基于并行计算的二次喷射式HCCI汽油机的三维数值模拟

3D Numerical Simulation for Gasoline HCCI Engine with Two-Stage Injection Based on Parallel Computation

建立了缸内直喷HCCI汽油机带进、排气道的燃烧系统的三维工作过程循环数值模型,实现了HCCI发动机包括进气、压缩、燃烧、膨胀和排气工作过程的三维循环模拟并进行了验证。首先基于并行计算进行了不同当量比(负荷)工况下HCCI发动机缸内过程的对比分析,研究了负荷对HCCI发动机着火、燃烧和排放的影响。进而模拟了缸内直喷二次喷射的HCCI发动机循环工作过程,解析了HCCI发动机着火燃烧和排放过程,揭示了HCCI发动机缸内直喷二次喷射控制着火的规律。计算结果有助于对HCCI燃烧过程的深入理解,为HCCI发动机燃烧过程的优化提供了依据。

A 3-dimensional HCCI model taking into account of the intake port, the exhaust port and the combustion chamber was established for gasoline direct-injection HCCI engine cycle simulation. The working processes of HCCI engine was simulated and validated, including the intake, the compression, the expansion and the exhaust strokes. Based on the parallel computation, the incylinder processes of HCCI with different equivalence ratios were compared and analyzed, and the effects of load on the ignition, the combustion and the emissions of HCCI were studied. Furthermore, a 3D simulation of HCCI engine cycles with different two-stage direct-injection strategies were made to provide a detailed insight into the HCCI combustion and emissions. The principles of HCCI ignition control using two-stage injection were discussed. The results of this study provide the better understanding to the HCCI combustion process for gasoline direct-injection （GDI） engine and useful guide for combustion optimization of HCCI engine.