Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
The Backscatter on Large Eddy Solutions and on Solution obtained with Non-Linear Disturbance Equation
Submission Author:
Ricardo Galdino da SIlva , SP
Co-Authors:
Ricardo Galdino da SIlva, Marcos Pimenta
Presenter: Ricardo Galdino da SIlva
doi://10.26678/ABCM.COBEM2017.COB17-1602
Abstract
We apply a Large Eddy Simulation with subgrid stress computed by means of an additional transport equation for subgrid kinetic energy and an approach to solving turbulence flow based on Non-Linear Disturbance Equation to solve fully developed turbulent channel flow at Re τ = 395. The open source code, called OpenFOAM, is used in the present effort. From the numerical results, firstly, the backscatter, which is the energy transfer in inverse direction of a Richardson cascade of energy (the energy is transfer from big scale to the small scale), is quantified. Secondly, the mesh refinement effect on the backscatter and on the accuracy of the solution is analyzed for Large Eddy Simulation and Non-Linear Disturbance Equation. Finally, we correlate the solution accuracy with the lack or excess of backscatter and forward-scatter. The solutions obtained with the most refined mesh and Non-Linear Disturbance Equation show that the maximum effect of backscatter takes place in buffer-layer of channel boundary layer. In addition, the solutions computed with Non-Linear Disturbance Equation present more turbulent fluid dynamics, which can be measured by turbulent energy dissipation associated with backscatter and forward-scatter, than those obtained with Large Eddies Simulations.
Keywords
CFD, Turbulence Model, Backscatter, Large Eddy Simulation, turbulent channel flow
