Analytical and Experimental Investigation of Flow Through a Turbine Vane Cascade .

Abstract

Present day military aero-gas turbines demand higher stage loadings for turbines so as to meet the growing for higher thrust/power with fuel consumption. This calls for improved methods of blade element profiles. Details of a computer code developed for the design of blade elements for the prescribed distribution of surface velocity (Mach number) based on Stanitz's inverse methods are presented in this paper. Effects of boundary layer growth on the blade surface has also been incorporated in this code. Turbine vane was designed making use of this program and a four-bladed cascade was fabricated. It was tested in a blow down wind tunnel for different blowing pressures and stagger angles. Mach number distribution was determined from measured static pressure on the suction and pressure surfaces of the blade. Based on stream filament technique a computer code was developed to predict the characteristics of flow thorough a blade cascade. Results of this study show reasonable agreement between experimentally obtained Mach number distribution and the initially prescribed as well as analytically predicted Mach number distributions.