Development of High Efficiency Hybrid Cycle Rotary 'X' Engine

Alexander Shkolnik
LiquidPiston, Inc., Connecticut, United States

Keywords: combustion engine, rotary, diesel, thermodynamics

LiquidPiston has developed a new thermodynamic cycle which combines features of Otto, Diesel, Atkinson and Rankine cycles into a new High Efficiency Hybrid Cycle. The cycle features 1) high compression ration (Diesel); 2) Constant volume combustion (Otto); 3) over-expansion (Atkinson); and 4) Optional - steam addition (Rankine). This cycle achieves thermodynamic efficiency in excess of 75% with air standard assumptions, a significant increase over conventional Otto or Diesel cycles. The new cycle is embodied in a new type of Rotary Diesel internal combustion engine - similar at first glance to the Wankel Rotary engine, but flipped inside-out. The new architecture solves problems with prior rotary engines in sealing, lubrication, and durability, while the addition of the new thermodynamic cycle significantly increases the efficiency of the engine. The engine can be used for propulsion, or for power generation in a wide variety of heavy-fueled applications.