Internal heat transfer performance of rotating and trapezoidal trailing edge channels with dimple structure

Developing efficient trailing edge cooling technology is essential for the safe and stable operation of turbine blades. As a kind of depressed turbulator, dimples can effectively enhance the heat transfer while producing less flow resistance, thus has broad application prospects in the internal cooling of turbine blades. In this paper, trapezoidal trailing edge channels with lateral slots and dimples are modeled and numerical calculations are carried out to investigate the flow characteristics, wall heat transfer distributions and the overall heat transfer performance under rotating state. Effects of dimple arrangement, rotation number and channel orientation on the internal cooling performance are comprehensively analyzed. The results show that the dimple greatly improves the heat transfer level of rotating cooling channels. In the dimple channels, a 108.2% improvement in the Nu/Nu0 of trailing surface can be achieved by increasing the rotation number. Compared with the rotation number, the channel orientation has stronger influences on the trailing edge cooling performance, thus should be emphatically considered in practical applications. This research has important guidance significance for the cooling design of trailing edge in gas turbine rotor blades.