Film Cooling and Heat Transfer in Nozzles

In this paper experimental and theoretical investigations on heat transfer and cooling film stability in a convergent–divergent nozzle are presented. Compressed air is injected into hot air in the inlet region of the nozzle and the influence of the strong favorable pressure gradient in the nozzle on turbulent heat transfer and mixing is examined. The experiments cover measurements of wall pressures, wall temperature, and wall heat flux. Calculations with parabolic finite difference boundary layer code have been performed using a well-known k–ε-turbulence model with an extension paying regard to acceleration. As a result the calculated wall heat flux is compared with the measured heat flux.