Algorithms and Models for Turbulence Not at Statistical Equilibrium
Standard eddy viscosity models, while robust, cannot represent backscatter and have severe difficulties with complex turbulence not at statistical equilibrium. This report gives a new derivation of eddy viscosity models from an equation for the evolution of variance in a turbulent flow. The new derivation also shows how to correct eddy viscosity models. The report proves the corrected models preserve important features of the true Reynolds stresses. It gives algorithms for their discretization including a minimally invasive modular step to adapt an eddy viscosity code to the extended models. A numerical test is given with standard and over diffusive eddy viscosity models. The correction (scaled by 10-8) does exhibit intermittent backscatter.
N. Jiang and W. Layton, "Algorithms and Models for Turbulence Not at Statistical Equilibrium," Computers and Mathematics with Applications, vol. 71, no. 11, pp. 2352 - 2372, Elsevier, Jun 2016.
The definitive version is available at https://doi.org/10.1016/j.camwa.2015.10.004
Advances in Scientific Computing and Applied Mathematics, ASCAM-2015 (2015: Oct. 9–12, Las Vegas, NV)
Mathematics and Statistics
Keywords and Phrases
Algorithms; Backscattering; Reynolds number; Turbulence; Discretizations; Eddy viscosity; Eddy viscosity model; Important features; Minimally invasive; Numerical tests; Reynolds stress; Statistical equilibrium; Viscosity; Backscatter; Complex turbulence
International Standard Serial Number (ISSN)
Article - Conference proceedings
© 2016 Elsevier, All rights reserved.
01 Jun 2016