Print Email Facebook Twitter Turbulence modulation by variable density and viscosity Title Turbulence modulation by variable density and viscosity Author Patel, A. (TU Delft Energy Technology) Pecnik, Rene (TU Delft Energy Technology) Peeters, J.W.R. (TU Delft Energy Technology) Boersma, B.J. (TU Delft Process and Energy; TU Delft Energy Technology) Hickel, S. (TU Delft Aerodynamics) Moghadam, M.E. (Stanford University) Department Process and Energy Date 2017 Abstract We investigate the effectiveness of the semi-local Reynolds number Re τ to parametrize wall-bounded flows with strong density, ρ, and viscosity, µ, gradients. Several cases are considered, namely, volumetrically heated low-Mach-number turbulent channel flows, a simultaneously heated and cooled flow with CO2 at supercritical pressure, and heated and cooled supersonic boundary layer flows. The mean density and viscosity in some of these cases vary up to a factor of nine and six, respectively. We show that, even for such high gradients in mean properties, the velocity transformation based on the semi-local Reynolds number is able to collapse the mean streamwise velocity profiles. We further-more provide evidence that the turbulent kinetic energy and streamwise vorticity budget equations are also governed by the semi-local Reynolds number. For cases with strong property variations, additional mechanisms appear that are caused by individual density (e.g., baroclinicity) or viscosity gradients. However, in the cases investigated herein, these additional mechanisms are small. The insights gained are used to improve a wall model, which is then tested in a wall-modeled large-eddy simulation (LES) of a compressible channel flow with isothermal walls. To reference this document use: http://resolver.tudelft.nl/uuid:dd6b8281-0240-4609-9dec-98c69180a464 Publisher Center for Turbulence Research, Stanford University, USA Source Proceedings of the 2016 Summer Program: Studying Turbulence Using Numerical Simulation Databases - XVI Event Studying Turbulence Using Numerical Simulation Databases - XVI, 2016-06-26 → 2016-07-22, Stanford, United States Part of collection Institutional Repository Document type book chapter Rights © 2017 A. Patel, Rene Pecnik, J.W.R. Peeters, B.J. Boersma, S. Hickel, M.E. Moghadam Files PDF 66_Pecnik.pdf 906.05 KB Close viewer /islandora/object/uuid:dd6b8281-0240-4609-9dec-98c69180a464/datastream/OBJ/view