Numerical Calibration of Diesel Engine Variable Valve Timing

The performance of internal combustion engine can be improved by using variable valve timing technology. but how to get the optimal inlet/export valve open or close angles under various operating conditions still relies mainly on testing calibration method. By means of one-dimensional working process simulation method, the performance of a four cylinder diesel engine was simulated, and the influences of diffrent inlet/export valve timing on engine performances were compared. Optimum valve timing values and engine performances under thirty kinds of working conditions were gotton. After that, the engine performances compared with that without variable valve timing. Simulation results show that the engine performance, especially the emission performance, can be improved at all simulation working conditions. The method used in this paper may be a new way for calibration of optimal valve timing.