The present paper is designed to investigate how the longitudinal vortex imbedded in a turbulent boundary layer interacts with the film injectant flow and also to provide useful data such as the local adiabatic film cooling effectiveness and heat transfer coefficient. The embedded vortex is generated by a delta wing installed upstream of injection holes. The injection holes have a 15° forward expansion with an inclination angle of 35°. Employed is a single row of seven injection holes, which are spaced 3 hole diameters apart in the spanwise direction. The blowing ratios considered are 0.5 and 2.0. The effect of the relative position of the vortex with respect to the film injection hole is also investigated on the heat transfer coefficient and adiabatic effectiveness distributions. It has been found that the film-cooling performance is affected highly by the presence of embedded vortex. The local adiabatic effectiveness and heat transfer coefficient distributions vary remarkably according to the relative positions of the vortices. At a low blowing ratio, film-cooling performance is swayed by the film coverage or adiabatic effectiveness distribution rather than the heat transfer rate. At a high blowing ratio, the film cooling performance is dominated by the heat transfer coefficient distribution.
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