The Effect of Impingement-Effusion Cooling Structure on Adiabatic Film Effectiveness

Abstract

Double wall cooling system for the vane is the most promising approach to meet the cooling demand of next generation turbine. The complex structure and heat and mass transfer process make many problems in double wall cooling unclear, which limits the development of double wall cooling in application. In this paper, the effect of impingement-effusion cooling structure on adiabatic film effectiveness is investigated numerically with two models, effusion film cooling-only and impingement-effusion cooling. Results show that the film effectiveness is not sensitive to the mass flow distribution of different rows of film hole and the effect of impingement structure on film effectiveness is very limited. It is therefore indicated that the film effectiveness of double wall cooling could be decoupled with complex heat transfer. It means the effect of impingement structure on adiabatic film effectiveness could be ignored when developing overall cooling models.