Effects of mean flow convection, quadrupole sources and vortex shedding on airfoil overall sound pressure level

Autor(es)

Wolf, William R. ^{[1, 2, 3]} ; Azevedo, Joao L. F. ^[1] ; Lele, Sanjiva K. ^[3]

Afiliação do(s) autor(es)

^[1] Inst Aeronaut & Espaco, BR-12228903 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Estadual Campinas, BR-13083860 Campinas, SP - Brazil

^[3] Stanford Univ, Stanford, CA 94305 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Sound and Vibration; v. 332, n. 26, p. 6905-6912, DEC 23 2013.
• Citações Web of Science: 7

Resumo

This paper presents a further analysis of results of airfoil self-noise prediction obtained in the previous work using large eddy simulation and acoustic analogy. The physical mechanisms responsible for airfoil noise generation in the aerodynamic flows analyzed are a combination of turbulent and laminar boundary layers, as well as vortex shedding (VS) originated due to trailing edge bluntness. The primary interest here consists of evaluating the effects of mean flow convection, quadrupole sources and vortex shedding tonal noise on the overall sound pressure level (OASPL) of a NACA0012 airfoil at low and moderate freestream Mach numbers. The overall sound pressure level is the measured quantity which eventually would be the main concern in terms of noise generation for aircraft and wind energy companies, and regulating agencies. The Reynolds number based on the airfoil chord is fixed at Re-c = 408,000 for all flow configurations studied. The results demonstrate that, for moderate Mach numbers, mean flow effects and quadrupole sources considerably increase OASPL and, therefore, should be taken into account in the acoustic prediction. For a low Mach number flow with vortex shedding, it is observed that OASPL is higher when laminar boundary layer separation is the VS driving mechanism compared to trailing edge bluntness. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 13/07375-0 - CeMEAI - Centro de Ciências Matemáticas Aplicadas à Indústria
• Beneficiário: Francisco Louzada Neto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 11/12493-6 - Investigação de Geração e Propagação de Ruído Próprio de Aerofólios Usando Simulação de Grandes Escalas, Modelos Analíticos e Analogia Acústica
• Beneficiário: William Roberto Wolf
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado