基于数值模拟的机车柴油机喷油嘴的结构优化

Structural optimization of injection nozzle for locomotive engine based on numerical simulation

为了改进16V280ZJ型柴油机的性能,对其喷油嘴内的流场进行三维数值模拟,得到了在不同压力条件下详细的流场结构。通过流场分析可知,随着喷射压力的提高,流场湍流强度增大,湍流引起的能量损失增加,流量系数降低。并应用CAD/CAM/CFD集成的方法对喷油嘴结构进行优化,找到了喷油嘴内存在的不合理部位,将喷油嘴结构改为球形针阀后,在同等喷射压力下能够大幅度提高喷油流量。

In order to improve the performance of 16V280ZJ diesel engine,the three dimensional numerical simulation of flow field in nozzle was made,and the detailed flow field structure under different pressure conditions were obtained.Through the flow field analysis,it is shown that with the increase in injection pressure,the turbulence in flow field was increased,energy loss caused by turbulence was increased,and the flow coefficient was decreased.By using CAD/CAM/CFD integrated method,the structure of nozzle was optimized.After the nozzle sturcture has been changed with spherical needle,the fuel injection rate can be greatly increased at same injection pressure.