Effects of Free-Stream Turbulence and Wake Characteristics on the Heat Transfer Along a Cooled Gas Turbine Blade

Abstract

Heat transfer measurements under steady, quasi-steady and unsteady flow conditions are discussed. In continuing measurements on the influence of a plane steady wake flow as well as on the effects of grid-produced free-stream turbulence, the present paper describes the effects of the superposition of the free-stream turbulence with the wake flow. Of special interest is a comparison of the wake produced by a leading airfoil with that of a cylindrical bar in cross flow. The similarity of the wakes as far as macrostructure of the turbulence and velocity is concerned is documented using LDV and heat transfer measurements. In extending the modeling concept, a rotating wake generator is employed simulating the wake of a blade with cylindrical bars in cross flow. The comparison of the theoretical and experimental results is presented.