TY - GEN
T1 - Direct numerical simulation of turbulent flow and aeroacoustic fields around an airfoil using lattice boltzmann method
AU - Kusano, Kazuya
AU - Yamada, Kazutoyo
AU - Furukawa, Masato
AU - Moon, Kil Ju
N1 - Funding Information:
The present research was partially supported by Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Young Scientists (B), KAKENHI 25820048, 2015.
Publisher Copyright:
© Copyright 2016 by ASME.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - The paper presents a result of the direct numerical simulation with the lattice Boltzmann method which was conducted for quantitative prediction of turbulent broadband noise. For better prediction of broadband noise with high frequency, which is generally generated in high Reynolds number flows, not only high grid resolution is required for a flow simulation to capture very small eddies of the sound source inside the turbulent boundary layer, but also the computation of acoustic field is often needed. In such case, the direct simulation of flow field and acoustic field is straightforward and effective. In this study, the direct simulation with the lattice Boltzmann method was conducted for a flow around the NACA0012 airfoil with the Reynolds number of two hundred thousand. In order to efficiently simulate this high Reynolds number flow with the LBM, the multi-scale approach was introduced in conjunction with the Building-cube method, while keeping the advantage of the LBM with the Cartesian mesh. At the condition with angle-of-attack of 9 degrees, a laminar separation bubble arises on the suction surface near the leading-edge and the suction boundary layer downstream of it is turbulent due to the separated-flow transition. As a result, turbulent broadband noise is generated from the boundary layer over the airfoil with the separated-flow transition. In the paper, as for prediction of such broadband noise, the computed frequency spectrum of far-field sound is validated to agree with the experimental result. In addition, through the detailed analyses of turbulent properties of the turbulent boundary layer on the suction surface, the validity of the present direct numerical simulation is demonstrated.
AB - The paper presents a result of the direct numerical simulation with the lattice Boltzmann method which was conducted for quantitative prediction of turbulent broadband noise. For better prediction of broadband noise with high frequency, which is generally generated in high Reynolds number flows, not only high grid resolution is required for a flow simulation to capture very small eddies of the sound source inside the turbulent boundary layer, but also the computation of acoustic field is often needed. In such case, the direct simulation of flow field and acoustic field is straightforward and effective. In this study, the direct simulation with the lattice Boltzmann method was conducted for a flow around the NACA0012 airfoil with the Reynolds number of two hundred thousand. In order to efficiently simulate this high Reynolds number flow with the LBM, the multi-scale approach was introduced in conjunction with the Building-cube method, while keeping the advantage of the LBM with the Cartesian mesh. At the condition with angle-of-attack of 9 degrees, a laminar separation bubble arises on the suction surface near the leading-edge and the suction boundary layer downstream of it is turbulent due to the separated-flow transition. As a result, turbulent broadband noise is generated from the boundary layer over the airfoil with the separated-flow transition. In the paper, as for prediction of such broadband noise, the computed frequency spectrum of far-field sound is validated to agree with the experimental result. In addition, through the detailed analyses of turbulent properties of the turbulent boundary layer on the suction surface, the validity of the present direct numerical simulation is demonstrated.
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U2 - 10.1115/FEDSM2016-7585
DO - 10.1115/FEDSM2016-7585
M3 - Conference contribution
AN - SCOPUS:85021939159
T3 - American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM
BT - Symposia
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 2016 Fluids Engineering Division Summer Meeting, FEDSM 2016, collocated with the ASME 2016 Heat Transfer Summer Conference and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels
Y2 - 10 July 2016 through 14 July 2016
ER -