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MRAP light

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Providing the protection of a huge MRAP in a HMMVW sized package: physics gone wild

http://blog.wired.com/defense/2008/11/radical-weight.html

Army May Place Massive Orders for Hulking Trucks
By Nathan Hodge November 17, 2008 | 2:49:00 PMCategories: Ground Vehicles 

After investing in a fleet of over 10,000 Mine Resistant Ambush Protected (MRAP) vehicles, the Pentagon is preparing to buy more -- lots more.

The super-sized trucks have been credited with saving many lives, but as reported here previously, the Pentagon's new ride has fared poorly in some terrain: the trucks are too heavy for the primitive roads of Afghanistan; too wide for the alleyways of Iraq; and they are prone to rollover. The military now wants a scaled-down version that will combine the off-road agility of a Humvee and the survivability of an MRAP.

But the real news here is the potential scale of the "MRAP Lite" buy: the Army may buy as many as 10,000 of them. On Friday, the Army posted a pre-solicitation announcement for a vehicle called the MRAP All-Terrain Vehicle, or M-ATV. The announcement -- issued in response to an urgent request from the field -- says the M-ATV order could run from a "probable" production quantity of 2,080 vehicles up to a maximum of 10,000 new trucks.

That's a lot of new trucks. Potential bidders are being asked to deliver five test vehicles for MRAP Lite; the Army will then select as many as five models for further testing. At the end of testing, the government may source vehicles from a single M-ATV producer -- or place production orders with multiple manufacturers.

Designing a nimble, survivable off-road vehicle will push the boundaries of design. The new vehicle is supposed to incorporate protection against explosively formed projectiles and rocket propelled grenades, and that probably means bulking up with an extra layer of armor. While effective defenses have been developed against such threats, the addition of EFP and RPG protection has driven up the weight of the standard MRAP. 

Making a vehicle that is both light and survivable is also the goal of the Joint Light Tactical Vehicle, a project to develop a next-gen successor to the Humvee. The Pentagon recently picked three finalists in the JLTV contest. But with more money going to mini-MRAPs, one has to wonder where the money is going to come from for the next-generation truck buy.

With a production run of up to 10,000 vehicles, we should get in on this program to tap economies of scale and replace the G-Wagon, LSVW and MILCOT in one go.
 
Thucydides said:
Providing the protection of a huge MRAP in a HMMVW sized package: physics gone wild

http://blog.wired.com/defense/2008/11/radical-weight.html

With a production run of up to 10,000 vehicles, we should get in on this program to tap economies of scale and replace the G-Wagon, LSVW and MILCOT in one go.

Do we still use the G-Wagon?
 
Something like this can help keep the mass budget down on MRAP light, or other wheeled vehicles for that matter (scaled up for LAVs?)

http://news.cnet.com/8301-13639_3-10098240-42.html?tag=bnpr

New honeycomb tire is 'bulletproof'
Posted by Mark Rutherford Print E-mail Share 32 commentsYahoo! Buzz

The University of Wisconsin-Madison and a Wausau, Wis., company have come up with a 37-inch, bullet and bomb-proof Humvee tire based on a polymeric web so cool looking there's no need for hub caps.

Resilient Technologies and Wisconsin-Madison's Polymer Engineering Center are creating a "non-pneumatic tire" (no air required) that will support the weight of add-on armor, survive an IED attack, and still make a 50 mph getaway. It's basically a round honeycomb wrapped with a thick, black tread.

The military wants an alternative to the current Humvee "run flat" tires, which despite the name, still need a minimal amount of air pressure to roll and can leave troops stranded after being shot or blown out.

"You see reports all the time of troops who were injured by an IED or their convoys got stranded because their tires were shot out," said Resilient's General Manager Mike Veih. "There's all sorts of armor on the vehicle, but if you're running in the theater and get your tire shot out, what have you got? You've got a bunch of armor in the middle of a field."

In developing the design, the Wisconsin team studied other airless tires, like the Michelin "Tweel," but in the end settled on lessons learned from nature.

The patent-pending design mimics the precise, six-sided cell pattern found in a honeycomb and best duplicates the "ride feel" of pneumatic tires, according to the developers.

