Analysis of numerical results for two-pass trapezoidal channel with different cooling configurations of trailing edge: The effect of dimples

Internal cooling of the gas turbine blades is imperative for the enhanced inlet temperature of gas turbine. In this paper, numerical results of two-pass trapezoidal channel provided with dimples for internal cooling of a gas turbine blade are discussed. Three configurations of dimples are compared and enhancement in heat transfer has been reported. Also pressure drop along the channel for all cases has been predicted. It is found that for the channel with inline arranged dimples having H/d ratio equal to 0.25, maximum heat transfer enhancement is attained. Staggered arrangement of the same dimples reduces pressure drop but also effects enhancement in heat transfer negatively. The thermal performance of the dimples size suggests that H/d ratio of dimples is an important parameter and its optimum value should be found out.