Research Progress on Effects of Gas Film Pore Geometry on Mechanical Properties of Turbine Blades

Air film holes are widely used in turbine blades due to their excellent cooling effect. The introduction of film holes will lead to defects, stress concentration and other adverse effects, destroying the mechanical properties of the blades. The film cooling effect is affected by the geometric structure (hole type and layout) of the film holes. The different film hole geometric structures will also change the effect on mechanical properties. It is an urgent problem to reasonably design the geometric structure of film holes to improve the cooling effect while reducing the adverse effects on mechanical properties. This paper first explains the influence and mechanism of the existence of film holes on the creep and fatigue properties of turbine blades from a macroscopic and microscopic perspective, and then focuses on analyzing the specific changes in the creep life and fatigue life of the specimens with the change of the geometric structure of the film holes. The research progress on the influence of the layout and hole type of film holes on mechanical properties is summarized. Finally, the suggestions for the future research direction and engineering application of film holes are proposed.