Simulation and Optimization on Combustion Characteristics of Linear Engine System in Starting and Idle Process

Abstract:

The primary goal of this research is to build an engine simulation model through GT Power to study the combustion characteristics of linear engine system in starting and idle process. The cylinder pressure data collected from engine experiment were used to verify the simulation model. Based on this simulation model, the influence of the excess air coefficient and ignition advance angle on combustion characteristics of the linear engine system in constant revolution was studied and the control parameter in idle process was optimized. The results show that the ignition time being advanced from -50°(before the top dead center) to 20°under a constant excess air coefficient, the cylinder pressure, the instantaneous heat release rate and the total heat release all reach their largest peak value when the ignition advance angle is -40°. Reducing the excess air ratio from 1.62 to 0.62 under a constant ignition advance angle, the cylinder pressure and the instantaneous heat release rate all reach their largest peak value and the total heat release is large when the excess air ratio is 0.83.

Key words:linear engine; simulation; GT Power; combustion characteristics