Representatives of the news media assembled on the grounds of Universal Studios in Orlando, Florida for a demonstration of a new hybrid-electric HMMWV (Humvee). In a steady drizzle, a standard diesel-powered "Hummer" rumbled into view and slowly approached the damp, but curious group of reporters. It quickly became apparent that something was amiss, this wasn't the vehicle the press had come to see. Instead, with their attention momentarily diverted, the real hybrid-electric Hummer silently crept up from behind to within inches of the crowd before the announcer asked the assembly to turn around to view what some are calling the Army's new "Corvette in Camouflage."
You couldn't have asked for a more effective demonstration of the stealth capabilities of this one-of-a-kind prototype military vehicle. The result of a joint engineering effort by a consortium including the US Army's Tank-Automotive and Armaments Command (TAC), DARPA, the Southern Coalition for Advanced Transportation, Unique Mobility, PEI Electronics and others, the hybrid-electric HMMWV cost less than $2 million dollars in development costs, according to Daniel Tudor, senior program manager for PEI Electronics of Huntsville, Alabama.
While the Hybrid-Hummer looks like the standard Humvee on the exterior, complete with olive-drab and flat black camouflage, underneath its workaday fatigues is a remarkable power plant capable to surprising acceleration and speeds up to 80 miles per hour, a good 10 miles faster than the standard issue HMMWV. Its zero-to-fifty mph time is seven seconds, twice as fast as the stock model. It can climb a 60% grade at 17 mph, two and half times faster than stock. In addition, the vehicle gets twice the fuel economy at 18 mpg enabling it to carry a smaller fuel tank, while retaining the same 300 miles range. The vehicle can also ford streams up to a depth of five feet without swamping or stalling.
The only trade-off of the current prototype design is a 540 pound loss of payload, presumably taken by the heavy lead/acid batteries. The hybrid version has a rated payload of 1700 pounds, while the stock version is 2,240 pounds. The GVW for both vehicles is identical at 9,100 pounds.
The heart of this new generation military vehicle is its hybrid-electric propulsion system consisting of four 55kW brushless DC electric motors (peaked rated to 75kW), one for each wheel and a 1.9 liter turbo-charged diesel engine-generator set capable of turning out 55kW of electric power. The diesel-generator can provide power either to the drive train or to the vehicle's 288 VDC advanced lead/acid battery pack. Rated at 350 hp in hybrid mode, the combination gives the Hybrid-Hummer its sports car like performance, as well as its stealth capabilities which is activated by throwing a switch on the console between the two front seats. Going stealth turns off the turbo-diesel and draws power from the 85 amp hour battery pack giving the Humvee a 20 mile range in silent mode (40 miles using NiMH batteries). This virtually eliminates the vehicle's infrared signature, making it nearly invisible to enemy night vision devices. Large cutaway drawing.
Even with its turbo-diesel/generator running, the Hybrid-Hummer is amazingly quiet, both inside and out. EV World's editor in chief was able to video tape inside the vehicle during its last demonstration drive at the 14th Electric Vehicle Symposium and easily carried on a conversation with the driver. Click on the photo to the right for a RealVideo playback of that ride. Stealth mode is positively spooky! But for the crunch of the tires on the pavement, you can't hear this trooper coming. The noise you hear on the video is from an auxiliary generator powering lights at nearby exhibit tents.
Another advantage of individual electric drive to each wheel is the Humvee can be made to turn like a tank, locking or reversing the wheels inside the turn, giving the vehicle an unmatched turning radiu
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RE: Hybrid Humvee Brings Stealth To The Battlefield
What I find interesting about this is that it uses a similar drive system as a locomotive engine. It is nothing more than a diesel over electric drive sysytem with a battery backup. If you think about how much a train weighs and how efficient the engines are for the weight, it would make sense to find a way to incorporate that technology into the regular automotive sector. The comarisons to the stock vehicle are amazing. A 1.9 L engine with the assistance of batteries can accomplish the same tasks as the standard 6.5 L engine by itself. With better lighter batteries they can get the payload loss back. If they were to retain the original fuel tank, the range would be huge.
RE: Hybrid Humvee Brings Stealth To The Battlefield
Added to that Linus..if cars could brake the same way that the Diesel/electric Locomotive do (Dynamic Braking), then think of the cost savings on braking systems alone.
Hybrid Humvee Brings Stealth To The Battlefield
