AN EXPERIMENTAL INVESTIGATION OF FILM COOLING EFFECTIVENESS ON LEADING EDGE OF TURBINE BLADE

Film cooling effectiveness of hole-rows on leading edge of turbine blade has been studied experimentally.The model is a blunt body with a half-cylinder leading edge and two flat side-walls.Six rows of round holes were ungradationally located at and from stagnation on the half-cylinder leading edge.The holes in each row were spaced three hole-diameters apart at angles to the surface spanwise and streamwise respectively.The length of hole is of four hole-diameters.Spanwise and streamwise distributions of film cooling effectiveness in the leading edge and on the flat side-wall were measured in the range of mainstream Reynolds number (based on leading edge diameter) from 42000 to 127000 and blowing ratio (average secondary to mainstream mass flux ratio) from 0.8 to 2.0.The results indicate that the film cooling effectiveness decreases with increasing blowing ratio but does not depend too much on the mainstream Reynolds number.The secondary flow locus is depedent on blowing ratio but also does not depend on mainstream Reynolds number too much.