U.S. Army Pursues One-Fuel Strategy for Piston Engines

One long-standing objective of the U.S. Dept. of Defense is to adopt a single fuel that can be used in everything from battlefield vehicles and drones to stationary generators and heaters.

The DOD and NATO have adopted JP-8, a kerosene-based jet fuel, as their standard for continuous-burn aircraft engines. But modifying diesel or gasoline engine systems to use JP-8 is difficult because of a lack of basic research about the behavior of the fuel in piston engines, according to the U.S. Army.

This summer the Defense Dept. opened a facility to conduct such development within the Army Research Laboratory (ARL), which is a part of the Army's proving ground in Aberdeen, Md. The Army says the new lab is the only one of its kind within the DOD.

The goal of the ARL research is to help military contractors build piston engines that can optimize the use of JP-8. Switching to a single fuel would vastly simplify the logistics and cost of military operations.

The lab's combustion work is being led by Chol-Bum Kweon, a former General Motors Co. engine and fuel researcher. He notes that calibrating an array of engines designed for different duty cycles to burn one fuel raises major challenges in such areas as lubrication, fuel handling, injection, compression pressures, vaporization and combustion.

Kweon's team uses a special combustion chamber that can operate at pressures and temperatures as high as 150 bar (2,200 psi) and 1,000 K (1,300 F), respectively. The Army notes that GM and Caterpillar Inc. own earlier-generation versions of the test chamber. The device can be configured to study the dynamics of fuel spray, spray and combustion and exhaust gas recirculation.