Laminar-turbulent transition and intermittency effects on secondary tones from a NACA0012 airfoil

Autor(es)

Ricciardi, Tulio R. ; Wolf, William R. ; Taira, Kunihiko

• Tipo de documento: Artigo Científico
• Fonte: AIAA AVIATION 2021 FORUM; v. N/A, p. 10-pg., 2021-01-01.

Resumo

A wall-resolved large eddy simulation (LES) is performed to study secondary tones generated in a transitional flow over a NACA0012 airfoil. The airfoil angle of attack is set as alpha = 3 degrees and the freestream Mach and Reynolds numbers are M-infinity = 0.3 and R-e = 5 x 10(4), respectively. A laminar separation bubble appears over the airfoil suction side, playing an important role in the flow dynamics. Inspection of flow structures and spectral analysis are employed to investigate vortex shedding aft of the suction side separation bubble. Detailed flow visualization shows that vortex interaction results in intermittent flow patterns with either vortex merging or bursting. As a consequence, coherent structures or turbulent packets advect towards the trailing edge with different levels of noise emission. The coherent structures are identified by high values of two-point pressure correlations along the spanwise direction. Despite the intermittent occurrence of laminar-turbulent transition, the noise spectrum depicts a main tone with multiple equidistant secondary tones. (AU)

• Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 19/20437-0 - Estratégias de Controle de Escoamento via Análise Resolvente com Aplicações em Ruído de Airframe
• Beneficiário: Tulio Rodarte Ricciardi
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 18/11835-0 - Investigação numérica do ruído gerado por trens de pouso
• Beneficiário: Tulio Rodarte Ricciardi
• Modalidade de apoio: Bolsas no Brasil - Doutorado