基于CFD的机械增压器进、排气口的结构优化

Structure optimization of inlet/outlet of supercharger based on CFD

排气稳定性是双螺杆机械增压器的一项重要性能指标,文中基于CFD研究双螺杆机械增压器进、排气口处倒圆角对排气口处流场的影响,以3-5齿单边不对称摆线-销齿圆弧型线为例,建立转子型线数学模型,并以此为基础建立转子的二维模型,利用FLUENT动网格技术对双螺杆机械增压器的工作过程进行动态仿真模拟。计算结果表明,仅排气口处倒圆角即可以有效提高排气口处流场的稳定性。利用仿真结果预测排气口流场的变化情况,为增压器的结构优化设计提供参考依据。

The exhaust stability of twin-screw supercharger was an important performance index. This paper studied the effects of the fillets at the inlet/outlet of the twin-screw supercharger to the flow field at the outlet based on FLUENT Computational Fluid Dynamics（CFD）. Taking the case of a 3-5 unilateral asymmetric cycloid-pin tooth arc line, a mathematical model of rotor was built and a two-dimensional geometric model of rotor was built based on this. The dynamic simulation of twin-screw supercharger work process was performed through the dynamic mesh technology of FLUENT CFD software. The results showed that only outlets fillets could improve the stability of flow field at the outlet. This could predict the changes of flow field at the outlet according to the simulation result, which provided the reference for the structural optimization of the supercharger.