Preliminary Development of a 30 kW Heavy Fueled Compression Ignition Rotary ‘X’ Engine with Target 45% Brake Thermal Efficiency
Abstract This paper presents initial progress in the development of LiquidPiston’s ‘X4’, a 30 kW heavy-fueled rotary compression ignition engine prototype. The X4 is the newest version of the unique rotary ‘X’ engine architecture. This development is partially funded by the Defense Advanced Research Projects Agency (DARPA), with broad dual-use civilian / military applications including UAVs, generators, and for propulsion. The 30 kW size may be of significant interest in the automotive application as a range extender for Electric Vehicles. The final performance objectives of the program are aggressive: 45% brake thermal efficiency; > 1 hp / lb power-to-weight; and the engine is targeted to fit within a 10”x10”x10” box weighing <40lbs. A first prototype engine “core” has been designed, analyzed, prototypes, and completed its initial testing.