Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study
The Atwood number plays a critical role in describing the physics of fluids behind the hydrodynamic instabilities in gas dynamics. In order to investigate the impacts of the Atwood number (At), the evolution of a shock-accelerated square bubble containing either SF6, Kr, Ar, Ne, or He and surrounded...
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sg-ntu-dr.10356-1468252023-02-28T20:04:46Z Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study Singh, Satyvir School of Physical and Mathematical Sciences Engineering::Mechanical engineering::Fluid mechanics Fluid Instabilities Fluid Mechanics The Atwood number plays a critical role in describing the physics of fluids behind the hydrodynamic instabilities in gas dynamics. In order to investigate the impacts of the Atwood number (At), the evolution of a shock-accelerated square bubble containing either SF6, Kr, Ar, Ne, or He and surrounded by N2 is investigated numerically. For this purpose, the unsteady compressible Navier-Stokes-Fourier equations are solved using an explicit modal discontinuous Galerkin method. For validation, the numerical results are compared with available experimental results and are found to be in good agreement. The results demonstrate that the Atwood number has a significant influence on flow morphology with wave patterns, vortex creation, vorticity generation, and bubble deformation. For At > 0, the speed of the shock wave traveling along with the bubble inner surface is often less than that of the incident shock wave and greater than that of the transmitted shock wave. Moreover, vortex pairs from the upstream and downstream corners are generated, and the former vortex pair ultimately dominates the flow morphology. For At ≈ 0, the incident and transmitted shock waves move at the same speeds, whereas for At < 0, the transmitted shock wave travels faster than the incident shock wave. Moreover, only one vortex pair at the upstream corners is generated, which dominates the flow morphology. Furthermore, a detailed study of Atwood number impacts is investigated through the vorticity generation at interfaces. A quantitative analysis based on the shock trajectories, the interface features, and the integral diagnostics is also studied in detail to investigate the impacts of the Atwood number on the flow structure. Finally, a comparative study of the flow physics between the shock-accelerated square and cylindrical bubbles is conducted to examine their natural differences. Nanyang Technological University Published version The author acknowledges the financial support provided by the Nanyang Technological University, Singapore, through the NAP-SUG grant. 2021-03-12T08:08:57Z 2021-03-12T08:08:57Z 2020 Journal Article Singh, S. (2020). Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study. Physics of Fluids, 32(12), 126112-. https://dx.doi.org/10.1063/5.0031698 1070-6631 0000-0001-6669-5296 https://hdl.handle.net/10356/146825 10.1063/5.0031698 2-s2.0-85099229774 12 32 126112 en NAP, M408074 Physics of Fluids © 2020 The Author(s). All rights reserved. This paper was published by AIP Publishing in Physics of Fluids and is made available with permission of The Author(s). application/pdf |
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Engineering::Mechanical engineering::Fluid mechanics Fluid Instabilities Fluid Mechanics Singh, Satyvir Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
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The Atwood number plays a critical role in describing the physics of fluids behind the hydrodynamic instabilities in gas dynamics. In order to investigate the impacts of the Atwood number (At), the evolution of a shock-accelerated square bubble containing either SF6, Kr, Ar, Ne, or He and surrounded by N2 is investigated numerically. For this purpose, the unsteady compressible Navier-Stokes-Fourier equations are solved using an explicit modal discontinuous Galerkin method. For validation, the numerical results are compared with available experimental results and are found to be in good agreement. The results demonstrate that the Atwood number has a significant influence on flow morphology with wave patterns, vortex creation, vorticity generation, and bubble deformation. For At > 0, the speed of the shock wave traveling along with the bubble inner surface is often less than that of the incident shock wave and greater than that of the transmitted shock wave. Moreover, vortex pairs from the upstream and downstream corners are generated, and the former vortex pair ultimately dominates the flow morphology. For At ≈ 0, the incident and transmitted shock waves move at the same speeds, whereas for At < 0, the transmitted shock wave travels faster than the incident shock wave. Moreover, only one vortex pair at the upstream corners is generated, which dominates the flow morphology. Furthermore, a detailed study of Atwood number impacts is investigated through the vorticity generation at interfaces. A quantitative analysis based on the shock trajectories, the interface features, and the integral diagnostics is also studied in detail to investigate the impacts of the Atwood number on the flow structure. Finally, a comparative study of the flow physics between the shock-accelerated square and cylindrical bubbles is conducted to examine their natural differences. |
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School of Physical and Mathematical Sciences |
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School of Physical and Mathematical Sciences Singh, Satyvir |
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Singh, Satyvir |
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Singh, Satyvir |
title |
Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
title_short |
Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
title_full |
Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
title_fullStr |
Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
title_full_unstemmed |
Role of Atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
title_sort |
role of atwood number on flow morphology of a planar shock-accelerated square bubble : a numerical study |
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2021 |
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https://hdl.handle.net/10356/146825 |
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1759854920906833920 |