Effects of Various Injection Holes with/without Opening Angles of Film Cooling on Blades of Gas Turbine: A CFD Approach

Abstract

The combustor exit temperature is steadily rising to improve the overall efficiency of the gas turbine. As a result, film cooling, the most important and necessary cooling technology, must be developed further to satisfy this demanding requirement. The film cooling performance on the NACA 0012 gas turbine blade is numerically evaluated in this research using 6 different injection holes with and without opening angles. The Computational Fluid Dynamics (CFD) software Ansys Fluent v16 is used to conduct 2-dimensional Reynolds-Averaged Navier-Stokes (RANS) flow and heat transfer analyses. The flow is assumed to be steady, turbulent, and incompressible. To obtain solutions, the incompressible RANS equations are solved using the finite-volume technique. The simulation results indicate that the SST k-ω turbulence model is appropriate for simulating flow characteristics and evaluating film cooling efficiency over the blade. Furthermore, the opening angle has a beneficial impact on the upper blade surface's cooling performance. The injection hole with an opening angle of 15º and a height of D (injection hole diameter) achieves the maximum value of cooling efficiency. The coolant injected from the hole provides greater cooling coverage for the entire blade in this configuration, increasing cooling effectiveness.
 HIGHLIGHTS
 
 The influence of various geometries of injection holes on the effectiveness of film cooling was investigated
 The low opening angle has a greater impact on film cooling than the other opening angles
 The injection hole with an opening angle eliminates the recirculation region after the coolant exits
 
 GRAPHICAL ABSTRACT