Robert Rubinstein

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The lattice Boltzmann equation replaces continuous particle velocity space by a finite set; the velocity distribution function then varies over a finite-dimensional vector space instead of over an infinite-dimensional function space. The number of linearly independent moments of the distribution function in a lattice Boltzmann model cannot exceed the number(More)
Modeled dissipation rate transport equations are often derived by i n v oking various hypotheses to close correlations in the corresponding exact equations. D. C. Leslie suggested that these models might be derived instead from Kraichnan's wavenumber space integrals for inertial range transport power. This suggestion is applied to the destruction terms in(More)
A modified shell model for rotating turbulence is proposed. The effect of rotation is introduced by a randomized linear term. Randomization is shown to be important in correctly modeling the rotation effect. Numerical simulation shows that the exponent of the energy spectrum in the inertial range changes from -5/3 to -2 as rotation rate increases. The(More)
The sound radiated by isotropic turbulence is computed using inertial range scaling expressions for the relevant t w o time and two point correlations. The result depends on whether the decay of Eulerian time correlations is dominated by large scale sweeping or by local straining: the straining hypothesis leads to an expression for total acoustic power(More)
L'vov and Falkovich (Physica D 57) h a v e shown that the dimensionally possible inertial range scaling laws for Boussinesq turbulence, Kolmogorov and Bolgiano scaling, describe steady states with, respectively, constant ux of kinetic energy and of entropy. F ollowing Woodru (Phys. Fluids 6), these scaling laws are treated as similarity solutions of the(More)
Taylor series expansions of turbulent time correlation functions are applied to show that helicity influences Eulerian time correlations more strongly than Lagrangian time correlations: to second order in time, the hclicity effect on Lagrangian time correlations vanishes, but the helicity cffect on Eulerian time correlations is nonzero. Fourier analysis(More)