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The mean wall-normal velocity in turbulent boundary layer flows under pressure gradient

Published online by Cambridge University Press:  16 November 2023

Tie Wei*
Affiliation:
Department of Mechanical Engineering, New Mexico Tech, Socorro, NM 87801, USA
Zhaorui Li
Affiliation:
Department of Engineering, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412, USA
Tobias Knopp
Affiliation:
Institute of Aerodynamics and Flow Technology, DLR (German Aerospace Center), Bunsenstr. 10, 37073 Gottingen, Germany
Ricardo Vinuesa
Affiliation:
FLOW, Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden
*
Email address for correspondence: tie.wei@nmt.edu

Abstract

Using a combination of proper variable transformation and integral methods, we rigorously derive an analytical formulation for the mean wall-normal velocity in turbulent boundary layers (TBLs) subjected to arbitrary pressure gradients. The accuracy and robustness of this novel formulation are validated extensively through comparisons with two independent sets of numerical simulation data, demonstrating excellent agreement in both near-equilibrium and non-equilibrium TBLs. In addition, the robustness of the analytical formulations to various choices of boundary-layer edge definition is further confirmed in non-equilibrium TBLs. Our formulation includes a streamwise derivative term, which has minimal significance in near-equilibrium TBLs but plays a crucial role in determining the mean wall-normal velocity in non-equilibrium TBLs. Moreover, we investigate the physical significance of the pre-factors associated with the mean wall-normal velocity components, and unveil a close connection between a previously defined pressure gradient parameter and the ratio of these pre-factors in the analytical equation governing the mean wall-normal velocity. The insights gained from the examination of the pre-factors and their connection to the pressure gradient parameter offer valuable knowledge for interpreting and predicting the behaviour of turbulent boundary layers in various practical applications.

Type
JFM Papers
Copyright
© The Author(s), 2023. Published by Cambridge University Press

