Simulation of Admission and Exhaust Processes in Diesel Engines

Equations governing the flow through admission and exhaust ducts in diesel engines are presented taking into consideration the fluid compressibility, the variation of the duct cross section, and heat transfer and friction between the gases and the duct walls. The hyperbolic nature of the equations is shown and a solution is obtained using the method of the characteristics. The algorithm of this solution is included in a simulation model for a single cylinder diesel engine, based on the single zone combustion formulation. This model is used in a study to evaluate the engine performance indexes when different admission duct shapes are used.