Experimental Study on Thermal Characteristics of Rotating Air Flow in Film Cooling Holes

 In this study, an increase in the inlet temperature of gas turbines through continuous conduction mechanisms to achieve high specific thrust and thermal efficiency has been investigated. The temperature has risen beyond the component melting point. In order to delay and suppress the deterioration of components, a technique called film cooling is generally applied. Membrane cooling refers to the cooling gas injected from the holes forming a film on the outer surface of the component to block direct contact of hot gases. In this study, we analyzed the heat transfer characteristics according to the shape of the cooling hole causing the vortex. IR cameras and T-type thermocouples are used in the test section with an emissivity of 0.95 to measure film cooling. The angle of injection with respect to the surface is 35 ° and proceeded for compound angles of 0 °, 90 °, and 180 °. Experimental results show that the vortex-causing hole has a difference in film cooling efficiency from that of the simple hole. The shape of the hole changes the flow of cooling gas and affects the cooling characteristics of the component. Experiments on the characteristics of heat transfer with changes in the shape of cooling holes are suggested as a reference for increasing the efficiency of gas turbines.