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To formulate a computer model for a two-stroke engine, the boundary conditions have to be solved for cylinder or crankcase to pipe flow, pipe flow to atmosphere. The models to deal with the former and the latter are often called partially open end model and open end model respectively. In this paper, two types of models for partially open end and two for open end are investigated by comparing the predicted pressure data in the exhaust pipe. Also, two different ways to model transfer pipe are considered. One treats the flow in transfer pipes as quasi-steady flow while the other simulates that with an one-dimensional gas dynamic model. The simulation is based on a zero-dimensional thermodynamic model for cylinder as well as crankcase and an one-dimesional gas dynamic model for pipes. The former uses 4th-order Runge-Kutta method and the latter uses a combined 4th-order Runge-Kutta and two-step Lax-Wendroff (4RK/2LW) method.

The significant fuel-economy gain that may be achieved from the application of ceramic materials to the piston engine technology requires practical and reliable exhaust heat recovery means. Such a means has so far eluded the engine technology community. The “add-on” bottoming cycles to the traditional piston engines based on Otto cycle and Diesel cycle are totally impractical. By contrast, steam injection has been effectively applied to gas turbine (electric generator) systems with significant increase in power output and thermal efficiency. The steam-injected gas turbine has been increasingly adopted in power production, and can be regarded as a mature technology. The question then arises as to whether steam injection can be used for piston-type engines in transportation. Gas generator engines-which have been investigated as experimental engines for many years-may be one of the piston-type engines ideally suited for practical heat recovery.