Free-Stream Turbulence Effects on Film Cooling With Shaped Holes

摘要: A comprehensive set of generic experiments has been conducted to investigate the effect elevated free-stream turbulence on film cooling performance shaped holes. row three cylindrical holes as a reference case, and two rows with expanded exits, fanshaped (expanded in lateral direction), laidback hole streamwise direction) have employed. With an external (hot gas) Mach number Ma m =0.3 operating conditions are varied terms intensity (up 11%), integral length scale at constant 3.5 inlet diameters), blowing ratio. The temperature ratio is fixed 0.59 leading enginelike density 1.7. results indicate that exhibit very different reactions levels. For effectiveness reduced increased level low ratios whereas small gain can be observed high ratios. holes, detrimental even for largest (M=2.5). In comparison impact varying found minor importance. Finally, heat transfer coefficients was much more pronounced