The University of Southampton
University of Southampton Institutional Repository

Direct numerical simulation of a supersonic turbulent boundary layer subject to adverse pressure gradient induced by external successive compression waves

Direct numerical simulation of a supersonic turbulent boundary layer subject to adverse pressure gradient induced by external successive compression waves
Direct numerical simulation of a supersonic turbulent boundary layer subject to adverse pressure gradient induced by external successive compression waves

A freestream Mach 2.9 flat-plate supersonic turbulent boundary layer subject to a "pure" adverse pressure gradient (APG) without the impact of wall curvatures is studied by direct numerical simulation and compared with a benchmark flow with zero pressure gradient. Due to APG, the streamwise velocity shows an increase in the near-wall region and a reduction in the outer boundary layer. The principal strain rate shows a sandwich distribution along the wall-normal direction. The mismatch between the temperature and velocity fluctuations in both the inner and the outer layer is observed. Enhanced LSMs (large-scale motions) and large velocity patches are the typical flow structures in the outer and inner boundary layer subject to APG, respectively. From the analysis of quadrant decomposition, the sweep events dominate in the near-wall region while ejection events dominate the rest of the boundary layer. It is found that the baroclinicity plays a significant role in the formation of the enhanced LSMs in the outer boundary layer and the near-wall velocity patches. The resulting amplified vorticity further drives the interactive motions of the outer fluid and inner fluid. The turbulent kinetic energy and turbulent Mach number profiles are amplified by APG and a second peak is observed in both profiles. Turbulent energy budget analysis demonstrates that both the production and viscous effects are strengthened in the near-wall region while in the outer layer, the production is significantly amplified and balanced by the increased convection and turbulent transport.

2158-3226
Wang, Xu
aa5b0bc4-7c30-4020-808a-d91d17fb4bc8
Wang, Zhenguo
19cc9426-43ed-4cda-b150-dfc2e054049c
Sun, Mingbo
2df9eb75-e5d8-48cf-b8e1-00b0b77b3a90
Wang, Qiancheng
ed92bab4-2c5d-49a4-918d-c7fb48d90799
Hu, Zhiwei
dd985844-1e6b-44ba-9e1d-fa57c6c88d65
Wang, Xu
aa5b0bc4-7c30-4020-808a-d91d17fb4bc8
Wang, Zhenguo
19cc9426-43ed-4cda-b150-dfc2e054049c
Sun, Mingbo
2df9eb75-e5d8-48cf-b8e1-00b0b77b3a90
Wang, Qiancheng
ed92bab4-2c5d-49a4-918d-c7fb48d90799
Hu, Zhiwei
dd985844-1e6b-44ba-9e1d-fa57c6c88d65

Wang, Xu, Wang, Zhenguo, Sun, Mingbo, Wang, Qiancheng and Hu, Zhiwei (2019) Direct numerical simulation of a supersonic turbulent boundary layer subject to adverse pressure gradient induced by external successive compression waves. AIP Advances, 9 (8), [085215]. (doi:10.1063/1.5112040).

Record type: Article

Abstract

A freestream Mach 2.9 flat-plate supersonic turbulent boundary layer subject to a "pure" adverse pressure gradient (APG) without the impact of wall curvatures is studied by direct numerical simulation and compared with a benchmark flow with zero pressure gradient. Due to APG, the streamwise velocity shows an increase in the near-wall region and a reduction in the outer boundary layer. The principal strain rate shows a sandwich distribution along the wall-normal direction. The mismatch between the temperature and velocity fluctuations in both the inner and the outer layer is observed. Enhanced LSMs (large-scale motions) and large velocity patches are the typical flow structures in the outer and inner boundary layer subject to APG, respectively. From the analysis of quadrant decomposition, the sweep events dominate in the near-wall region while ejection events dominate the rest of the boundary layer. It is found that the baroclinicity plays a significant role in the formation of the enhanced LSMs in the outer boundary layer and the near-wall velocity patches. The resulting amplified vorticity further drives the interactive motions of the outer fluid and inner fluid. The turbulent kinetic energy and turbulent Mach number profiles are amplified by APG and a second peak is observed in both profiles. Turbulent energy budget analysis demonstrates that both the production and viscous effects are strengthened in the near-wall region while in the outer layer, the production is significantly amplified and balanced by the increased convection and turbulent transport.

Text
1.5112040 - Version of Record
Available under License Creative Commons Attribution.
Download (10MB)

More information

Accepted/In Press date: 8 August 2019
e-pub ahead of print date: 19 August 2019
Published date: August 2019

Identifiers

Local EPrints ID: 436349
URI: http://eprints.soton.ac.uk/id/eprint/436349
ISSN: 2158-3226
PURE UUID: 3c6119c3-55d4-44df-beb9-df90023ad976

Catalogue record

Date deposited: 06 Dec 2019 17:30
Last modified: 07 Oct 2020 00:53

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×