Turbine Nozzle Film Cooling Study Using the Pressure Sensitive Paint (PSP) Technique

Abstract

The use of pressure sensitive paint (PSP) to measure film cooling effectiveness on a turbine nozzle surface was demonstrated in a high speed wind tunnel. Film cooling effectiveness was measured from a single row of holes located on a turbine vane suction surface with a shaped exit. Nitrogen gas was used to simulate film cooling flow as well as a tracer gas to indicate oxygen concentration such that film effectiveness by the mass transfer analogy could be obtained. Three blowing ratios were studied for each of the five freestream conditions: a reference condition, a reduced and an increased Reynolds number condition, and a reduced and an increased Mach number condition. The freestream turbulence intensity was kept at 12.0% for all the tests. The PSP was calibrated at various temperatures and pressures to obtain better accuracy before being applied to the airfoil surface. The film effectiveness increased with blowing ratio for all the freestream conditions. The effects of secondary flow and freestream Mach number and Reynolds number on turbine nozzle suction surface film cooling are also discussed.

Development of an Experimental Test Facility for Investigating Mist/Air Film Cooling Application in Gas Turbine Airfoils

“…Another new mass transfer technique used to determine the adiabatic film cooling effectiveness uses the pressure sensitive paint (PSP) scheme. Zhang et al [29] first used this technique to determine the adiabatic film cooling effectiveness on a vane end wall, and it was shown that the strength of this technique lies in the absence of conduction effects.…”

Turbine Blade Cooling Studies at Texas A&M University: 1980-2004

“…Zhang et al 138 were the first research group using the PSP technique in a turbine nozzle film-cooling study. Ahn et al 139 presented film-cooling effectiveness results using the PSP technique on a plane and squealer blade tip with one row of holes on the camber line and another row of angled holes near the pressure-side tip.…”

Film cooling sensitivity of laidback fanshape holes to variations in exit configuration and mainstream turbulence intensity

“…[11][12][13][14][15][16]. Guo et al [11] found that fanshape holes produced higher cooling effectiveness and lower heat transfer coefficient than cylindrical holes on both suction and pressure side of a nozzle vane model in a transonic annular cascade.…”

“…Guo et al [11] found that fanshape holes produced higher cooling effectiveness and lower heat transfer coefficient than cylindrical holes on both suction and pressure side of a nozzle vane model in a transonic annular cascade. Zhang et al [12,13] investigated the influence of blowing ratio on the fanshape hole film cooling on a vane blade model. The results showed that when the blowing ratio was less than 1.5 the cooling effectiveness of fanshape holes increased with the increasing of blowing ratio.…”