Investigation of the factors contributing to skin friction coefficient in a self-similar adverse pressure gradient (APG) turbulent boundary layer (TBL) flow using direct numerical simulation (DNS)

ORAL

Abstract

DNS is performed to solve the incompressible Navier-Stokes equation for pressure and velocity in a self-similar APG-TBL.2 We study the contributions to the skin friction coefficient (Cf) from turbulent fluctuations, viscous effects and pressure gradient. Cf is calculated based on the formulation given by Renard and Deck for boundary layer (BL) flows.3 The non-dimensional pressure gradient (β) is defined as β = δ1 Pe,x / τw where δ1 is the displacement thickness, Pe,x is the far-field pressure gradient and τw is the mean wall shear stress. The Cf decomposition is studied for three different BL flows with β = 0, 1 and 39. With increasing β, Cf approaches zero and the flow becomes more like a free shear layer. It is found that the contribution from viscous effects reduces as β changes from 0 to 39. The Reynolds stress remains the dominant contributor for all β and its contribution to Cf has a peak at y = δ1 for β = 39 where y is the wall normal direction.

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Presenters

  • Shevarjun Senthil

    Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne 3800, Australia

Authors

  • Shevarjun Senthil

    Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne 3800, Australia

  • Callum Atkinson

    Monash University, Laboratory for Turbulence Research in Aerospace and Combustion, Monash University, Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne 3800, Australia

  • Vassili Kitsios

    CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia, CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia, Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechani

  • Atsushi Sekimoto

    Department of Materials Engineering Science, Osaka University, Osaka 560-8531, Japan, Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical

  • Julio Soria

    Department of Mechanical & Aerospace Engineering, Monash University, Clayton,VIC,3800, Australia, Monash Univ, King Abdulaziz University, Monash University, Laboratory for Turbulence Research in Aerospace and Combustion, Monash University, Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne 3800, Australia