Bezliudna M. Film cooling efficiency at the coolant supply through the double-row of holes arranged in surface hemispherical dimples.

The thesis is associated with experimental and theoretical study of the film cooling fundamentals on a flat plate with double-row of round inclined holes located in hemispherical dimples in front of the flat plate. The new correlation is given for the free-stream turbulent flow with low external turbulence, the effects of external turbulence and flow acceleration were studied and relative functions describing influence of these factors were obtained. The comparative analysis was made both for the studied in this work and traditional cooling schemes with coolant injection through the double-row of round inclined holes.Also, the coolant injection through the studied configuration demonstrates more uniform coolant distribution in the span-wise direction compared to the traditional cooling scheme. The comparison with other novel cooling schemes has shown the double-row scheme with holes in hemispherical dimples is not worse than advanced film cooling scheme with "fan-shaped" holes with more complex manufacturing technology. The analysis of six RANS turbulence models was provided for the free-stream flow with low external turbulence, the accelerated flow and the external turbulence. The results of the computer simulation and surface flow visualization have shown that primary reasons of the film cooling efficiency growth are reduction in the coolant jets separation and decrease in the "kidney" vortex intensity in the area after the secondary flow supply.