INVESTIGATING THE EFFECTIVENESS OF COOLING A SHELL-TYPE GAS-TURBINE BLADE WITH A THERMAL INSULATION COATING

The cooling of turbine blades with thermal insulating coating was investigated. A preliminary study was made to determine the effect of the coating thickness and material on the cooling effectiveness of the blade, which was followed by the investigation of the blade thermal state. The method of electrothermal analogy and an electric integrator were used in the investigation. The modeling was realized on a semilimited body representing a small element of the blade. Two coatings with different thermal conductivity, 0.2 mm and 0.4 mm thick, were studied. The experimental results were correlated by the mean integral temperatures on the coating surface, on the shell surface, and at a specified depth. The results showed the significant effect of the thermal conductivity on the blade temperature field. Standard blade specimens were subjected to mechanical tests. After tensile-strength tests, the specimens were inspected visually and electrically for cracks. (Author) Edited trans. of Energeticheskoe Mashinostroenie (USSR) n3 p92-99 1966, by H. Peck.