Abstract
In this paper, we perform direct numerical simulation (DNS) of turbulent boundary layers at Mach 5 with the ratio of wall-to-edge temperature T w/T ℘ from 1.0 to 5.4 (Cases M5T1 to M5T5). The influence of wall cooling on Morkovin's scaling, Walz's equation, the standard and modified strong Reynolds analogies, turbulent kinetic energy budgets, compressibility effects and near-wall coherent structures is assessed. We find that many of the scaling relations used to express adiabatic compressible boundary-layer statistics in terms of incompressible boundary layers also hold for non-adiabatic cases. Compressibility effects are enhanced by wall cooling but remain insignificant, and the turbulence dissipation remains primarily solenoidal. Moreover, the variation of near-wall streaks, iso-surface of the swirl strength and hairpin packets with wall temperature demonstrates that cooling the wall increases the coherency of turbulent structures. We present the mechanism by which wall cooling enhances the coherence of turbulence structures, and we provide an explanation of why this mechanism does not represent an exception to the weakly compressible hypothesis. © 2010 Cambridge University Press.
Recommended Citation
L. Duan et al., "Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 2. Effect Of Wall Temperature," Journal of Fluid Mechanics, vol. 655, pp. 419 - 445, Cambridge University Press, Jan 2010.
The definitive version is available at https://doi.org/10.1017/S0022112010000959
Department(s)
Mechanical and Aerospace Engineering
Publication Status
Open Access
International Standard Serial Number (ISSN)
1469-7645; 0022-1120
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 Cambridge University Press, All rights reserved.
Publication Date
01 Jan 2010
Comments
National Aeronautics and Space Administration, Grant NNX08ADO4A