Assessment of Transitional Airfoil Flows through the Lattice-Boltzmann Method Part II: Finite Wing Effects

Author(s)

Ribeiro, Bernardo Luiz R. ; Dantas, Cayan A. ; Wolf, William R.

• Document type: Journal article
• Source: AIAA AVIATION FORUM AND ASCEND 2024; v. N/A, p. 11-pg., 2024-01-01.

Abstract

This study is the second in a two-part series, evaluating the ability of a lattice-Boltzmann high-fidelity simulation tool to resolve transitional flows with intermittent events. Here, the lattice-Boltzmann method (LBM) is employed to investigate the flow over a NACA0012 airfoil at an angle of attack of alpha = 3 degrees, freestream Mach number M-infinity = 0.3, and Reynolds number Re = 5 x 10(4). This flow configuration is typically found in the development of quiet air vehicles, making the study of noise generation mechanisms particularly relevant. For this case, a laminar separation bubble forms on the airfoil's suction side, leading to complex dynamics that include the shedding of coherent structures and the generation of trailing-edge tonal noise. For this second part, finite wing effects on the coherent structures are investigated and compared to the flow fields of a wing with periodic boundary conditions, as presented in the first part. The results indicate that the laminar separation bubble (LSB) on the suction side is significantly influenced by wing tip effects, forming much closer to the trailing edge than in the infinite wing. Additionally, an analysis of the vortex dynamics reveals distinct patterns of vortex shedding from the LSB, differing markedly from those observed in the spanwise homogeneous case. Overall, the finite wing impacts the pressure gradient along the wing, delaying the bubble formation and its subsequent vortex shedding and, hence, changing the acoustic noise generation. (AU)

• 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: 23/08768-7 - High-fidelity simulations of rotor configurations: Analysis of unsteady aerodynamics and aeroacoustics
• Grantee: Bernardo Luiz Rocha Ribeiro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral