Supersonic film cooling effectiveness using air and helium for a range of injectant temperatures and Mach numbers

Experimental Studies of Film Cooling in Supersonic Combustors

“…Film cooling is a well-known method has widely used in rocket engines, aircraft, and it will be used in scramjet. 2 Studies of supersonic film cooling begin at 1960s. Goldstein et al experimentally studied supersonic film cooling with both air and helium as the coolant gas.…”

“…The results for helium injection indicate an increase in effectiveness as compared to that for air injection. 2 Kanda et al experimentally studied the supersonic film cooling with shockwave interaction, and found that the stronger shockwave with the pressure ratio of 1.44 decreased the effectiveness of the film cooling in the restricted region and the decrease of the effectiveness was mainly the result of the adiabatic temperature by the decrease of the local Mach number. 7 Wei Peng et al numerically studied the effect of coolant inlet conditions on supersonic film cooling and the results indicate that, for the same coolant gas without a shock wave or with a weak shock wave, the supersonic film cooling mainly depends on the coolant gas flow rate and has little relationship to the coolant inlet height or the Mach number.…”

Numerical simulation of supersonic film cooling in a rearward-facing slot

“…Bass et al 13 conducted experiments using hydrogen and nitrogen under different conditions and correlated their data in a single line with an empirical relationship. Hunt et al 14 and Juhany et al 15 measured the influence of injection Mach number and temperature and correlated the results using an empirical relationship; in contrast to previous studies, their work measured adiabatic wall temperature directly by insulating the wall. Hombsch and Olivier 16 conducted supersonic film cooling tests under laminar and turbulent supersonic flows and compared their results with other blowing slots.…”

“…When the original researches of supersonic film cooling were conducted, the film gas was mainly injected into the supersonic mainstream at sonic speed, including the experiments of Goldstein et al, 8 Parthasarathy and Zakkay, 9 Cary and Hefner, 10 and Richard and Stollery. 11 Later, the supersonic injection of film coolant into supersonic mainstream were becoming the focuses of the researchers, such as the works of Olsen et al, 12 Bass et al, 13 Hunt et al 14 and Juhany et al 15 Olsen et al 12 analyzed the effects of coolant feeding pressure, slot height, and lip thickness on film cooling. Bass et al 13 conducted experiments using hydrogen and nitrogen under different conditions and correlated their data in a single line with an empirical relationship.…”

Diode laser sensors for aeroengines - Lessons learned and future promises

“…This subsonic film was chosen because of the impracticality of velocity matching the film flow with the high velocity (~ 1km/s) main flow. Using film cooling design tools available in the literature [9][10][11][12] , we have selected a slot height of 2.3 mm and a film velocity of 130 m/s to hold the AR-coated window surface temperature below 450 K in the presence of free stream gas temperatures up to 2000 K.…”