"The goal was to reduce the variation in the stiffness of the tire, to make it transmit loads uniformly and become more homogenous," said mechanical engineering professor Tim Osswald. "And the best design, as nature gives it to us, is really the honeycomb."

This particular geometry also does a great job of reducing noise and heat levels while rolling-two common problems with past models.

Costs per tire are expected to be the same or less than current units. Delivery is anticipated for 2011.
Mark Rutherford is a West Coast-based freelance writer. He is a member of the CNET Blog Network, and is not an employee of CNET. Email him at markr@milapp.com. Disclosure.
 
Looks promising, less prone to sidewall punctures as well.  The polymer, I'm sure, could also be optimized for terrain/conditions - ie grippier/more flex for sub-zero/deeper snow/cold conditions, firmer for mostly road use, a different variation for x-ctry use depending on sand or rocks.

One concern could be life - how many flex cycles do the honeycombs survive for, and the penchant for the gaps in the sides to pick up rocks, dirt, trash, etc, which could reduce life expectancy and effectiveness.

Even in a LAV application if 2 of 4 tires were 'special' ones, they'd be enough to get a wagon out of a kill zone and maybe prevent it from becoming an "M" kill in the first place.
 
Thinking about the MRAP light (since thinking about the current political news is enough to unbalance most human minds  >:D), I have come to some conclusions should this become a made in Canada solution (as part of FFCV, for example. Maybe we can claim it as part of the $30 billion stimulus package!). Of course anyone making such a vehicle should be coming to similar conclusions.

1. The vehicle should have a faceted shape, similar to WWII German light armour. Early models of half tracks and armoured cars had very elaborate facets, while late models were drastically simplified for ease of production and lower unit cost. This will provide protection from multiple angles, mines (under the vehicle), IED's (generally from the sides), EFP warheads (sometimes placed at window height) and so on.

2. The enemy are not dummies, so the MRAP/FFCV light will need to accommodate stand off armour (the RPG cage) and possibly active defense systems. Vision, sensors, weapons traverse, entry and exit points and vehicle attachments (lift points, jerry can holders etc) all have to be designed to operate with the add-ons from the start.

3. A serial electric drive should be given consideration for the drive train. Silent run-up, remote weapons mounts and the ability to power sensors and active defense systems can be easier if the vehicle starts with a generous on board power supply. Mounting the motors in the wheels also frees up internal space (no transmission or differentials) and reduces the number of weak points in the hull and drive train (no drive shafts).

4. The electrical system and electronics will contribute a great deal to the cost and weight unless the design is very carefully monitored. Since the Good Idea Cut Off Date (GICOD) is often superseded by the Absolutely Brilliant Idea Cut Off Date (ABICOD), electronics should be treated more like an aircraft, with a data bus able to accommodate the bells and whistles. Instead of having a dozen "boxes" at each crew station, something akin to a hardened laptop or tablet computer should be provided as the interface with the vehicle systems, communications devices, GPS etc. (I have seen ruggedized tablet computers which were the radios and GPS, as well as Linux based computers, using built in radio cards and VoIP software for the voice transmissions)

5. Advanced materials is a must. Materials like Graphine or advanced polymers like Spectra have strength to weight ratios far greater than steel, which may be the only way to come in under the weight budget. While repairs will be different or difficult, vehicle design like space frames covered in panels of advanced materials should provide some balance. Aerogels in the interior act as blast/spall liners and provide insulation. The polymer wheels mentioned in a previous post also provide a means to increase mobility and perhaps reduce weight.

6. Crew accommodations must be updated as well. Form fitting seats, five point harness' and internal padding (provided by the spall liner) are a minimum.

If this is done right, we can have the equivalent to the HMMVW; a basic platform which can be adapted to multiple uses. Mud Recce, utility truck, liaison vehicle, ambulance, linelayer, CP van.....the more adaptable it is the greater the economy of scale and the lower the unit cost.
 
