Aero-Thermal Calculations for a Rotor Blade With Different Dimple and Protrusion Arrangements

Abstract This article presents an investigation of dimples and protrusions arranged on the end wall of a rotor blade to enhance heat transfer. This study explores three arrangements of dimples and protrusions relative to the pin-fins, specifically positioned near the leading edge (D1 and P1), between two adjacent pin-fins (D2 and P2), and near the trailing edge of the pin-fins (D3 and P3). Each arrangement is further characterized by two depth ratios, with the depths being 0.1 and 0.3 times the diameter of the pin-fins, respectively. The SSTγ–θ turbulence model is used to numerically simulate the results of flow and heat transfer characteristics, and the effects of dimples and protrusions on the heat transfer enhancement are analyzed. The following results are shown: the arrangement of dimples and protrusions on the end wall of the pin-fin cooling channel can effectively improve the heat transfer effect, and the effects of different arrangements of dimples and protrusions on the horseshoe vortex of the pin-fin are obviously different. Therefore, there are also significant differences in the cooling effect on the blade. The average temperature of the pressure surface decreases by about 8.3 K with the D2_0.1 arrangement, but the maximum surface temperature increases slightly. For the P3_0.3 arrangement, the average temperature decreases by about 4.1 K, and the maximum surface temperature decreases by nearly 36 K.