Numerical investigation on heat transfer performance of matrix cooling channels for turbine trailing edges

The paper investigated numerically the heat transfer and pressure loss characteristics of the converging matrix cooling channels for turbine trailing edges with response surface method. The three selected design factors are scale factor (SF), rib inclination angle (alpha) and channel wedge angle (beta). The discussed range for the design factors, SF, alpha and beta, are 2.5-10; 30 degrees-60 degrees and 1.5 degrees-2.5 degrees. And the investigated Reynolds number range is from 15,000 to 40,000. The turbulence model selected was SST k-omega model. It is newly found that the heat transfer and pressure loss characteristics of the converging matrix cooling channels depend heavily on the scaling effect. The matrix cooling channels with larger scale factor generally present higher heat transfer enhancement, higher pressure loss and lower overall thermal performance. In addition, the converging matrix cooling channels with smaller rib inclination angle and larger channel wedge angle present higher heat transfer enhancement and larger pressure loss. Among all the 13 cases, Case 9 with SF = 2.5, alpha = 45 degrees and beta = 1.5 degrees has the highest averaged thermal performance factor under 6 Reynolds numbers.