增压直喷柴油机螺旋进气的三维模拟

Using 3-D Simulation to Investigate Turbo-Charged Helical Intake Process

用三维数值模拟的方法研究某四缸直喷柴油机实际增压条件下螺旋进气道的进气过程,并考虑了气体的可压缩性。分别对不同气门升程下气道中流场分布、流量系数以及涡流比的变化进行了分析。指出当进气速度大于当地音速时应对流量系数的计算值进行修正,并与稳态试验结果对比,结果吻合良好,为研究增压进气过程对性能与排放的影响提供了参考。

Using 3-D simulation to investigate the intake process of one real helical intake port under the different turbo-charged conditions, this paper analyzes the changes of micro structure, coefficients and swirl ratio of the intake port. The results are well agreement with the steady state experiment and the reason why the coefficient error is larger between calculation and experiment when the speed is larger than that of the local sound.And it is poisted out that the results need to be modified when the speed is more than that of the local speed of sound.And the paper also gives the valuable information for investigation the turbo-charged diesel engine's performance and emissions.