Vorticity moments in four numerical simulations of the 3D Navier-Stokes equations

Donzis, Diego A and Gibbon, John D and Gupta, Anupam and Kerr, Robert M and Pandit, Rahul and Vincenzi, Dario (2013) Vorticity moments in four numerical simulations of the 3D Navier-Stokes equations. In: JOURNAL OF FLUID MECHANICS, 732 . pp. 316-331.

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Abstract

The issue of intermittency in numerical solutions of the 3D Navier-Stokes equations on a periodic box 0, L](3) is addressed through four sets of numerical simulations that calculate a new set of variables defined by D-m(t) = (pi(-1)(0) Omega(m))(alpha m) for 1 <= m <= infinity where alpha(m) = 2m/(4m - 3) and Omega(m)(t)](2m) = L-3 integral(v) vertical bar omega vertical bar(2m) dV with pi(0) = vL(-2). All four simulations unexpectedly show that the D-m are ordered for m = 1,..., 9 such that Dm+1 < D-m. Moreover, the D-m squeeze together such that Dm+1/D-m NE arrow 1 as m increases. The values of D-1 lie far above the values of the rest of the D-m, giving rise to a suggestion that a depletion of nonlinearity is occurring which could be the cause of Navier-Stokes regularity. The first simulation is of very anisotropic decaying turbulence; the second and third are of decaying isotropic turbulence from random initial conditions and forced isotropic turbulence at fixed Grashof number respectively; the fourth is of very-high-Reynolds-number forced, stationary, isotropic turbulence at up to resolutions of 4096(3).

Item Type:	Journal Article
Publication:	JOURNAL OF FLUID MECHANICS
Publisher:	CAMBRIDGE UNIV PRESS
Additional Information:	Copyright for this article belongs to CAMBRIDGE UNIVERSITY PRESS
Keywords:	intermittency; isotropic turbulence; turbulence simulation
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	30 Oct 2013 06:28
Last Modified:	30 Oct 2013 06:28
URI:	http://eprints.iisc.ac.in/id/eprint/47614

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