Design Space Exploration Studies on the 777-Shaped Film Cooling Hole With Lattice Boltzmann Method

Abstract Shaped film cooling holes play an important role in cooling of turbine blades. There have been very limited studies on design exploration of film cooling holes with high-fidelity numerical approaches. In this study, Lattice Boltzmann Method (LBM)-based numerical approach is used to perform a design of experiments study on the publicly available 777-shaped film cooling hole model. The geometric design parameters varied for this study were the forward expansion angle, the lateral expansion angle, and the slot injection angle. To establish a baseline reference solution, validation studies were first performed on the baseline design, and the results indicated excellent agreement with experimental test data. For the design studies, simulations were done on a coarser grid to achieve faster turnaround time. Design studies revealed that the best performing hole designs were with larger forward and lateral expansion angles while higher slot injection angles decreased the film cooling hole performance. It was also observed that for lower blowing ratios, the selected design parameters had minimal impact on the film cooling hole performance. Simulations were also performed at a higher mainstream Mach number and it was observed that design trends at lower mainstream Mach number studies also held true at higher Mach number. The cost of executing the DOE on relatively coarser grid sizes but with a high-fidelity approach like LBM appears to be feasible by industry standards.