Quadrant Analysis of Zero and Adverse Pressure Gradient Turbulent Boundary Layers using High Spatial Resolution 2C-2D PIV Measurements

POSTER

Abstract

High spatial resolution particle image velocimetry (PIV) has been used in an experiment in a $2m$ wide, $1m$ high and $20m$ long LML boundary layer wind tunnel to measure the instantaneous velocity fields of ZPG-TBL at $Re_{\delta_2} = 7,750$ and APG-TBL at $Re_{\delta_2} = 9,840$ ($\beta = 2.01$) and $Re_{\delta_2} = 16,240$ ($\beta = 2.27$). High spatial resolution enables the capture of TBL from the viscous sublayer to the end of the log layer. We study the effect of mild APG on the individual contribution of the four quadrants of fluctuations in the streamwise and the wall-normal velocities towards Reynolds shear stress. It is found that near the wall ($y^+ < 30$), contributions of the first and third quadrants relative to the second quadrant are higher than relative to the fourth quadrant but in opposite direction in all three cases of TBL. Above $y^+ = 30$, these relative contributions are nearly 45\% in ZPG-TBL and 50\% in APG-TBL. Below $y^+ = 10$, all four quadrants contribute more towards the total Reynolds shear stress with increasing APG.

*Australian Research Council Discovery Grant

Authors

  • Muhammad Shehzad

    • Lab. for Turbulence Research in Aerospace & Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia

  • Jean-Marc Foucaut

    • Université Lille Nord de France, LML-Laboratoire de Mécanique de Lille, Lille, France

  • Christophe Cuvier

    • Université Lille Nord de France, LML-Laboratoire de Mécanique de Lille, Lille, France

  • Christian Willert

    • German Aerospace Center (DLR), Institute of Propulsion Technology, Köln, Germany

  • Callum Atkinson

    • LTRAC, DMAE, Monash University
    • Monash University
    • Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University
    • Lab. for Turbulence Research in Aerospace & Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia

  • Julio Soria

    • Department of Mechanical and Aerospace Engineering, Monash University (Clayton Campus), VIC 3800, Australia
    • LTRAC, Department of Mechanical and Aerospace Engineering, Monash University, Clayton 3800, Australia.
    • Monash University
    • Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University
    • LTRAC, Department of Mechanical and Aerospace Engineering , Monash University, Clayton Campus, Melbourne, VIC3800, Australia
    • Lab. for Turbulence Research in Aerospace & Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia
    • LTRAC, DMAE, Monash University