Multihole Cooling Film Effectiveness and Heat Transfer

Adiabatic film effectiveness and heat transfer measurements with injection of secondary air through arrays of holes in a flat plate into a turbulent boundary layer are presented. Measurements were taken both within and downstream of the multihole pattern for different hole pitch-to-diameter ratios and blowing rates. The hole configurations considered were regular patterns of staggered holes. The holes were angled 30 deg to the plate’s surface and 45 deg to the mainstream. A comparison between the measured adiabatic film effectiveness and a model based on the superposition of point heat sinks is made.