Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow
Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow
Direct numerical simulations were conducted to uncover physical aspects of a transverse sonic jet injected into a supersonic cross-flow at a Mach number of 2.7. Simulations were carried out for two different jet-to-cross-flow momentum flux ratios of 2.3 and 5.5. It is identified that collision shock waves behind the jet induce a herringbone separation bubble in the near-wall jet wake and a reattachment valley is formed and embayed by the herringbone recirculation zone. The recirculating flow in the jet leeward separation bubble forms a primary trailing counter-rotating vortex pair (TCVP) close to the wall surface. Analysis on streamlines passing the separation region shows that the wing of the herringbone separation bubble serves as a micro-ramp vortex generator and streamlines acquire angular momentum downstream to form a secondary surface TCVP in the reattachment valley. Herringbone separation wings disappear in the far field due to the cross-interaction of lateral supersonic flow and the expansion flow in the reattachment valley, which also leads to the vanishing of the secondary TCVP. A three-dimensional schematic of surface trailing wakes is presented and explains the formation mechanisms of the surface TCVPs.
supersonic flow, jet in crossflow, counter-rotating vortex pair
551-583
Sun, Mingbo
2df9eb75-e5d8-48cf-b8e1-00b0b77b3a90
Hu, Zhiwei
dd985844-1e6b-44ba-9e1d-fa57c6c88d65
10 September 2018
Sun, Mingbo
2df9eb75-e5d8-48cf-b8e1-00b0b77b3a90
Hu, Zhiwei
dd985844-1e6b-44ba-9e1d-fa57c6c88d65
Sun, Mingbo and Hu, Zhiwei
(2018)
Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow.
Journal of Fluid Mechanics, 850, .
(doi:10.1017/jfm.2018.455).
Abstract
Direct numerical simulations were conducted to uncover physical aspects of a transverse sonic jet injected into a supersonic cross-flow at a Mach number of 2.7. Simulations were carried out for two different jet-to-cross-flow momentum flux ratios of 2.3 and 5.5. It is identified that collision shock waves behind the jet induce a herringbone separation bubble in the near-wall jet wake and a reattachment valley is formed and embayed by the herringbone recirculation zone. The recirculating flow in the jet leeward separation bubble forms a primary trailing counter-rotating vortex pair (TCVP) close to the wall surface. Analysis on streamlines passing the separation region shows that the wing of the herringbone separation bubble serves as a micro-ramp vortex generator and streamlines acquire angular momentum downstream to form a secondary surface TCVP in the reattachment valley. Herringbone separation wings disappear in the far field due to the cross-interaction of lateral supersonic flow and the expansion flow in the reattachment valley, which also leads to the vanishing of the secondary TCVP. A three-dimensional schematic of surface trailing wakes is presented and explains the formation mechanisms of the surface TCVPs.
Text
jfm2018-final submission
- Accepted Manuscript
More information
Accepted/In Press date: 21 May 2018
e-pub ahead of print date: 6 July 2018
Published date: 10 September 2018
Keywords:
supersonic flow, jet in crossflow, counter-rotating vortex pair
Identifiers
Local EPrints ID: 421182
URI: http://eprints.soton.ac.uk/id/eprint/421182
ISSN: 0022-1120
PURE UUID: 63138b2b-69bc-4f47-b6a0-f264b71886d4
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Date deposited: 24 May 2018 16:30
Last modified: 16 Mar 2024 06:40
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Author:
Mingbo Sun
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