LiquidPiston signs $1M agreement with DARPA to advance development of power-dense X-Mini rotary engine for JP-8
LiquidPiston, Inc. (LPI), the developer of engines based on its High Efficiency Hybrid Cycle (HEHC) (earlier post), has entered into an agreement totaling $991,557 with the US Defense Advanced Research Projects Agency (DARPA) to advance the development of its efficient, power-dense rotary internal combustion engine X-Mini (earlier post) for portable and small-engine applications.
Under this agreement, LiquidPiston’s primary objective is to demonstrate a pathway towards a rotary JP-8 fueled engine that has the potential to reduce fuel consumption by 50% and to increase power density by threefold compared to today’s conventional heavy-fuel piston engines. JP-8, or Jet Propellant 8, is a kerosene-based jet fuel used widely by the US military.
Today’s diesel/JP-8 engines and generators are extremely heavy. For example, a typical 3kW heavy-fuel generator weighs over 300 pounds, requiring six people to move it around. LiquidPiston’s engine technology may enable a JP-8 generator of similar output weighing less than 30 pounds that could fit in a backpack.—Dr. Nikolay Shkolnik, LiquidPiston’s Founder and CTO, and Co-Principal Investigator of the DARPA project
The ultimate goal of the funded effort is to demonstrate a pathway to a heavy-fueled engine that could deliver above 50% average brake efficiency, 57% peak brake efficiency and high power density (>1 hp/lb), using a test-bed environment.
Such efficiency would reduce fuel consumption by approximately one half compared to today’s conventional piston engines. The effort will demonstrate key enabling components of the engine technology, as well as initial experiments with JP-8 fuel. As part of the agreement, LiquidPiston is investing 40% of the project costs.
Early LiquidPiston prototypes have validated the principles and confirmed compression ignition of diesel and JP-8 fuels. LiquidPiston has built 70-horsepower and 40-horsepower compression ignition heavy-fuel engine alpha prototypes, and recently unveiled a 70-cubic centimeter (3- to 5-horsepower) gasoline powered rotary four-stroke engine prototype, which would serve as the test platform for the work with DARPA.
HEHC. HEHC is an improved thermodynamic cycle optimized for fuel efficiency that combines features of four existing cycles: high compression ratio (Diesel); constant volume (isochoric) combustion (Otto); over-expansion to atmospheric pressure (Atkinson); and internal cooling with air or water (Rankine).
LiquidPiston’s engines, have only two primary moving parts—a shaft and rotor—resulting in compact size and low-vibration operation. Although they are rotary engines, LiquidPiston’s engines are not Wankel engines; they are uniquely configured to adopt the company’s patented thermodynamic cycle and its associated efficiency and low-noise benefits.