scholarly journals The dissipation tensor in wall turbulence

2016 ◽  
Vol 807 ◽  
pp. 386-418 ◽  
Author(s):  
G. A. Gerolymos ◽  
I. Vallet
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
Plane Channel ◽  
Transport Equations ◽  
Wall Turbulence ◽  
Reynolds Stresses ◽  
Turbulent Plane ◽  
Plane Channel Flow ◽  
Derivatives Of

The paper investigates the dissipation tensor$\unicode[STIX]{x1D700}_{ij}$in wall turbulence. Available direct numerical simulation (DNS) data are examined to illustrate the differences in the anisotropy of the dissipation tensor$\unicode[STIX]{x1D700}_{ij}$with respect to the anisotropy of the Reynolds stresses$\unicode[STIX]{x1D633}_{ij}$. The budgets of the transport equations of the dissipation tensor$\unicode[STIX]{x1D700}_{ij}$are studied using novel DNS data of low Reynolds number turbulent plane channel flow with spatial resolution sufficiently fine to accurately determine the correlations of products of two-derivatives of fluctuating velocities$u_{i}^{\prime }$and pressure$p^{\prime }$which appear in various terms. Finally, the influence of the Reynolds number on the diagonal components of$\unicode[STIX]{x1D700}_{ij}$($\unicode[STIX]{x1D700}_{xx}$,$\unicode[STIX]{x1D700}_{yy}$,$\unicode[STIX]{x1D700}_{zz}$) and on the various terms in their transport equations is studied using available DNS data of Vreman and Kuerten (Phys. Fluids, vol. 26, 2014b, 085103).

The Destruction-of-Dissipation Tensor εεij in Wall Turbulence

2017 ◽  
Author(s):  
G. A. Gerolymos ◽  
I. Vallet
Keyword(s):  
Reynolds Number ◽  
Channel Flow ◽  
Plane Channel ◽  
Wall Turbulence ◽  
Scaling Relations ◽  
Pressure Term ◽  
Turbulent Plane ◽  
Plane Channel Flow ◽  
Production Mechanisms ◽  
Molecular Viscosity

The paper investigates the destruction-of-dissipation tensor εεij in low-Reynolds number turbulent plane channel flow. This tensor, which represents the destruction of the dissipation tensor εij (appearing in the budgets of the covariances of fluctuating velocities rij) by molecular viscosity, exhibits specific near-wall anisotropy and is not 2-C at the wall. The budgets of εεij (turbulent and viscous diffusion, pressure-term, various production mechanisms, and destruction by molecular viscosity εεεij) are studied and various scaling relations are examined.

scholarly journals Pressure, density, temperature and entropy fluctuations in compressible turbulent plane channel flow

2014 ◽  
Vol 757 ◽  
pp. 701-746 ◽  
Author(s):  
G. A. Gerolymos ◽  
I. Vallet
Keyword(s):  
Channel Flow ◽  
Plane Channel ◽  
Correlation Coefficients ◽  
Statistical Modelling ◽  
Transport Equations ◽  
Wall Turbulence ◽  
State Variables ◽  
Turbulent Plane ◽  
Thermodynamic Variables ◽  
Plane Channel Flow

AbstractWe investigate the fluctuations of thermodynamic state variables in compressible aerodynamic wall turbulence, using results of direct numerical simulation (DNS) of compressible turbulent plane channel flow. The basic transport equations governing the behaviour of thermodynamic variables (density, pressure, temperature and entropy) are reviewed and used to derive the exact transport equations for the variances and fluxes (transport by the fluctuating velocity field) of the thermodynamic fluctuations. The scaling with Reynolds and Mach number of compressible turbulent plane channel flow is discussed. Statistics and correlation coefficients of the thermodynamic fluctuations are examined. Finally, detailed budgets of the transport equations for the variances and fluxes of the thermodynamic variables are analysed. The implications of these results, leading both to the understanding of the thermodynamic interactions in compressible wall turbulence and to possible improvements in statistical modelling, are assessed. Finally, the required extension of existing DNS data to fully characterise this canonical flow is discussed.

0507 Peta-Scale Direct Numerical Simulation of Wall Turbulence at High Reynolds Number by K computer

2013 ◽  
Vol 2013 (0) ◽  
pp. _0507-01_-_0507-02_
Author(s):  
Naoya FUKUSHIMA ◽  
Kazuaki TOKUMARU ◽  
Hiroya MAMORI ◽  
Kaoru IWAMOTO ◽  
Koji FUKAGATA ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
High Reynolds Number ◽  
Wall Turbulence ◽  
High Reynolds

Direct Numerical Simulation of a Fully Developed Turbulent Channel Flow With Respect to the Reynolds Number Dependence

2001 ◽  
Vol 123 (2) ◽  
pp. 382-393 ◽  
Author(s):  
Hiroyuki Abe ◽  
Hiroshi Kawamura ◽  
Yuichi Matsuo
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
Channel Flow ◽  
Correlation Coefficients ◽  
Turbulent Channel Flow ◽  
Reynolds Numbers ◽  
Reynolds Stresses ◽  
Point Correlation ◽  
Reynolds Number Dependence

Direct numerical simulation (DNS) of a fully developed turbulent channel flow for various Reynolds numbers has been carried out to investigate the Reynolds number dependence. The Reynolds number is set to be Reτ=180, 395, and 640, where Reτ is the Reynolds number based on the friction velocity and the channel half width. The computation has been executed with the use of the finite difference method. Various turbulence statistics such as turbulence intensities, vorticity fluctuations, Reynolds stresses, their budget terms, two-point correlation coefficients, and energy spectra are obtained and discussed. The present results are compared with the ones of the DNSs for the turbulent boundary layer and the plane turbulent Poiseuille flow and the experiments for the channel flow. The closure models are also tested using the present results for the dissipation rate of the Reynolds normal stresses. In addition, the instantaneous flow field is visualized in order to examine the Reynolds number dependence for the quasi-coherent structures such as the vortices and streaks.

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