车用涡轮增压器轴向气动作用力分析

Analysis of Axial Aerodynamic Force of Vehicle Turbocharger

针对涡轮增压器高转速工况下止推轴承损坏的现象,以某涡轮增压器为研究对象,分析涡轮增压器轴向气动力随不同工况的变化。建立包含轮背间隙、密封环间隙的增压器压气机与涡轮三维模型,在ANSYS/ICEM中进行网格划分,采用ANSYS/CFX求解器对不同工况下增压器压气机、涡轮的流场进行数值仿真。计算结果表明:随着转速增加,涡轮增压器轴向力合力增大,并且与理论值偏差增大;同一转速下,密封环间隙对于轴向力合力影响较小,而且小密封环间隙气体泄漏量小;同一转速下,随着流量的增加,增压器轴向合力随之减小。

Aiming at the phenomenon that the thrust bearing of the turbocharger was damaged at high rotational speed,the turbocharger was researched to analyze the variation of the axial force with the different working conditions.The models of turbocharger compressor and turbine,including wheel gap and seal ring clearance,were constructed.Then ANSYS-ICEM was used to mesh grid and ANSYS-CFX was used simulate the flow field of turbocharger compressor and turbine with the different working conditions.The results show that the axial force of turbocharger increases with the rotating speed increasing and the deviation from the theoretical value increases.Keeping the rotating speed constant,the effect on axial force of seal ring clearance is not obviously but the leakage is low with the tight seal ring clearance;the axial force will decrease with the flow increases.