Experimental Investigation of Boundary Layer Separation With Heated Thin-Film Sensors

The heated thin-film method was adapted to meet the requirements of investigations on boundary layer behavior in a turbine rig. Special multisensor probes of vaporized nickel on a polyimide foil were developed and applied to the vanes. Basic experiments with an airfoil in a free stream were carried out and a reliable interpretation of the thin-film results was found by comparison with pressure distribution, flow visualization, and laser measurements. It can be shown that this measuring device is a suitable method for the investigation of separation bubbles and boundary layer transition.