While not MRAP class vehicles, I think these are examples of what the military would like to see in terms of size, weight and performance for the MRAP light. A vehicle with the crew layout of the Jackal would work well as a patrol vehicle, mud recce vehicle and weapons platform, but a utility or logistics vehicle would need a much different internal layout:

http://www.militaryweb.de/archives/114

Lexikon | New Vehicles: Keeping up with a changing battlefield

Freitag, 20. Juni 2008 | Autor: Robert J. Galbraith

American forces in Afghanistan are field testing a new generation of vehicles that can handle the hostile conditions of the countries’ challenging terrain. With mountains, powdery sand and sharply inclined valleys filled with boulders and other natural barriers, it makes it difficult for conventional vehicles to provide basic ground transportation, and the ability to lend adequate troop support. One vehicle undergoing testing is the ‘enhanced logistic off-road vehicle,’ known as the ELSORV.

“This vehicle was brought on as an operation need,” said Charlie Copsey, one of the engineers who built the ELSORV. “Rapid Equipment Force funded the building of the prototypes.”

For the past year, three test vehicles were put through operational assessment in the US. Now they are being put through the grinder in Afghanistan, by being tested by the soldiers who could eventually end up using the vehicles in battle.

The design goal of the ELSORV is to make it perform like a mechanized infantryman. That is, to be able to climb or manoeuvre anywhere that a soldier might, as long as there’s a space for the vehicle to squeeze through.

The ELSORV, with their modified Humvee engines can carry 2,700 pounds, drive up to 140 km/h on a hard road surface and manoeuvre a slope of 80 degrees. It has a high clearance, which means it avoids getting hung-up on obstacles such as boulders and tree branches.

First test results are very positive, according to soldiers from Combined Task Force Currahee, who are conducting the field tests. “The ELSORV is unlike any other military vehicle I’ve driven,” said Army Sgt. Lance Davis, one of the test drivers. “It goes wherever you want it to go.”

The ELSORV design is based on a similar vehicle designed for SOCOM (Special Operations Command). That vehicle, SRATS (Specialized Reconnaissance Assault and Transport System) is suitable as a Special Forces vehicle, in that it is an open cab, while ELSORV is closed.

The ELSORV can be equipped with an armour kit that protects against 7.62mm rifle bullets.

The decision on whether the ELSORV will become a part of the US Military hardware should be expected soon.

On the British side of advancing mechanized technology is the new Jackal 4X4 patrol vehicle. Put through its paces in Helmand province, the recent introduction of up to 100 of these new vehicles are an important advancement over the current Land Rover-based Weapons Mounted Installation Kit (WMIK).

The Jackal incorporates a fully-integrated protection system and reinforced armour plating, but its main defences are its mobility and agility, which makes the Jackal perfectly suited to southern Afghanistan where speed and manoeuvrability are an absolute necessity.

Carrying combinations of .50 calibre (12.7mm) machine guns, Heckler & Koch 40mm grenade launchers and General Purpose Machine Guns, these offer the Jackal overwhelming firepower. The weaponary along with its manoueverablity mean a greater flexibility in the conduct of ground operations.

With its 5.9litre engine, the 7-ton Jackal can reach a top speed of 130km/h and 80km/h off-road, with a range over 500km’s. A distinctive airbag suspension system allows for a more stable firing platform that can lift the vehicle more than a metre off the ground to clear obstacles and to offer a better view of the field of operations.

Major Tom Wood, part of the team that produced the vehicle, said:

“I don’t think we, as an Army, have ever bought such an incredible piece of kit before. It packs as much power as some of our tanks.”

Jackal specs;

Crew: 2+1
Length: 5.39m
Width: 2.00m
Height: 1.97m (not including weapon system)
Weight: 6,650kg
Engine: 5.9 litre Cummins ISBe Euro3

Jackal is ready to receive the British Armed Forces’ new BOWMAN communications equipment.

Another recent vehicle addition to the British Army (and the Royal Air Force) is the 7-ton, four-seater Panther Command and Liaison Vehicle (CLV). By the summer of 2009, it will be replacing some of the in-service CVR(T)s, TUMs, Saxon and FV432 vehicles, which are reaching the end of their operational lives.

The first 56 vehicles were delivered in 2007, and a total of 401 Panthers are slated to be delivered by 2009. They will be in widespread use for: Various Commanders, Sergeant Majors, and Liaison Officers for Armoured, Armoured Recce and Armoured Infantry Units.

Based on a design by Iveco Defence Vehicles of Italy, it is designed for strategic and tactical mobility with a high level of protection against anti-tank and anti-personnel mines. With a low stealth profile, the structure is modular with tuneable armour protection.

