Abstract
This paper presents the performance of pressure-sensitive paint (PSP) for the direct measurement of species concentration on a porous surface with mass injection. It is used to measure the ability of an injected gas to reduce the mass transfer of freestream species to the surface. A porous alumina sample was sprayed with a PSP luminophore solution. The sample was installed into a flat plate model and exposed to hypersonic cross-flows in the Oxford High-Density Tunnel. Tests were conducted with no coolant injection, air injection, and nitrogen injection at increasing blowing ratios. Oxygen partial pressure maps on the transpiration-cooled surface were obtained for several conditions at unit Reynolds numbers between $$2.58{-}5.0 \times 10^7/ \mathrm{m}$$
2.58
-
5.0
×
10
7
/
m
and blowing ratios between $$0.016{-}0.078\%$$
0.016
-
0.078
%
. The oxygen pressure decreases as the unit Reynolds number decreases and the blowing ratio increases.
Graphic abstract
Pressure-sensitive paint diagnostic to measure species concentration on transpiration-cooled walls
