Total-System Simulation Model of Two-Stroke Cycle, Crank Case Compression-Type, Spark Ignition Engines

Because scavenging and exhaust flows strongly relate with the combustion process in two-stroke cycle engines, it is necessary to develop a total-system simulation model as a design tool of these engines. The model proposed in this paper consists of four essential elemental models which are non-steady flow in both the transfer and exhaust pipes, change of state in the gas of the crank case, the reed valve characteristic and change of state in the engine cylinder. The calculated results show that the model is useful in understanding the history of pressure, temperature and flow rate in the engine with changing specifications and operating conditions of the engine. It is confirmed that the computing time is reasonably short and this model is useful as a design tool for two-stroke engines.