The design was conceived to create the maximum distance and protection between a mine explosion and the cabin. Wheel stations are located away from the crew cabin so that if it hits an anti-tank mine, the explosion is vented upwards, leaving the crew cabin undamaged.

The underside of the vehicle is v-shaped and the ground clearance has been maximised to allow maximum dissipation of the blast, therefore protecting the vehicle from an underbelly blast. This same undercarriage is composed of a three-layer sandwich construction, that collapses upon detonation of a mine underneath, helping absorb a high percentage of the blast that has not been expelled sideways.

Inside the cabin there are two adjustable anti-mine front seats and three foldable anti-mine back seats. These help reduce residual and secondary mine explosion effects on the crew. The seats are also suspended rather than fixed directly to the floor. This set up avoids direct transmission of the shockwave to the crew.

The rear body is fitted with a canvas roof and separates from the cabin in the event of a mine detonation under a rear wheel.

Protection can be suplimented by add-on armour packs which provide protection against small arms fire, or by the addition of a heavier kit which protects the vehicle against ambush including mines.

The Panther will be fitted with BAE Systems Self-Defence Weapon station (SDW). SDW combines BAE Systems Target Acquisition Weapon Sight (STAWS) with the AEI Enforcer Remote Controlled Weapon Station (RCWS). The weapon station is armed with a 7.62 mm L7 general purpose machine gun which can be upgraded to a 12.7 mm weapon if required, or a 40mm automatic grenade launcher.

The Panther is air transportable, and two vehicles can be under-slung beneath a Chinook helicopter to be transported at the same time .

Panther Specs;

Wheel Base ——— 3,200mm
Track —————–1,710mm
Lengh—————–4,687mm
Width—————–2,050mm
Height—————-1,950mm
Weight—————6,500kg
Payload————–2,900kg
Towing Capacity — 4,200kg.
 
One of the exhibits at Eurosatory 2008: the GEFAS by Rheinmettal. No other info right now, but this seems to fall in the MRAP light category:
 
That vehicle is one of many types that have been noticed by those working on the Tactical Armoured Patrol Vehicle (TAPV).  Some may recall this project having been published in the media:  http://forums.milnet.ca/forums/threads/81408.0.html

The project will replace the RG-31 (which was never intended to be permanent), G-Wagon, Coyote and Bison.  Hopefully the Cougar EOD Tm vehicle gets added to this list (or to the LAV III mid-life upgrade).  It works well for US teams, but is less than optimal with the Canadian teams' large robot.  It filled a temporary capability need when purchased, but unfortunately the decision was made to drop the EOD team vehicle project & buy more Cougar in the follow-on phases of EROC.
 
Another technology that can put the "light" into MRAP light goes commercial:

http://www.technologyreview.com/energy/22328/?nlid=1878

Wheel Motors to Drive Dutch Buses
The technology moves out of the lab and into commercial vehicles.
By Kevin Bullis

A company based in the Netherlands called e-Traction has developed a new kind of hybrid bus that uses in-wheel electric motors to improve efficiency and a GPS system to reduce pollution in congested areas of a city. The bus is a series hybrid: a diesel generator charges a battery, which in turn supplies electricity for two motors, one in each rear wheel. Thanks largely to its in-wheel motors, the bus can travel twice as far as a conventional bus on a liter of diesel, says Arend Heinen, who is both an engineer and spokesperson for the company. That translates into a reduction in fuel consumption of 50 percent. The company has been awarded contracts to retrofit seven commercial buses with its technology, with the first to be completed next month.

In-wheel motors have been around for some time: they have been used in several concept cars and experimental, low-production vehicles. But with the exception of electric bicycles, the idea has never found its way into a mass-production vehicle, says John Boesel, the president and CEO of Calstart, a nonprofit based in Pasedena, CA. The use of e-Traction's system in commercial buses would be a step toward more widespread use.

As with other hybrid buses, thousands of which are already in use in the United States, e-Traction's design saves fuel by capturing energy from braking, using it to generate electricity that can later be employed for acceleration. The in-wheel motors confer additional savings by eliminating the need for a transmission, differential, and related mechanical parts. That reduces both the overall weight of the bus and energy losses due to friction. Hybrid buses typically see fuel-cosumption reductions of about 25 to 30 percent compared with conventional buses, but e-Traction's design offers 50 percent reduction. In certain conditions--at low speeds in frequent stop-and-go traffic--some other hybrid buses have seen similar fuel-economy improvements. The in-wheel motors can also improve traction by allowing precise control over each wheel, and they allow for greater flexibility in vehicle design since there is no need to mechanically link the wheels to an engine.

