Petelchyts V. Development of film cooling systems of gas turbine blade leading edge.

The thesis is aimed at the study of gas turbine blade leading edge film cooling, formed by coolant supply through three-row cylindrical hole systems, with radially arranged and with parallel to each other hole rows. Besides, there were studied three-row variants with fan-shaped holes, and holes, located in hemispherical dimples and embedded in trenches. Three variants of radial hole row systems with different row angles to the stagnation line (а = 15, 30 and 45) were considered; the influence of this angle on the film cooling efficiency for the leading edge and following flat wall was determined. It was found, that for the radial hole row systems, the highest film cooling effectiveness provides the scheme with а = 15. It was revealed, that the system of three parallel hole rows was more efficient in comparison with radial hole row systems. Investigations on film cooling effectiveness in cases with fan-shaped holes, holes in hemispherical dimples and holes, embedded in trenches on the leading edge, showed, that in contrast to the flat plate, film cooling efficiency augmentation was obtained only for system of holes embedded in trenches. In this work flow patterns, the effect of wall curvature, velocity and static pressure gradients in inter blade passage conditions on film cooling effectiveness distribution for the radial row systems were also studied.