Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Investigation of shock-boundary layer interactions in a supersonic turbine cascade under different inlet Mach numbers
Submission Author:
Hugo Felippe da Silva Lui , SP
Co-Authors:
Hugo Felippe da Silva Lui, William Wolf, Tulio Rodarte Ricciardi
Presenter: Hugo Felippe da Silva Lui
doi://10.26678/ABCM.COBEM2023.COB2023-0223
Abstract
The effects of inlet Mach number on shock-boundary layer interactions (SBLIs) in a supersonic turbine cascade at Reynolds number 395,000, based on the axial chord, are studied using large eddy simulations and post-processing techniques. Three values of Mach number are considered 1.85, 2.00 and 2.15. Particular emphasis is placed on understanding the effects of inlet Mach number on the unsteadiness of the bubble/shock system. The present configuration depicts some differences on the shock structure when compared to canonical cases (impinging oblique shock on a flat plate and compression ramp) due to the curved walls of the turbine. On the suction side, an oblique shock interacts with the boundary layer, while a Mach reflection is formed on the pressure side. Flow visualizations and an analysis of the mean flow show that a higher inlet Mach number leads to a stronger leading edge bow shock that in turn generates a more inclined oblique shock, resulting in a downstream displacement of the SBLI region on both sides of the airfoil. A side consequence of the topological changes is an increase of the suction side separation bubble length as the inlet Mach number is increased. This effect is less pronounced on the pressure side, where the recirculation regions have similar lengths. Finally, the separation bubble dynamics is investigated using spectral analysis for all cases. The results indicate that, as the inlet Mach number increases, the regions with high-spectral energy at low-frequencies move downstream in the axial direction, and the SBLI systems excite even lower frequencies.
Keywords
Shock-Wave Boundary Layer Interactions, Supersonic Flow, Turbine, Large Eddy Simulation
