PIV Technology for Simulated Turbine Film-Cooling Flows.

Abstract : Two-color double-pulsed PIV(Particle Image Velocimetry) was used to investigate turbine film-cooling flows with high freestream turbulence and simulated wake passing. Since the instantaneous realizations of these highly turbulent and unsteady flows are not representative of mean flow behavior, 10 - 30 realizations were typically recorded. The average from these realizations of the film-cooling flows for 1% freestream turbulence was compared with the corresponding hot-wire profile. The PIV images revealed shear-layer structure developing from the film-cooling-hole walls that has not been previously considered in modeling these flows. Improved modeling of the fluid dynamics of interaction and development of these flows (jet-spread and turning) also resulted from this PIV technique. Two-color double-pulsed PW (Particle Image Velocimetry) was used to investigate turbine film-cooling flows with high freestream turbulence and simulated wake passing. Since the instantaneous realizations of these highly turbulent and unsteady flows are not representative of mean flow behavior, 10 - 30 realizations were typically recorded. The average from these realizations of the film-cooling flows for 1% freestream turbulence was compared with the corresponding hot-wire profile. The PW images revealed shear-layer structure developing from the film-cooling-hole walls that has not been previously considered in modeling these flows. Improved modeling of the fluid dynamics of interaction and development of these flows (jet-spread and turning) also resulted from this PIV technique.