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arXiv · 1903.12339

On the long time behavior of time relaxation model of fluids

Ali Pakzad
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Abstract

The time relaxation model, which is family of high accuracy turbulence models, has proven to be effective in regularization of Navier Stokes Equations. The model belongs to the class of Large Eddy Simulation models, and is derived by adding a linear time regularization term $\chi u^{\star}$ to the Navier Stokes Equations. The time relaxation operator truncates small solution scales by injecting an extra dissipation to a simulation, without altering appreciably the solution's large scales. Herein to evaluate the effect of the time regularization term on a simulation, the rate of energy dissipation of the model in body force driven turbulence is studied. Our result, which agrees with Kolmogorov's conventional turbulence theory, is also consistent with the rate proven for the NSE. Moreover, employing the model requires a choice of the coefficient $\chi$. It is known that the model's simulation is sensitive to the parameter. The analysis motivates a range of possible values for the coefficient $\chi$ in $3d$ turbulent flows away from walls.

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Ali Pakzad. 2019-03-29. On the long time behavior of time relaxation model of fluids. https://doi.org/10.1016/j.physd.2020.132509

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