Year: 2020
Author: Yogesh G. Bhumkar, Bikash Mahato, Naveen Ganta, Yogesh G. Bhumkar
Numerical Mathematics: Theory, Methods and Applications, Vol. 13 (2020), Iss. 1 : pp. 27–62
Abstract
Numerical investigation of sound generation due to unsteady laminar flow past elliptic cylinders has been carried out using direct numerical simulation $(DNS)$ approach at a free-stream Mach number of $0.2$. Effects of aspect ratio $(0.6\le AR\le 1.0)$ and Reynolds number $(100\le Re \le 160)$ on the characteristics of radiated sound fields are analyzed. Two-dimensional compressible fluid flow equations are solved on a refined grid using high resolution dispersion relation preserving $(DRP)$ schemes. Using present $DNS$ data, equivalent noise sources as given by various acoustic analogies are evaluated. Amplitudes and frequencies associated with these noise sources are further related to characteristics of disturbance pressure fields. Disturbance pressure fields are intensified with increase in Reynolds number and aspect ratio. Thus, radiated sound power increases with increase in Reynolds number and aspect ratio. Among various cases studied here, minimum and maximum values of radiated sound power are found at $Re=120$ & $AR=0.6$ and $Re=160$ & $AR=1.0$, respectively. Directivity patterns show that the generated sound fields are dominated by the lift dipole for all cases. Next, proper orthogonal decomposition $(POD)$ technique has been implemented for decomposing disturbance pressure fields. The $POD$ modes associated with the lift and the drag dipoles have been identified. $POD$ analyses also clearly display that the radiated sound fields are dominated by the lift dipole only. Further, acoustic and hydrodynamic modes obtained using Doak's decomposition method have confirmed the patterns of radiated sound field intensities.
You do not have full access to this article.
Already a Subscriber? Sign in as an individual or via your institution
Journal Article Details
Publisher Name: Global Science Press
Language: English
DOI: https://doi.org/10.4208/nmtma.OA-2019-0042
Numerical Mathematics: Theory, Methods and Applications, Vol. 13 (2020), Iss. 1 : pp. 27–62
Published online: 2020-01
AMS Subject Headings:
Copyright: COPYRIGHT: © Global Science Press
Pages: 36
Keywords: Computational aeroacoustics acoustic analogies aeolian tones proper orthogonal decomposition Doak's decomposition.
Author Details
-
Effective control of aeolian tone using a pair of splitter plates
Mahato, Bikash | Ganta, Naveen | Bhumkar, Yogesh G.Journal of Sound and Vibration, Vol. 494 (2021), Iss. P.115906
https://doi.org/10.1016/j.jsv.2020.115906 [Citations: 5] -
Direct simulations of external flow and noise radiation using the generalized interpolation-supplemented cascaded lattice Boltzmann method
Song, Jian | Zhang, Fan | Zhao, Yuanpu | Ren, Feng | Hu, HaibaoComputers & Fluids, Vol. 280 (2024), Iss. P.106347
https://doi.org/10.1016/j.compfluid.2024.106347 [Citations: 0] -
A hydro-acoustic mode decomposition method for velocity and pressure field and application to a subsonic turbulent jet
Physics of Fluids, Vol. 35 (2023), Iss. 7
https://doi.org/10.1063/5.0157377 [Citations: 1] -
New time-marching methods for compressible Navier-Stokes equations with applications to aeroacoustics problems
Yadav, Vivek S. | Ganta, Naveen | Mahato, Bikash | Rajpoot, Manoj K. | Bhumkar, Yogesh G.Applied Mathematics and Computation, Vol. 419 (2022), Iss. P.126863
https://doi.org/10.1016/j.amc.2021.126863 [Citations: 8] -
Prediction of the aerodynamic sound generated due to flow over a cylinder performing combined steady rotation and rotary oscillations
Ganta, Naveen | Mahato, Bikash | Bhumkar, Yogesh G.The Journal of the Acoustical Society of America, Vol. 147 (2020), Iss. 1 P.325
https://doi.org/10.1121/10.0000585 [Citations: 8] -
Mitigation of aerodynamic sound for a laminar flow past a square cylinder using a pair of cowl plates
Mahato, Bikash | Ganta, Naveen | Bhumkar, Yogesh G.Physics of Fluids, Vol. 32 (2020), Iss. 7
https://doi.org/10.1063/5.0010932 [Citations: 10]