Study On Simulation And Test Of GW4C20Gasoline Engine Operating Process

This paper is based on GWM4C20engine, and in order to improve its performance by optimizing intake and exhaust systems, research is carried out on turbocharged direct injection gasoline engine, in order to support engine advanced process and to offer schemes.Output performance target was set after having research and analysis at home and abroad. Following the benchmark engine cycle simulation was carried out by1-D software boost and CFD tool fire.Simulation flows was found for how to optimize valve lift,and analyze how it impact engine performance.Finally compromise on residual gas in cylinder of idle speed,maximum movement of cam phase,valves will not impact cylinder was made and valve timing was decided.In order to get better output and economy performance,research on manifold diameter, length, volume and structure type were carried out by CFD and1-D gas exchange analysis.The results and reason were analyzed in detail.Length of intake manifold have more than11%influence on engine performance; Intake manifold diameter has a relatively small influence on engine performance, only2.1%; Volume of intake manifold has little influence. For design of exhaust manifold much eyes were put on the room lay.The type of4-2-1exhaust manifold was chosen based on room lay of turbocharger and flow uniformity must higher than3%.The simulation results shows that GW4C20can reach its output power to157kW at rated speed5500rpm.At speed1800rpm it can only reach to308Nm, and320Nm at speed2800rpm.At last comparisons were made between simulation results and test dates,including power output,fuel consumption,temperature and pressure of measuring points,the difference is between3.8%-9.1%, and last we have choosed the case of small valve overlap because of the stability of idle speed. In consider of power output and fuel economy the design target has been reached.