The bus also incorporates a GPS-based system that changes the way that the bus operates in congested areas. In ordinary operation, the generator cycles on and off, keeping the battery at an optimal state of charge. But when the GPS system senses that the bus has entered an area of the city that usually sees a lot of traffic, the generator switches off to reduce emissions. The battery stores enough power to propel the bus for an hour without the generator running to recharge it.

E-Traction's key innovation, Heinen says, is in the design of its wheel motor. Typically, electric motors are designed to spin much faster than the rate of the wheels in order to generate the desired power. But such motors require gears to step down the revolutions per minute, which adds complexity and decreases efficiency. The company has eliminated the need for these gears by designing a large-diameter motor that can deliver the needed torque at low RPMs.

In-wheel motors have met with limited success in the past. In part, that's because it's been difficult to coordinate motors that have no mechanical connection to each other, a problem that the company says it's solved by developing a proprietary electronic control system. But there could be remaining issues. Putting the motors in the wheels places larger demands on the suspension (it has to be stronger to hold on to the much heavier wheels) and can make the motor and electronics more vulnerable to damage, both of which can reduce reliability. "There's little between the wheel and potholes," says Bill Van Amburg, senior vice president at Calstart. Dan Pederson, a researcher at the National Renewable Energy Laboratory, says that the large in-wheel motor is likely very expensive, which could make the system hard to justify without government subsidies.

Heinen says that four years of testing of a prototype system have convinced the company that the reliability issues have been addressed, and that costs for the motor may come down with larger-scale production. In addition to hybrid buses, e-Traction is working on hybrid garbage trucks and is retrofitting a Mercedes G SUV in an effort to move into the passenger-car market.

Copyright Technology Review 2009.
 
Thucydides,

I think you're confusing the JLTV project with MRAP-Light, which is now known as MRAP-ATV.

JLTV is the eventual replacement for the HMMMWV, and MRAP 1 series of vehicles in US service, which may be utilizing a number of the technologies you described, i.e. electric drive, composite armour, etc.

MRAP Light/MRAP-ATV is an interim program that is designed to bridge the gap between the current MRAP 1 category of vehicles and JLTV, with the majority of emphasis being put towards taking proven technologies and MRAP design features, decreasing the weight and size of the vehicle, and increasing cross country mobility.  Rapid delivery of an already proven platform system is the primary concern for this program.

Defense Update did a pretty good overview of the MRAP-ATV program and the likely candidates.
http://defense-update.com/features/2009/march/110309feature_matv.html

The whole MRAP-ATV program is pretty speedy, with the RFP going out in december, the trial vehicles being purchased this in March/April of 2009, and a contract award going out in May, with initial deliveries being taken in Sept/Oct.
 
Oshkosh was just awarded the $1.05B (US) contract to supply the US Army and Marine Corps with 2,244 of their M-ATV vehicle for the 'MRAP Light' program.

http://www.oshkoshdefense.com/defense/products~matv~home.cfm
 
High energy density electric motors will make MRAP light more of a reality, and this technology has many other applications as well:

http://nextbigfuture.com/2009/07/china-has-100-million-electric-bikes.html

Higher Power Nanocrystalline Core Electric Bike Motor from Texas

The device is an electric motor with a nano-crystalline core. It is the size of a casserole dish, and more powerful than a 600cc motorcycle engine. Okonsky’s company, KLD Energy, is supplying the motor to the Vietnamese motorbike company Sufat and by the end of the year he expects to startle Hanoi with something it has never seen before — a clean, quiet electric scooter that can accelerate from zero to 60 miles per hour in under 10 seconds.

The main difference, though, is that KLD’s electric motors are simply much stronger than those on traditional electric scooters, because they use a different technology. Electric motors work by alternating the polarity of several magnets back and forth, causing a rotor to spin. Most materials release heat each time their polarity shifts, and if the frequency of alternation goes too high, the motor will overheat.

