具有柱肋阵列与分离式柱肋阵列的冷却通道内流阻与传热实验研究

Experimental Study of Flow and Heat Transfer in Cooling Channels with Pin Fin Arrays and Detached Pin Fin Arrays

在常规柱肋阵列冷却结构的基础上对一种新型分离式柱肋阵列冷却结构内的流动和传热特征进行了实验和数值计算研究.在雷诺数Re=8 200-50 500时,对具有新型分离式柱肋阵列的冷却通道和具有常规柱肋阵列的冷却通道内传热和流动压力损失性能进行了对比实验研究.对2种通道内的流动与传热进行了三维稳态数值计算,对比研究了其各自的速度场和局部传热特性,揭示了分离式柱肋阵列强化传热以及降低流动阻力的机理.实验结果表明,在所研究的Re范围内,与常规柱肋阵列通道相比,新型分离式柱肋阵列通道具有更高的平均努塞尔数（Nu）以及更小的阻力损失.

Pin fin array is a commonly used cooling structure in a gas turbine blade. Based upon the conventional pin fin cooling structure, this paper proposed a novel cooling structure with detached pin fin arrays. In the Reynolds number range of 8 200 to 50 500, a comparative experimental study was conducted to obtain the pressure loss and heat transfer characteristics in the cooling channels with detached pin fin arrays and with conventional pin fin arrays respectively. The results indicated that, compared to the counterpart of the pin fin channel, the detached pin fin channel has higher average Nusselt numbers and significantly reduced pressure loss over the studied Reynolds number range. Moreover, three-dimensional conjugate computations were carried out for similar experimental conditions, and the computations showed the detailed characteristics in the distribution of the velocity and turbulence level in the flow, which revealed the underlying mechanisms for the associated pressure loss reduction and heat transfer enhancements in the channels with detached pin-fin arrays.