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EPTT 2024
14th Spring School on Transition and Turbulence
Investigation of Finite Wing Effects in Transitional Airfoil Flows Using the Lattice-Boltzmann Method
Submission Author:
Bernardo Luiz Rocha Ribeiro , SP , Brazil
Co-Authors:
Bernardo Luiz Rocha Ribeiro, Cayan Antunes Dantas, William Wolf
Presenter: Bernardo Luiz Rocha Ribeiro
doi://10.26678/ABCM.EPTT2024.EPT24-0021
Abstract
This study evaluates 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 α = 3 deg., freestream Mach number M = 0.3, and Reynolds number Re = 50,000. 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. Finite wing effects on the coherent structures are investigated and compared to the flow fields of a wing with periodic boundary conditions. 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 periodic 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.
Keywords
Lattice Boltzmann, Transitional flow, Laminar separation bubble