But the nano-crystalline material at the core of a KLD motor scarcely heats up when its polarity shifts. That means the motor can alternate much faster, generating more power.
The KLD motor is so strong and so small that it doesn’t need a drivetrain, or gears. It is simply built into the motorbike’s rear wheel, which it turns directly, like pedaling a unicycle. Eliminating the drivetrain saves energy and improves reliability — there are fewer parts to break down.

The new bikes are slated to sell for between $1,500 and $2,000 U.S. dollars. That’s a reasonable price in the Vietnamese market; a mid-range Honda Future gas-powered bike sells for $1,700, while more chic bikes, such as the Piaggio Honda SH, sell for $4,000 or more.

KLD Energy Technology's nanocrystalline core electric motor

The high-performance motor system's technology innovates in several key areas to drive performance:

* With a high-frequency to low RPM ratio, the motor system does not require a transmission.
* Through the use of an innovative nano-crystalline composite material the motor conducts energy ten times more efficiently than traditional iron-core motors, eliminating the need for additional cooling mechanisms and enabling greater responsiveness.
* As a result of the more efficient material used to build the motor, it can achieve 2500 hertz, outperforming traditional motors' 250 hertz average.
* The system's computerized motor controller is designed specifically to perform and respond to the higher-frequency output of the motor
 
Another engine technology that has the potential to power more than just "light" vehicles. The improvement in fuel economy and power output does have greater consequences in light vehicles though:

http://www.technologyreview.com/energy/23156

Supercritical Fuel Injection

A supercritical diesel engine could increase efficiency and cut emissions.
By Duncan Graham-Rowe

Researchers in New York have demonstrated a supercritical diesel fuel-injection system that can reduce engine emissions by 80 percent and increase overall efficiency by 10 percent.

Diesel engines tend to be more efficient than gasoline, but the trade-off is that they are usually more polluting. Because diesel is heavy, viscose, and less volatile than gasoline, not all the fuel is burned during combustion, resulting in carbon compounds being released as harmful particulate soot. The higher combustion temperatures required to burn diesel also lead to increased nitrogen oxides emissions.

A fluid becomes supercritical when its temperature and pressure exceed a critical boundary point, causing it to take on novel properties between those of a liquid and a gas. George Anitescu, a research associate at the Department of Biomedical and Chemical Engineering at Syracuse University in New York state, who developed the new engine design, says that supercritical diesel can be burned more efficiently and cleanly.

By raising diesel to a supercritical state before injecting it into an engine's combustion chamber, viscosity becomes less of a problem, says Anitescu. Additionally, the high molecular diffusion of supercritical fluids means that the fuel and air mix together almost instantaneously. So instead of trying to burn relatively large droplets of fuel surrounded by air, the vaporized fuel mixes more evenly with air, which makes it burn more quickly, cleanly, and completely. In a sense, it is like an intermediate between diesel and gasoline, but with the benefits of both, says Anitescu, who presented his work last week at Directions in Engine-Efficiency and Emissions Research, a conference held in Dearborn, MI.

In the past, another related approach, called homogeneous charge compression ignition, has been used to improve the performance of diesel. This involves premixing diesel and air before injecting it as a vapour into a combustion chamber under high pressure. But while this mixture burns more efficiently, it also makes combustion more difficult to control, which can lead to engine knocking: shockwaves within the engine's cylinders caused by pockets of unburned fuel and air. In contrast, supercritical diesel injection produces very small vapour-like droplets, but with fuel densities equivalent to a liquid, says Anitescu.

Andreas Birgel, a researcher with the Internal Combustion Engines and Fuel Systems Research Group at University College London, UK, says there is plenty of interest in producing diesel that vaporizes more easily, for example, by using corn or rapeseed oil to make biodiesel, which has a relatively low viscosity. Another approach is to treat conventional diesel with additives, he says.

In order for the diesel to reach a supercritical state, Anitescu's fuel system has first to heat it to around 450 degrees Celsius at a pressure of about 60,000,000 Pascal. Achieving the pressure is not a problem, Anitescu says, but increasing the temperature is more demanding.

