涡轮叶片不同肋倾角交错肋冷却流动与传热研究

Numerical and Experimental Study on Flow and Heat Transfer Performance of Latticework Cooling Structures With Different Rib Angles

交错肋是航空发动机涡轮叶片的一种高性能内冷结构,为研究涡轮叶片内部交错肋冷却结构的流动和传热特性,针对30°、35°和45°三种肋倾角的交错肋结构进行了雷诺数在17000~70000之间的稳态传热实验和数值模拟研究。数值计算的有效性通过与实验结果进行对比得到充分验证。实验结果显示,在子通道个数和雷诺数均相同的情况下,平均Nu数和摩擦因子均随肋倾角的增大而增加;对比30°倾角的交错肋结构,45°倾角交错肋结构的平均Nu数增加了40.7%,摩擦因子增加了204.9%,综合传热性能提升了13.4%。数值计算结果显示,肋倾角的增大不仅增强了转向区域的冲击作用,而且加强了对侧子通道间的流动掺混,从而达到强化传热的效果。

Latticework structure is a high-performance internal cooling structure of the aeroengine turbine blade.To investigate the flow and heat transfer performance of the latticework cooling structure in turbine blades,the steady-state heat transfer experiment and numerical simulation were performed for five Reynolds numbers(17000≤Re≤70000)in latticework structures at 30°,35°,and 45°rib angles respectively.Numerical solutions were validated by the experimental results.The experimental results show that the average Nusselt number and friction factor all show development with the increase of the rib angle under the same condition.The average Nusselt number of the 45°latticework structure increases by 40.7%,the friction factor increases by 204.9%,and the thermal performance factor(TPF)increases by 13.4% compared with the 30°latticework structure.The numerical results indicate that the increase of the rib angle not only enhances the impingement effect of the turning region,but also strengthens the flow interaction between the opposed sub-channels,thus enhancing the heat transfer.