涡轮增压器轴向力变化规律试验与仿真

提出一种基于悬浮式设计的涡轮增压器轴向力测量方案，解决涡轮增压器轴向力测量范围窄和零点漂移问题，通过试验测量了增压器转子轴向载荷。进一步建立包含轮背间隙、密封环间隙的增压器压气机和涡轮仿真分析模型，基于试验结果验证模型的可靠性，并应用该模型研究揭示了增压器压轮和涡轮轴向力随工况的一般变化规律。研究结果表明：外吹状态时，在同一转速下增压器转子轴向力值随压气机端质量流量的减小而增大；自循环状态时，在转速低于额定转速时，增压器转子轴向力随转速的增加而增大，在转速高于额定转速时，增压器转子轴向力随转速的增加而减小；同一转速下，除喘振点附近，压气机轴向载荷随入口质量流量的减小而增大，涡轮轴向载荷随涡轮入口质量流量的增加而增大；压端和涡端轴向载荷最大的两个区域均为叶轮背盘和叶轮轮毂，且两区域轴向载荷方向相反。

Experimental and Simulation Study on Axial Force Variation of Turbocharger

A turbocharger axial force measurement scheme based on suspension design was proposed to solve the problems of narrow measuring range and zero drift in turbocharger axial force measurement, and experimentally measure the axial load of turbocharger rotor. Furthermore, a simulation analysis model of turbocharger compressor and turbine was established, including wheel back clearance and seal ring clearance, and the reliability of the model was verified based on the test results. The general variation of axial force of turbocharger compressor and turbine wheel with working conditions was revealed through this model. The results showed that: under the condition of external blowing, the axial force of the turbocharger rotor increases with the decrease of the mass flow rate of the compressor end at the same speed; in self-circulation state, at the speed lower than rated speed, the axial force of the turbocharger rotor increases as the speed increases, while at the speed greater than rated speed, the axial force of the turbocharger rotor decreases with the increasing speed; in addition, at the same speed, the axial load of the compressor increases with the decreasing inlet mass flow except around the surge point, the axial load of the turbine increases with the increasing mass flow rate at the turbine inlet; the two regions with the largest axial loads at the compressor end and turbine end are the impeller back disk and the impeller hub, and the directions of the axial loads in the two regions are opposite.