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References

Alfredsson, P.H., Segalini, A. & Örlü, R. 2011 A new scaling for the streamwise turbulence intensity in wall-bounded turbulent flows and what it tells us about the ‘outer’ peak. Phys. Fluids 23 (4), 041702.CrossRefGoogle Scholar
Bobke, A., Vinuesa, R., Örlü, R. & Schlatter, P. 2017 History effects and near equilibrium in adverse-pressure-gradient turbulent boundary layers. J. Fluid Mech. 820, 667692.CrossRefGoogle Scholar
Cantwell, B.J. 2021 Integral measures of the zero pressure gradient boundary layer over the Reynolds number range $0 \leq {Re}_\tau < \infty$. Phys. Fluids 33 (8), 085108.CrossRefGoogle Scholar
Castillo, L. & George, W.K. 2001 Similarity analysis for turbulent boundary layer with pressure gradient: outer flow. AIAA J. 39 (1), 4147.CrossRefGoogle Scholar
Clauser, F.H. 1954 Turbulent boundary layers in adverse pressure gradients. J. Aeronaut. Sci. 21, 91108.CrossRefGoogle Scholar
Coleman, G.N., Rumsey, C.L. & Spalart, P.R. 2018 Numerical study of turbulent separation bubbles with varying pressure gradient and Reynolds number. J. Fluid Mech. 847, 2870.CrossRefGoogle ScholarPubMed
Coles, D.E. & Hirst, E.A. 1969 Computation of Turbulent Boundary Layers – 1968 AFOSR-IFP-Stanford Conference. Thermosciences Division, Department of Mechanical Engineering, Stanford University.Google Scholar
Devenport, W.J. & Lowe, K.T. 2022 Equilibrium and non-equilibrium turbulent boundary layers. Prog. Aerosp. Sci. 131, 100807.CrossRefGoogle Scholar
Griffin, K.P., Fu, L. & Moin, P. 2021 General method for determining the boundary layer thickness in nonequilibrium flows. Phys. Rev. Fluids 6 (2), 024608.CrossRefGoogle Scholar
Knopp, T. 2022 An empirical wall law for the mean velocity in an adverse pressure gradient for RANS turbulence modelling. Flow Turbul. Combust. 109, 571601.CrossRefGoogle Scholar
Knopp, T., Reuther, N., Novara, M., Schanz, D., Schülein, E., Schröder, A. & Kähler, C.J. 2021 Experimental analysis of the log law at adverse pressure gradient. J. Fluid Mech. 918, A17–1A17–32.CrossRefGoogle Scholar
Maciel, Y., Rossignol, K.-S. & Lemay, J. 2006 A study of a turbulent boundary layer in stalled-airfoil-type flow conditions. Exp. Fluids 41 (4), 573590.CrossRefGoogle Scholar
Mellor, G.L. 1966 The effects of pressure gradients on turbulent flow near a smooth wall. J. Fluid Mech. 24 (2), 255274.CrossRefGoogle Scholar
Mellor, G.L. & Gibson, D.M. 1966 Equilibrium turbulent boundary layers. J. Fluid Mech. 24 (2), 225253.CrossRefGoogle Scholar
Monty, J.P., Harun, Z. & Marusic, I. 2011 A parametric study of adverse pressure gradient turbulent boundary layers. Intl J. Heat Fluid Flow 32 (3), 575585.CrossRefGoogle Scholar
Rotta, J. 1950 Über die Theorie turbulenter Grenzschichten. Tech. Rep. Mitteilungen aus dem Max-Planck-Institut für Strömungsforschung Nr. 1. (Translated as: On the theory of turbulent boundary layers. NACA Technical Memorandum no. 1344, 1953.).Google Scholar
Schlichting, H. 1979 Boundary-Layer Theory. McGraw-Hill.Google Scholar
Skåre, P.E. & Krogstad, P.A. 1994 A turbulent equilibrium boundary layer near separation. J. Fluid Mech. 272, 319348.CrossRefGoogle Scholar
Subrahmanyam, M.A., Cantwell, B.J. & Alonso, J.J. 2022 A universal velocity profile for turbulent wall flows including adverse pressure gradient boundary layers. J. Fluid Mech. 933, A16.CrossRefGoogle Scholar
Tennekes, H. & Lumley, J.L. 1972 A First Course in Turbulence. MIT Press.CrossRefGoogle Scholar
Townsend, A.A. 1956 The Structure of Turbulent Shear Flow. Cambridge University Press.Google Scholar
Vinuesa, R., Bobke, A., Örlü, R. & Schlatter, P. 2016 On determining characteristic length scales in pressure-gradient turbulent boundary layers. Phys. Fluids 28 (5), 055101.CrossRefGoogle Scholar
Vinuesa, R., Negi, P., Atzori, M., Hanifi, A., Henningson, D.S. & Schlatter, P. 2018 Turbulent boundary layers around wing sections up to $Re_c=1\,000\,000$. Intl J. Heat Fluid Flow 72, 8699.CrossRefGoogle Scholar
Wei, T. & Klewicki, J. 2016 Scaling properties of the mean wall-normal velocity in zero-pressure-gradient boundary layers. Phys. Rev. Fluids 1 (8), 082401.CrossRefGoogle Scholar
Wei, T. & Knopp, T. 2023 Outer scaling of the mean momentum equation for turbulent boundary layers under adverse pressure gradient. J. Fluid Mech. 958, A9.CrossRefGoogle Scholar
Wei, T., Li, Z. & Wang, Y. 2023 a New formulations for the mean wall-normal velocity and Reynolds shear stress in turbulent boundary layer under zero pressure gradient. J. Fluid Mech. 969, A3:1A3:15.CrossRefGoogle Scholar
Wei, T., Liu, X., Li, Z. & Livescu, D. 2023 b Planar turbulent wakes under pressure gradient: integral and self-similarity analyses. Phys. Fluids 35 (4), 045149.CrossRefGoogle Scholar
Young, D., Munson, B.R., Okishi, T.H. & Huebsch, W. 2007 A Brief Introduction to Fluid Mechanics, 4th edn. Wiley.Google Scholar