Investigation on heat transfer characteristics of trapezoidal channel with pin fins in rotating state

The flow and heat transfer characteristics of a typical cooling channel model in a turbine blade, namely, a rotating lateral outlet wedge channel with pin fins, were experimentally investigated. The Reynolds number range was 10000—80000 and the speed range was 0—1000 r/min. The rotation enhanced the heat transfer and the heat transfer enhancement was most obvious at the position of X/D=8.23 of inner area. When the Reynolds number was 10000, the average heat transfer at 1000 r/min was 211% higher than that at 100 r/min, and when the Reynolds number was 80000, it was 44.4% higher. At the outer area of channel, the heat transfer at each non-dimensional position increased slowly with the increase of rotating speed, and there was no significant difference in the heat transfer enhancement degree at different non-dimensional positions. At the same time, increasing Reynolds number could enhance the effect of rotation. When the speed was 1000 r/min, the heat transfer enhancement in the inner smooth area was most obvious at the position of X/D=3.97. At 80000 Reynolds number, the heat transfer coefficient at this point was 3.31 times that at 10000 Reynolds number. At the position of X/D=8.23, the heat transfer enhancement in the outer pin fin area was most obvious. The heat transfer enhancement at Reynolds number 80000 was 1.47 times that at Reynolds number 10000. The research supplemented the heat transfer in the tapered channel with pin fin at the trailing edge of turbine blade at high Reynolds number and high rotation number.