排气涡轮基于顺序流固耦合传热数值模拟研究

Numerical Simulation Research of Sequential Fluid-solid Coupling Heat Transfer of Exhaust Turbine

针对某四缸发动机涡轮增压器排气涡轮在高温及废气气动载荷、离心载荷下的综合数值模拟研究,该数值模拟联合计算流体动力学和有限元分析进行顺序流固耦合传热分析。首先利用STAR CCM+精确模拟计算涡轮增压器排气涡轮的温度场、表面压力场、壁面传热系数分布,将其作为第三类边界条件和压力载荷映射到排气涡轮有限元模型上。通过ABAQUS进行稳态热传导数值模拟,计算出排气涡轮有限元模型网格所有节点的温度场和表面温度,将计算所得的温度场作为预定义场进行热应力分析,最后结合气动载荷和离心载荷进行综合应力分析。

For a four-cylinder engine＇s turbocharger exhaust turbine, the comprehensive numerical simulation research is performed under high temperature, exhaust-gas aerodynamic load and centrifugal load. In the numerical simulation, computational fluid dynamics and finite element analysis is used to analyze sequential fluid-solid coupling heat transfer. First, the temperature field, the surface pressure field and the boundary heat transfer coefficient distribution are simulated and computed accurately by means of STAR CCM＋. These are considered as the third boundary condition and pressure load, which are mapped to the finite element model of the exhaust turbine. The steady-state heat conduction numerical simulation is carried out through ABAQUS to calculate the temperature field and surface temperature of all nodes on the turbine＇s finite element model grid, and the calculated temperature field is taken as the pre-defined field to implement thermal-stress analysis. Finally aerodynamic load is combined with centrifugal load to perform compound stress analysis.