APPLICATION OF PRESSURE AND TEMPERATURE SENSITIVE PAINTS ON A HIGHLY LOADED TURBINE GUIDE VANE IN A TRANSONIC LINEAR CASCADE

Abstract

The transonic flow characteristics of highly loaded turbine guide vanes are complex. A typical transonic flow field deals with steady and unsteady shocks, separation bubbles and trailing edge shocks. This leads to further investigation of the shock waveboundary layer interaction. To get a more detailed understanding of the flow field a spatial pressure and temperature resolution on the blade surface is required. Initially, steady response pressure (PSP) and temperature (TSP) sensitive paints were applied to the suction side surface of a turbine guide vane in a transonic linear cascade (EGG) at DLR Göttingen. The qualitative and quantitative results agree well with results from Schlieren images and pressure taps taken in the same measurement campaign. Subsequently, fast response Pressure Sensitive Paint (iPSP) was applied to the suction side of the guide vane. The qualitative data sets from the iPSP measurement are able to visualize unsteady flow characteristics in the cascade up to 1 kHz. Averaged iPSP results agree well with the pressure taps measurements taken at same conditions. During this test campaign different flow characteristics including shocks, separation bubbles and laminar to turbulent boundary layer transition have been identified for different Mach numbers.