Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers

Adrian Sescu, Mohammed Afsar, Yuji Hattori

Research output: Contribution to conferenceAbstract

Abstract

High-speed boundary layer transition has recently seen a resurgence of interest and reinvigoration, motivated by the need to improve the design and optimization of future hypersonic transport aircraft or reentry vehicles, increase the efficiency of high-speed engines, improve the flow in natural gas pipelines, or to quieten high-speed wind tunnels. In the pre-transitional stage, streamwise vortices and the associated streaks experience transient growth in boundary layer flows over flat or concave surfaces as a result of various disturbances initiated in the upstream region or from the wall. Here, we study the nonlinear progression of streaky structures in supersonic and hypersonic boundary layers via the full nonlinear compressible boundary region equations, which is the high Reynolds number asymptotic extension of the Navier-Stokes equations under the assumption that the streamwise wavenumber of the disturbances is much smaller than both wall-normal and spanwise wavenumbers. The base flow is excited either by freestream disturbances imposed at the upstream boundary or by disturbances from the wall in the form of wall transpiration. An extensive parametric study is performed in different flow conditions to assess the development of these streaky structures.
Original languageEnglish
Number of pages1
Publication statusPublished - 25 Nov 2019
Event72nd Annual Meeting of the APS Division of Fluid Dynamics : Division of Fluid Dynamics - Washington State Convention Center, Seattle, United States
Duration: 23 Nov 201926 Nov 2019
https://www.apsdfd2019.org/

Conference

Conference72nd Annual Meeting of the APS Division of Fluid Dynamics
Abbreviated titleAPS-DFD
CountryUnited States
CitySeattle
Period23/11/1926/11/19
Internet address

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Boundary layers
Vortex flow
Hypersonic boundary layers
Hypersonic vehicles
Transpiration
Transport aircraft
Natural gas pipelines
Boundary layer flow
Reentry
Navier Stokes equations
Wind tunnels
Reynolds number
Engines

Keywords

  • boundary layers
  • asymptotic analysis

Cite this

Sescu, A., Afsar, M., & Hattori, Y. (2019). Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers. Abstract from 72nd Annual Meeting of the APS Division of Fluid Dynamics , Seattle, United States.
Sescu, Adrian ; Afsar, Mohammed ; Hattori, Yuji. / Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers. Abstract from 72nd Annual Meeting of the APS Division of Fluid Dynamics , Seattle, United States.1 p.
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Sescu, A, Afsar, M & Hattori, Y 2019, 'Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers' 72nd Annual Meeting of the APS Division of Fluid Dynamics , Seattle, United States, 23/11/19 - 26/11/19, .

Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers. / Sescu, Adrian; Afsar, Mohammed; Hattori, Yuji.

2019. Abstract from 72nd Annual Meeting of the APS Division of Fluid Dynamics , Seattle, United States.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers

AU - Sescu, Adrian

AU - Afsar, Mohammed

AU - Hattori, Yuji

PY - 2019/11/25

Y1 - 2019/11/25

N2 - High-speed boundary layer transition has recently seen a resurgence of interest and reinvigoration, motivated by the need to improve the design and optimization of future hypersonic transport aircraft or reentry vehicles, increase the efficiency of high-speed engines, improve the flow in natural gas pipelines, or to quieten high-speed wind tunnels. In the pre-transitional stage, streamwise vortices and the associated streaks experience transient growth in boundary layer flows over flat or concave surfaces as a result of various disturbances initiated in the upstream region or from the wall. Here, we study the nonlinear progression of streaky structures in supersonic and hypersonic boundary layers via the full nonlinear compressible boundary region equations, which is the high Reynolds number asymptotic extension of the Navier-Stokes equations under the assumption that the streamwise wavenumber of the disturbances is much smaller than both wall-normal and spanwise wavenumbers. The base flow is excited either by freestream disturbances imposed at the upstream boundary or by disturbances from the wall in the form of wall transpiration. An extensive parametric study is performed in different flow conditions to assess the development of these streaky structures.

AB - High-speed boundary layer transition has recently seen a resurgence of interest and reinvigoration, motivated by the need to improve the design and optimization of future hypersonic transport aircraft or reentry vehicles, increase the efficiency of high-speed engines, improve the flow in natural gas pipelines, or to quieten high-speed wind tunnels. In the pre-transitional stage, streamwise vortices and the associated streaks experience transient growth in boundary layer flows over flat or concave surfaces as a result of various disturbances initiated in the upstream region or from the wall. Here, we study the nonlinear progression of streaky structures in supersonic and hypersonic boundary layers via the full nonlinear compressible boundary region equations, which is the high Reynolds number asymptotic extension of the Navier-Stokes equations under the assumption that the streamwise wavenumber of the disturbances is much smaller than both wall-normal and spanwise wavenumbers. The base flow is excited either by freestream disturbances imposed at the upstream boundary or by disturbances from the wall in the form of wall transpiration. An extensive parametric study is performed in different flow conditions to assess the development of these streaky structures.

KW - boundary layers

KW - asymptotic analysis

UR - http://meetings.aps.org/Meeting/DFD19/Session/P33.4

UR - https://www.apsdfd2019.org/

M3 - Abstract

ER -

Sescu A, Afsar M, Hattori Y. Growth of nonlinear streaky structures and the associated streamwise vortices in high-speed boundary layers. 2019. Abstract from 72nd Annual Meeting of the APS Division of Fluid Dynamics , Seattle, United States.