A Preliminary Numerical Study on the Effect of High Freestream Turbulence on Anti-Vortex Film Cooling Design at High Blowing Ratio

Researchers at NASA Glenn Research Center have developed and investigated a novel film cooling design, the anti-vortex hole (AVH), which has been shown to cancel or counter the vorticity generated by conventional holes and increase film effectiveness at high blowing ratios and low turbulence levels. This paper presents preliminary CFD results on the film effectiveness and net heat flux reduction at high blowing ratio and elevated freestream turbulence levels for the adjacent AVH. Baseline cases at low turbulence levels of 5% intensity and length scale of Λx /dm = 1 with a nominal blowing ratio of 2 and a density ratios of 1 and 2 were compared to previous results reported by Heidmann [1]. Higher freestream turbulence cases were investigated with a turbulence intensity and length scale of 10% and Λx /dm = 1 and 3, respectively. Results showed that higher freestream turbulence improves adiabatic effectiveness for the AVH design.Copyright © 2010 by ASME