Experimental study of free-stream turbulence intensity effect on overall cooling performances and solid thermal deformations of vane laminated end-walls with various internal pin–fin configurations

Abstract

Experimental investigations of mainstream turbulence intensity (Tu) effect on conjugate heat transfer performances, total pressure loss and solid thermal deformations of vane laminated cooling end-walls (LCEs) have been carried out under two engine-near mainstream-to-coolant temperature ratios of 1.4 and 2.0. Influences of parameters of internal elements of LCEs were discussed. A servicing film cooling end-wall (FCE) was chosen as a reference. Two typical Tus were designed, 2.2% and 10.1% (in the engine range). Measurements of fluid-thermal-solid coupling characteristics of cooled end-walls were implemented in a hot wind tunnel based on matched engine Biot number under three mass flow ratios. Generally, the elevated Tu exhibited a negative influence on overall cooling effectiveness and component reliability of cooled end-walls, total pressure loss in cascade and slight thermal deformations of LCEs. Moreover, the elevated Tu displayed a negative effect on the remarkable benefit of LCEs over FCE. The shape and diameter of pin-fins and the impingement-hole size played complex roles on overall effectiveness, surface thermal gradient, aerodynamic loss and component weight. However, the Tu effect on the aforementioned roles was slight. Overall, the LCE with diamond-shaped pin-fins and large impingement-holes was the most optimal design.