Heat Transfer Coefficient of Film Cooling with Ellipse-Shaped Tab

The enhanced cooling performance caused by ellipse-shaped tabs located at the outlet of the film cooling holes is conducted.Three covering ratios of ellipse-shaped tabs on film holes and four blowing ratios are studied.The results show that:(1)The heat transfer coefficient ratio is higher than that without tab,indicating that the mixing of mainstream and coolant jet provides a better coverage film on the cooling wall,but increases the local turbulence production which enhances the heat transfer coefficient;(2)When the ellipse-shaped tabs are located at the film hole outlet,there is a larger pressure drop with the ellipse tab relative to the no-tab case.Thus,the discharge coefficient with ellipse tab is lower than that without tab.