Experimental and Numerical Study of the Turbulent Flow and Heat Transfer in a Wedge-Shaped Channel With Guiding Pin Fin Arrays Under Rotating Conditions

Abstract

Experiments and numerical simulations under stationary and rotating conditions have been conducted to investigate turbulent flow and heat transfer characteristics of innovative guiding pin fin arrays in a wedge-shaped channel, which models the internal cooling passages for modern gas turbine blade trailing edge. The Reynolds number range is 10,000–80,000, and the inlet rotation number range is 0–0.46. With the increase of Reynolds number, the enhancement of heat transfer performance of the channel with guiding pin fin arrays is significantly higher than that of the channel with conventional circular pin fin arrays. At the highest Reynolds number of Re = 80,000, the overall Nusselt number of the channel with guiding pin fin arrays is about 33.7% higher than that of the channel with circular pin fin arrays under the stationary condition and is about 23.0% higher than the latter under the rotating conditions. At the highest inlet rotation number of Ro = 0.46, the heat transfer difference between the trailing side and leading side of the channel is significantly lower with the guiding pin fin arrays than with the circular pin fin arrays. Through both the experiments and numerical simulations, it is found that the heat transfer uniformity of the endwall is significantly improved by the guiding pin fin arrays, and the rotation presents appreciably less influence on the heat transfer distribution with the guiding pin fin arrays than with the circular pin fin arrays. Moreover, the novel guiding pin fins provide more reasonable flow distribution in the wedge-shaped channel and produce obviously higher heat transfer performance in the tip region of the channel, which is significantly advantageous for a better design of gas turbine blade trailing edge internal cooling.