Analysis of streamwise vortices in a supersonic turbine cascade

Author(s)

Lui, Hugo F. S. ; Wolf, William R. ; Ricciardi, Tulio R. ; Gaitonde, Datta, V

• Document type: Journal article
• Source: AIAA AVIATION FORUM AND ASCEND 2024; v. N/A, p. 10-pg., 2024-01-01.

Abstract

An investigation of streamwise vortices is performed in a supersonic turbine cascade by post-processing wall-resolved large eddy simulation data. For the present flow, the inlet Mach number is M-infinity = 2.0, and the Reynolds number is set as Re = 395, 000. Previous research highlighted the role of near-wall large-scale streaks in driving the separation bubble breathing motion for the current configuration. The present study aims to investigate how streamwise vortices affect the transport of near-wall streaks and, subsequently, the contraction of the separation bubble. For this purpose, Lagrangian coherent structures are extracted from the velocity fields at the leading and trailing edges of the bubble (prior and after the incident shock) by computing the finite-time Lyapunov exponent. As the bubble contracts, there is a noticeable increase in mixing, with the fluid being transported by the streamwise vortices from the high-speed region over the bubble, in the shear layer, towards the wall. This process occurs at specific spanwise locations, resulting in the bubble contraction or even local flow reattachment. (AU)

• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 21/06448-0 - High-fidelity numerical simulations applied in unsteady aerodynamics, turbulence and aeroacoustics
• Grantee: William Roberto Wolf
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 19/26196-5 - Large-eddy simulations of supersonic axial turbines
• Grantee: Hugo Felippe da Silva Lui
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 21/14199-0 - Investigation of shock-boundary layer interactions in supersonic axial turbines
• Grantee: Hugo Felippe da Silva Lui
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate