A one equation explicit algebraic subgrid-scale stress model

S. Hickel*, A. K. Gnanasundaram, T. Pestana

*Corresponding author for this work

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

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Abstract

Nonlinear Explicit Algebraic Subgrid-scale Stress Models (EASSMs) have shown high potential for Large Eddy Simulation (LES) of challenging turbulent flows on coarse meshes. A simplifying assumption made to enable the purely algebraic nature of the model is that the Subgrid-Scale (SGS) kinetic energy production and dissipation are in balance, i.e., P/ε = 1. In this work, we propose an improved EASSM design that does not involve this precalibration and retains the ratio P/ε as a space and time dependent variable. Our model is based on the partial differential evolution equation for the SGS kinetic energy ksgs and the assumption that the ratio P/ε evolves slower in time than ksgs. Computational results for simple cases of forced isotropic turbulence show that the new model is able to track the evolution of the SGS kinetic energy significantly better than the dynamic and non-dynamic EASSMs of Marstorp et al. (2009). Also the predicted kinetic energy spectra and resolved dissipation evolution are in excellent agreement with reference data from Direct Numerical Simulations (DNS).

Original languageEnglish
Title of host publicationProceedings of the11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019
Subtitle of host publication30/07/19 - 2/08/19 Southampton, United Kingdom
Number of pages6
Publication statusPublished - 2019
Event11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019 - Southampton, United Kingdom
Duration: 30 Jul 20192 Aug 2019

Conference

Conference11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019
Country/TerritoryUnited Kingdom
CitySouthampton
Period30/07/192/08/19

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