Agradecimentos: The authors acknowledge the financial support received from Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP, under Grants No. 2013/03413-4 and No. 2013/07375-0, and the financial support received from Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq,...

Agradecimentos: The authors acknowledge the financial support received from Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP, under Grants No. 2013/03413-4 and No. 2013/07375-0, and the financial support received from Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq, under Grants No. 470695/2013-7 and No. 309985/2013-7. The authors also acknowledge the FAEPEX M.Sc., fellowship provided to Bruno Backes by Pró-Reitoria de Pesquisa of Univerisity of Campinas, PRP-UNICAMP. The computational resources provided by CENAPAD-SP under Project No. 551 are also acknowledged

Aeroacoustic predictions of a model airframe noise problem are conducted to assess the effects of wake interaction on flow and acoustic fields. Simulations of unsteady low Reynolds number flows, including both noise generation and its subsequent propagation to the far field, are performed for a...

Aeroacoustic predictions of a model airframe noise problem are conducted to assess the effects of wake interaction on flow and acoustic fields. Simulations of unsteady low Reynolds number flows, including both noise generation and its subsequent propagation to the far field, are performed for a configuration composed of a cylinder placed above a NACA 0012 airfoil. An assessment of cylinder position and freestream Mach number effects on sound radiation is presented. It is observed that intense interference among cylinder and airfoil dipoles occurs for all configurations analyzed. In this case, each body scatters the sound emitted by the other. For moderate Mach number flows with wake interaction, quadrupole sources become important to the total acoustic prediction, specially for the downward noise radiation. In order to investigate how wake interaction affects noise radiation, a comparison between the current model problem with a single cylinder case is presented. Results show that wake interaction becomes a major feature of the airfoil-cylinder flow, causing a faster downstream decay of convecting disturbances when compared to the isolated cylinder case. This issue is further studied using a linear stability calculation for the wake interaction problem, which shows that for higher Mach numbers, compressibility effects lead to the formation of a wave-packet structure in the wake with higher maximum amplitude, higher convection Mach number and a sudden spatial decay. Therefore, wake interaction and compressibility effects play a key role in the present model problem and are proposed as responsible for the increase of quadrupole noise radiation

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

470695/2013-7; 309985/2013-7

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2013/03413-4; 2013/07375-0

Aberto