Optimization design of intake manifold and valve timing of gasoline engine based on AMESim code

In order to acquire lower fuel consumption and higher torque output at low and middle speed, an engine cycle simulation of a small turbocharged gasoline engine is conducted by AMESim code. After validated against test data, the simulation model is used to optimize the full load performance of spark ignition (SI) engine. The effects of both intake manifold length and valve timing on the torque, volumetric efficiency and fuel consumption are investigated in details. To overcome the conflicts between low speed and high speed engine performance, variable valve timing (VVT) strategy is also investigated. The results show that, engine torque and brake specific fuel consumption (BSFC) during low and middle speed period can be improved effectively as valve timing is optimized and matched with intake manifold length reasonably using the gas dynamic effect.