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采用三维数值求解方法,对透平叶栅端壁区域的流动和传热特性进行了研究.利用试验数据考核了相应的数值方法,分析了网格数目和湍流模型对叶栅端壁附近流动传热特性计算的影响,比较了不同进口雷诺数和湍流度条件下端壁传热特性的变化。结果表明;马蹄涡和通道涡等二次流动直接影响端壁区传热,传热强度分布规律基本与当地流动的湍动能保持一致。湍流模型对端壁压力场的计算影响较小,但对端壁传热特性的求解的精度影响较大。采用v~3—f湍流模型能较好地预测端壁传热分布。来流雷诺数和湍流度的变化改变了端壁边界层厚度和涡系结构,使得端壁传热强度和梯度分布发生变化。
The flow and heat transfer characteristics of the turbine blade cascade are studied by using the three-dimensional numerical method.The corresponding numerical methods are evaluated by the experimental data, and the effects of the number of grids and the turbulence model on the flow and heat transfer Thermal characteristics of the calculation of the impact of different import Reynolds number and turbulent flow conditions under the end wall heat transfer characteristics. The results show that the secondary flow, such as the horseshoe vortex and the passage vortex, directly affects the heat transfer in the end wall area, and the distribution of heat transfer intensity basically agrees with the turbulent kinetic energy of the local flow. The turbulence model has little effect on the calculation of the pressure field in the end wall, but has a great influence on the accuracy of the heat transfer characteristics of the end wall. The v ~ 3-f turbulence model can predict the heat transfer in the end wall well. Reynolds number and turbulent flow changes the thickness of the boundary wall and vortex structure, making the end wall heat transfer intensity and gradient distribution changes.