汽车发动机涡轮增压器轴承体结构优化设计

Structure Optimization of Bearing Body Based on Numerical Simulation

轴承体作为涡轮增压器转子系统的关键零部件,冷却性能很大程度上决定了涡轮增压器的可靠性和使用寿命,而传统的涡轮增压器轴承体冷却系统设计往往以经验设计为主,导致冷却液流动性差,冷却效果不理想。优化针对涡轮增压器水冷轴承体存在的冷却水在水腔出口中间区域回转、影响其流速等问题,对水腔和机油腔进行了结构上的改进,同时以轴承体和冷却介质之间的传热原理为基础,用流固耦合的方法分别对改进前后两种轴承体结构进行数值仿真,得到改进前后水腔和油腔的温度场。通过对比发现:在相同的边界条件下,改进后冷却水和机油的温度降低,低温区域面积更加广泛。最后采用试验验证得出轴承体测温点的温度与仿真结果进行对比,表明数值仿真的精度较高,进而证明了改进后的轴承体冷却性能更加优异。

As a key component of turbocharger rotor system, the cooling performance of bearing body determines the reliability and service life of the turbocharger, while the traditional turbocharger bearing body cooling system is of- ten designed empirically, leading to poor fluidity of cooling fluid. Aiming to deal with the problems caused by the ro- tation of cooling water in water cavity of water cooled bearing body, this paper optimizes the structures of the water cavity and oil cavity in turbocharger. Based on the principle of heat transfer between the bearing body and the cooling medium, the study simulates the bearing body before and after the improvement by means of fluid - solid coupling, drawing a concise comparison between the improved temperature fields and the original ones. Through this compari- son, it is evident that under the same condition, the temperatures of water and oil in the improved bearing body are decreased, which accounts for a larger low temperature area. At last, by testing the temperature of the bearing body and contrasting it with the simulation result, this paper not only confirms the accuracy of the numerical simulation, but also further proves a better cooling performance of the improved bearing body.