Experimental Aspects of PIV Measurements of Transonic Flow Fields and their Benefit for the Optimization of Gas Turbines

Abstract

Reduction of fuel consumption and CO2 emission are two main objectives in gas turbine research. This can be achieved by further increasing operating temperatures. However, higher gas temperatures require new materials and/or internal cooling of turbine blades due to high mechanical loads in high pressure stages of gas turbines, trailing edges of turbine blades can not be built asdesired for reduction of viscous losses. The design of thin turbine blades is additionally complicated by the required integration of cooling flow. The wake of thick trailing edges causes significant losses especially in transonic flows. Knowledge of the interaction between the flow field around the trailing edge and the mass flow rate of the trailing edge ejection of cooling air is therefore of great importance. The goals of our investigations were: Determination of the structure of the wake and of the trailing edge shock system.