采用热-流耦合方法对气冷涡轮叶片换热的计算

Numerical Study of Heat Transfer Using Heat-Flow Coupling Method for Turbine Blade with Air Cooling

以往在计算气冷涡轮叶片温度场时需要预先求出叶片和燃气交界面以及叶片和内冷气体交界面的对流换热系数,但是带有复杂内冷通道的叶片求解对流换热系数较困难,针对这一问题,采用了一种无需预先求出叶片表面对流换热系数的方法——热-流耦合方法,即只需给定主流流场的进出口边界条件和内冷通道边界条件以及叶片几何,就可求出叶片温度场的方法。文中采用热-流耦合方法首先对流体扰流前缘为钝形平板的二维层流流动进行了计算,计算结果与分析解进行对比,两者符合良好,证明了方法的可靠性,在此基础上对Mark涡轮叶片的换热问题进行了计算,计算结果与实验值吻合较好。说明热-流耦合方法在计算涡轮叶片换热问题时是有效可行的,具有很高的工程应用价值。

Aim.In China,we are among the first to employ heat-flow coupling method for numerically studying heat transfer in turbine blade with air cooling.In order to ascertain how effective this method is,we apply it in this paper to two numerical cases.This paper consists of two sections.The first section deals with a brief summary of the heat-flow coupling method. The second section deals with the two numerical cases in two subsections： 2-D laminar flow around a flat plate with blunt leading edge （subsection 2. 1） and heat transfer in Mark II turbine blade （subsection 2. 2）. In subsection 2. 1, the Nusseh numbers calculated with heat-flow coupling method are found to agree very well with the analytical solution given in Hermann Schlichting＇s book^[5] ;this shows that heat-flow coupling method is effective in solving conjugate heat transfer problem. In subsection 2.2, we calculate with heat-flow coupling method two temperature distributions and two pressure distributions in Mark II turbine blade, which we find agree respectively fairly well with the experimental temperature distributions and experimental pressure distributions given in Ref. 6 authored by L. D. Hyhon et ah The two cases show preliminarily that heatflow coupling method is feasible and effective.