www.one35th.com/attc/attc_variants.htm , http://en.wikipedia.org/wiki/BvS_10 , http://www.baesystems.com/product/B...frWindowMode=0&_adf.ctrl-state=1dhtx6qhur_142 , http://www.deagel.com/Tracked-Armored-Fighting-Vehicles/BvS10_a000588002.aspx , http://www.military-today.com/apc/bvs10_viking.htm , http://www.armyrecognition.com/unit...ical_data_sheet_specifications_pictures_.html , http://www.army-technology.com/projects/viking/ , http://www.army-technology.com/news/news81144.html , and http://www.army-technology.com/projects/viking/viking8.html .

But for a RTW motorhome, Hagglunds-like amphibious capability is not necessary. Even fording depth up to 1.5 m is probably not necessary; 1.2 m would prove adequate.

As for air vents lower down in the camper: why do you think they would be needed? If the camper where completely free of LPG, there would be no danger of carbon monoxide poisoning or lingering LPG. So "drop down" vents (LPG is heavier than air) would no longer be necessary, and perhaps so too, vents higher up could be minimized.

There is some question whether or not the camper of the "TerraLiner" should be pressurized -- see posts #427, #428, #431, #432, #435, and #437 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page43 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page44.

I am now inclined to go with very mild pressurization, to keep out dust, but not to combat anoxia at high-altitude. As such, a "slightly pressurized" expedition camper would probably not have the standard air vents of a more mainstream motorhome. But please correct me if I am wrong about this!

All best wishes,



Biotect

Agreed,if your not having LPG on board, then there's no reason for lower mounted vents.
It's common practice to raise the breathers for the axles and transmission to the same height as the air intake for the engine,at least then you get peace of mind.

As for pressurising the cabin, that's what UAV do to their awesome camping trailers in Australia. They use a filtered automotive fan to keep the inside pressurised to keep out the dust.
 

optimusprime

Proffessional daydreamer.
.
CONTINUED FROM PREVIOUS POST


**********************************



Capstone also recently fitted a C30 microturbine in the "Lethantia" superyacht:


View attachment 243578 View attachment 243579 View attachment 243580
View attachment 243583 View attachment 243582 View attachment 243581


[video=youtube;vLTinWDhZNk]https://www.youtube.com/watch?v=vLTinWDhZNk [/video]


See http://www.yachtemoceans.com/mme-microturbines-superyacht-generators/ , http://www.mme-generators.com/sites/default/files/press/syr_the-microturbine-generator-arrives.pdf , http://thesuperyachtowner.com/feature.asp?featureid=19431 , http://www.superyachtworld.com/features/siegfried-steiner-interview-lethantia/ , http://www.superyachttimes.com/editorial/57/article/id/9492 , http://www.superyachttimes.com/yachts/details/1040 , http://www.superyachtnews.com/thesuperyachtreport/issues/tsrjmp146.pdf , http://www.theglobeandmail.com/globe-investor/news-sources/?mid=INFOLINK.20130605.10035307 , http://www.capstoneturbine.com/news/story.asp?id=688 , http://phx.corporate-ir.net/phoenix.zhtml?c=120708&p=irol-newsArticle_print&ID=1827222&highlight= , http://www.capstoneturbine.com/news/video/view.asp?video=lethantia-super-yacht , http://worldsuperyacht.com/yacht/lethantia , http://www.charterworld.com/?sub=yacht-charter&charter=lethantia-3065 , http://www.yachtcharterfleet.com/luxury-charter-yacht-23694/lethantia.htm , http://www.royalhuisman.com/en/yacht2489.html , http://www.royalhuisman.com/en/yachtdescription2489.html , http://www.royalhuisman.com/en/yachtgallery2489.html , and http://www.royalhuisman.com/en/yachtspecifications2489.html .

In the video about the "Lethantia" just above, the Capstone C30 microturbine is barely audible. So clearly, good soundproofing can make a difference.

Also see another video of "Lethantia" at http://www.royalhuisman.com/en/video_Lethantia.html , http://www.steiner-film.com/html-en/special-points-of-view/steiner-sy-lethantia-schooner.html , and http://www.nauticexpo.de/prod/royal-huisman/segel-yachten-kreuzfahrt-schoner-serie-20549-307710.html .





About the location of the microturbines' exhaust, very much agreed, high up and out of sight, that way allowing maximum fording capability, and also reducing noise at ground level.

But I was also wondering how the exhaust might be used to supplement the camper's heater and A/C systems, which presumably would be otherwise all-electric. There is still a great deal of energy available in that exhaust, which as you know is quite hot. Here I am thinking of some of the things written on Capstone's FAQ webpage -- see http://www.capstoneturbine.com/company/faq.asp :



I don't know; what do you think? Could the Capstone microturbines' exhaust be used for camper cooling/heating? If so, how?

All best wishes,


Biotect

Depending on flow and pressure of the exhaust,could it not drive a turbine type generator for electric supply as well?
(I'll admit to knowing nothing about these)
 

Aspire

Observer
Look up "heat recovery ventilation" (HRV) and "Energy Recovery Ventilation" (ERV) for designs of heat exchangers that work very well.

As for a turbine - I looked into it, if for nothing else, then for the "cool" factor. However, I don't have easy access to JetA1, nor kerosene. Yes, a Turbine will run on diesel, but you don't want it constantly run on diesel, as that will make for quite the expensive repairs, and I really don't want the whine of a turbine destrying my hearing (it really is no good for your ears).

These threads would be great if they aimed more to reveal the cons and pros of different approaches, taking reality more into consideration. The turbine is a great example of that, as is the heat exchanger. It seems to me, that you should read more about passive houses (and in particular, the German Passivhaus standard) to get some good ideas on construction and what to avoid, as well as on the importance of heat exchangers and whatnot.

Then, before having this sci-fi vision with things such as jet turbines, take a look on practicalities such as running them on diesel (not good in the long run, although it will do it in a pinch), and the noise. The whine on big ones are bad enough - even with ear plugs in, but the smaller ones are even worse when it comes to whining.

It seems to me, that the more complex it can be made, the better, and I have yet to see any attempts to apply the knowledge you scrapbook from around the net. I'm missing a mission statement, as these threads seems more like a scrapbook, but very little (practical) engineering for a non-existant mission.
 

Forum statistics

Threads
185,531
Messages
2,875,588
Members
224,922
Latest member
Randy Towles
Top