凹槽对涡轮叶片前缘换热特性影响的实验研究

In order to investigate the heat transfer characteristics of leading-edge of the turbine blade with groove shape, the influence of groove on the heat transfer coefficient of leading-edge is studied by using the transient thermochromic liquid crystal technology. The distribution data of heat transfer coefficient of original leading-edge structure and leading-edge structures with two different depth grooves are obtained under different mainstream Reynolds numbers and turbulence intensities. The heat transfer characteristics of three structures are evaluated by Nusselt number. The experimental results show that: the high heat transfer coefficient region exists in the original leading-edge structure, and the high heat transfer core area increases with the increase of turbulence intensity. Due to the influence of groove on the flow in the stagnation region, under different conditions, the leading edge structure with groove shows the distribution characteristics of dividing the high heat transfer core region of the original structure into high heat transfer regions on both sides of the groove and low heat transfer region inside the groove. The groove can significantly reduce the heat transfer intensity of leading edge surface, the average Nusselt number of the leading edge with shallow grooves is about 7.9%~14.5% lower than that of the original structure, and the average Nusselt number of the leading edge with deep grooves is about 9.1%~20.9% lower than that of the original structure. Compared with Re_g=2.0×10⁵, when Re_g=1.5×10⁵, the low heat transfer advantage of the groove structure is stronger than that of the original structure.