Conjugate Heat Transfer Analysis of a Fan-Shaped Film Cooled Concave Composite Plate

Abstract

In this paper, the thermal-flow field characteristics on film cooled concave composite plate with double-rows of fan-shaped staggered injection holes are discussed at different diffuse angles based on computational fluid dynamics and both adiabatic model and conjugate heat transfer model are considered. Governing equations adopted in this paper is steady-state Reynolds-averaged Navier-Stoke’s equations of steady state and turbulence model is two-equations standard κ-e model. To investigate the influences of hole configuration and blowing ratio on heat transfer distribution on the concave composite plate surface, four blowing ratios ranged from 0.5 to 2.0 and three diffuse angles of fan-shaped holes which are 8 o , 15 o and 21 o are tested. Simulation results show that the effect of blowing ratio on streamwise distribution of laterally-averaged film cooling effectiveness over the concave composite plate decreases monotonically in both adiabatic model and conjugate heat transfer model. At the same blowing ratio, film cooling effectiveness close to double-rows of jets increases as the diffuse angle increases, which indicates that diffuse angle design can intensify lateral jet flow on the concave surface. If the blowing ratio is higher than 1.0, none of the three diffuse-angle designs can avoid the lift-off phenomena of coolant jet flow. By further comparing the film cooling effectiveness distribution on the concave composite plate at the same blowing ratio between conjugate heat transfer model and adiabatic model, it is discovered that film cooling effectiveness at any position is higher in conjugate heat transfer model because it takes the internal cooling heat convection effect into consideration. Among the tested parameter combinations, area-averaged film cooling effectiveness is the highest when the diffuse angle of the fan-shaped jet hole is 21 o and the blowing ratio is 1.0.