Because fuel systems usually operate at temperatures below 80 degree Celsius, Anitescu and his colleagues used the heat from the engine's exhaust to raise the fuel's temperature. This causes further complications. "You need to prevent it from coking," he says. Coking occurs when hydrocarbons in the fuel react, producing sticky deposits that can lead to fuel-system failures. The phenomenon can be avoided by diluting the fuel with an additive, such as carbon dioxide or water. In the Syracuse engine, a small amount of exhaust gas is introduced to act as an anticoking agent, a technique known as exhaust-gas recirculation.

The system has only been tested in a laboratory setup, but a prototype could be ready for testing by the end of the year, says Anitescu. The fuel system is designed to use conventional fuel injectors, even though these are designed to work with regular fluids. Anitescu says it may be possible to improve the performance by switching to a fluid state just below supercritical. This may allow vaporization to occur while getting better performance out of the injectors. "We have many options here," he says.

At the same conference, Transonic Combustion, a company based in of Camarillo, CA, presented details of an alternative way to use supercritical fuels that involves a novel fuel injector and redesigning the engine's entire valve system and combustion chamber.

But with either approach, going supercritical does not come without a cost, says Birgel. "You still need the viscosity because most diesel fuel systems depend upon the fuel for lubrication," he says.

"This is an issue which has yet to be addressed," admits Anitescu. He says it may be possible to introduce lubricants, but this would only be necessary in the final stage of the fuel system, where the fluid is at its hottest. For subcritical fuels, it may not be an issue, he says.
 
Now the MRAP light isn't really a project any more, but the principles need to be studied and applied to our own next generation of vehicles (FFCV or whatever acronym of the month is). Projects like Leopard II upgrades, the next new recce vehicle, patrol vehicles and even mundane equipment like MLVW class trucks, Milcots and G wagons will benefit from incorporating lighter, more powerful or more fuel efficient equipment, with overall improvements in performance (higher power/weight ratios, lower ground pressure) and smaller logistical footprint in terms of direct fuel consumption and indirectly as transports like ships, trains and aircraft have less weight to haul around.

Titanium is as strong as steel but far lighter, here is a new method of manufacturing Titanium components which could allow for interesting rebuilds/retrofits to reduce weight by a considerable factor (replacing steel components with lightweight titanium ones):

http://nextbigfuture.com/2009/08/low-cost-titanium-manufacturing.html

Titanium Manufacturing With Eight Times Lower Cost

Finished Titanium parts from Titanium Hydride can be over 8 times cheaper than regular titanium manufacturing. ($25/lb versus $213/lb)

A titanium powder developed during a DOE/GIPP project appears to produce a product with mechanical properties sufficient for a propulsion application from a very low-cost press and sinter process

* Could replace costly ingot processed forgings
- Eliminates yield loss associated with ingot forging
- Greater than 50% cost reduction predicted from yield savings alone
* Unique properties are developed during sintering of TiH2
- High density –critical to fatigue initiation
- Fine-grain size –import to reduce fatigue crack propagation

* Cummins Inc. has identified a relevant application using the Ti6Al4V alloy and provided the requirements to adequately assess the performance of the press/sinter/forged bars produced from TiH2

Test bars are to be fabricated at the commercialization partner of the DOE/GIPP project, ADMA Products Inc. ADMA has been producing approximately 35,000 lbs of TiH2powder per year in the Ukraine.
 
Going by first hand accounts from US troops in the sanboxes, the current MRAP have quite the bad habit of rolling over.
 
I believe that was one of the issues the (former) MRAP Light program was supposed to address.

If we round up the various technologies listed in this thread, there is the technical ability to create lightweight, fuel efficient protected vehicles (with accordingly reduced ground pressure and increased cross country performance). Issues like high centers of gravity can also be addressed in a clean sheet of paper design, while selective retrofits "could" improve existing designs.

Even non MRAP class vehicles like the LAV III could benefit from things like replacing the center tires with the polymer "solid" tires, high efficiency engines and replacing items like hatches and the rear ramp with equivalent items made from lightweight materials. It just takes willpower and resources.
 
Colin P said:
Going by first hand accounts from US troops in the sanboxes, the current MRAP have quite the bad habit of rolling over.

Well i hope what these guys do isn't one of the causes for rolling.

"Marines Ghost Ride the MRAP"

http://www.youtube.com/watch?v=BXl3Pdxrn-k
 
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