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为建立某型二冲程柴油航空发动机气缸内部三维扫气模型和缸内气相流动数学模型,并对气口结构进行分析,采用分块耦合方法和应用黏接技术对模型进行网格划分,使用GT-power获取仿真边界条件,利用Fluent软件对缸内气体流动进行三维数值模拟。研究结果表明:横流扫气在弱流动区域容易形成扫气盲点;回流扫气可以形成较好的径向涡流,但轴向涡流速度较低,降低扫气效率;混合扫气能减小扫气盲区,形成较好的螺旋涡和速度较高的轴向涡流,与回流、横流扫气相比,排气速度提高12.6%和125.2%,极大地提高了扫气效率。
In order to establish a 3D scavenging model and a mathematical model of gas flow in a cylinder of a two-stroke diesel engine, the structure of the gas port is analyzed. The model is meshed by the method of block coupling and the bonding technique. The GT- power To obtain the simulation boundary conditions, the three-dimensional numerical simulation of the gas flow in the cylinder was carried out by using Fluent software. The results show that the cross-flow scavenging is easy to form a scavenging blind spot in the weak flow area. The back-flow scavenging can form a better radial eddy, but the axial eddy velocity is lower, reducing the scavenging efficiency. The mixed scavenging can reduce the scavenging The blind zone formed a better spiral vortex and a higher axial vortex flow. Compared with the backflow and cross-flow scavenging, the exhaust speed increased by 12.6% and 125.2%, greatly improving the scavenging efficiency.