Experimental investigation of the aerodynamic and thermal behaviour of the film at the leading edge of a cooled nozzle vane cascade

This paper presents the results of an experimental investigation of the aerodynamic behavior of coolant ejection at the leading edge of a nozzle vane cascade. Highly spatially resolved Particle Image Velocimetry (PIV) data were acquired on mid span blade-to-blade planes and along the span wise direction to capture the 3D mixing process. Complementary Pressure Sensitive Paints (PSP) data are used to support the aerodynamic analysis. Tests were performed at a fixed cascade operating condition (Ma2is = 0.2 and Tu1 = 1.6%) varying the coolant to main stream blowing ratio (BR) from 2.0 up to 4.0. Flow filed data clearly show a shift in stagnation and a strong jet to jet as well as jet to mainstream interaction for all tested BR, supporting the unsteady and highly anisotropic nature of the phenomenon.