Effect of valve timing events on the performance of compressed natural gas direct injection (CNGDI) engine using simulation

Abstract

The research for Compressed Natural Gas Direct Injection (CNGDI) vehicle has been explored recently. Through DI system there is an area that needs improvement on the performance outcome. The objective of this study is to investigate the influence of valve timing events on Compressed Natural Gas Direct Injection performance using 1-D simulation software. The CNGDI performance is analyzed for the converted petrol four stroke cycle, spark ignition port injection engine to CNGDI engine. The experimental on CNGDI engine is tested. The simulation model on CNGDI engine called the base model has been developed and correlated with the experimental result. By referring to the base model, the simulation model for the CNGDI is developed and calibrated. Through the CNGDI calibrated model, the valve opening and closing time on both valve has been adapted and compared with the performance result before and after the adjustment. The results are based on cylinder pressure, volumetric efficiency, engine torque and engine power with varied engine speed from 1000 to 6000rpm. The results showed better performance of CNGDI engine with less duration of valve timing events.