Mathematical modeling and analysis of gas torque in twin-rotor piston engine
来源期刊：中南大学学报(英文版)2013年第12期
论文作者：DENG Hao(邓豪) PAN Cun-yun(潘存云) XU Xiao-jun(徐小军) ZHANG Xiang(张湘)
文章页码：3536 - 3544
Key words：rotor; piston engine; gas torque; power density; adiabatic process
Abstract: The gas torque in a twin-rotor piston engine (TRPE) was modeled using adiabatic approximation with instantaneous combustion. The first prototype of TRPE was manufactured. This prototype is intended for high power density engines and can produce 36 power strokes per shaft revolution. Compared with the conventional engines, the vector sum of combustion gas forces acting on each rotor piston in TRPE is a pure torque, and the combustion gas rotates the rotors while compresses the gas in the compression chamber at the same time. Mathematical modeling of gas force transmission was built. Expression for gas torque on each rotor was derived. Different variation patterns of the volume change of working chamber were introduced. The analytical and numerical results is presented to demonstrate the main characteristics of gas torque. The results show that the value of gas torque in TRPE falls to be less than zero before the combustion phase is finished; the time for one stroke is 30° in terms of the rotating angle of the output shaft; gas torque in one complete revolution of the output shaft has a period which is equal to 60° and it is necessary to put off the moment when gas torque becomes zero in order to export the maximum energy.
DENG Hao(邓豪)1, 2, PAN Cun-yun(潘存云)1, XU Xiao-jun(徐小军)1, ZHANG Xiang(张湘)1
(1. College of Mechatronic Engineering and Automation, National University of Defense Technology,
Changsha 410073, China;
2. Naval Aeronautical Engineering Institute, Qingdao Branch, Qingdao 266041, China)
Abstract:The gas torque in a twin-rotor piston engine (TRPE) was modeled using adiabatic approximation with instantaneous combustion. The first prototype of TRPE was manufactured. This prototype is intended for high power density engines and can produce 36 power strokes per shaft revolution. Compared with the conventional engines, the vector sum of combustion gas forces acting on each rotor piston in TRPE is a pure torque, and the combustion gas rotates the rotors while compresses the gas in the compression chamber at the same time. Mathematical modeling of gas force transmission was built. Expression for gas torque on each rotor was derived. Different variation patterns of the volume change of working chamber were introduced. The analytical and numerical results is presented to demonstrate the main characteristics of gas torque. The results show that the value of gas torque in TRPE falls to be less than zero before the combustion phase is finished; the time for one stroke is 30° in terms of the rotating angle of the output shaft; gas torque in one complete revolution of the output shaft has a period which is equal to 60° and it is necessary to put off the moment when gas torque becomes zero in order to export the maximum energy.
Key words:rotor; piston engine; gas torque; power density; adiabatic process
