Dynamics of the large-scale structures and associated noise emission in airfoil slats

Autor(es)

Souza, Daniel S. ^{[1, 2, 3]} ; Rodriguez, Daniel ^{[1, 4, 5, 6]} ; Himeno, Fernando H. T. ^[1] ; Medeiros, Marcello A. F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Aeronaut Engn, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Joao del Rei, Dept Thermal & Fluid Sci, Praca Frei Orlando, Praca Frei Orlando 170, Sao Joao Del Rei - Brazil

^[3] UNESP Sao Paulo State Univ, Campus Sao Joao Boa Vista, BR-13876750 Sao Joao Da Boa Vista, SP - Brazil

^[4] UPM, Sch Aeronaut, ETSIAE, Plaza Cardenal Cisneros 3, E-28040 Madrid - Spain

^[5] Univ Fed Fluminense, Mech Engn Dept, BR-24210240 Niteroi, RJ - Brazil

^[6] UPM, ETSIAE, Madrid - Spain

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF FLUID MECHANICS; v. 875, p. 1004-1034, SEP 25 2019.
• Citações Web of Science: 0

Resumo

We investigate the slat narrowband peak noise generating mechanism. Unsteady flow data were generated by a lattice-Boltzmann-based commercial code for four configurations, accounting for variations of the airfoil angle of attack and slat overlap. Comparison with experimental results indicates that the aspects of the flow field relevant for the generation of the narrowband peaks were accurately captured. Frequency-domain proper orthogonal decomposition (POD) is applied to identify dominant large-scale structures in the frequency range dominated by the peaks. The combined use of the two POD metrics, namely, the turbulent kinetic energy in the turbulent flow region and the acoustic pressure in the far field, demonstrated that the structures most correlated with the noise resemble spanwise coherent Kelvin-Helmholtz vortices which dominate the slat cove only at the frequency of the narrowband peaks. Time evolution of the structures educed using the acoustic pressure correlation provides detailed evidence of the hydrodynamic and acoustic steps of a Rossiter-like feedback mechanism between the slat cusp and trailing edge. The combined analysis of results for the different slat configurations provides an explanation for the effect of the slat configuration on the amplitude of the narrowband peaks observed in previous studies, particularly the influence of the main-element suction peak. (AU)

• Processo FAPESP: 16/02970-5 - Estudo computacional do efeito aeroacústico de um selo localizado na cova do eslate e análise através de técnica POD
• Beneficiário: Fernando Henrique Tadashi Himeno
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 18/02542-9 - Estudo numérico de pacotes de onda sobre placa plana com rugosidade
• Beneficiário: Fernando Henrique Tadashi Himeno
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 06/52568-7 - Aeronave silenciosa: uma investigação em aeronáutica
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Parceria para Inovação Tecnológica - PITE