Numerical Investigation of a SI-Engine Performance Equipped with a Variable Valve Timing System

Variable timing of valves is one of the effective factors on performance of a spark ignition (SI) engine. The time of opening, closing, duration of open state, and the amount of lift for inlet and exhaust valves are the parameters that must be considered in variable valve timing issue. These parameters influence thermodynamic performance factor and heat loss of an engine. In this paper at first, using K3PREP pre-processor, a structured moving mesh was generated for valves as well as for inner and outlet runners. Then, using KIVA-3V as the main solver, the variation effects of each valve timing parameters on the engine performance were studied. The simulation was done on a SI- engine. Comparison between simulation and experiment results indicates satisfactory agreement.