We examine the angular momentum transport properties of disks composed of macroscopic particles whose velocity dispersions are externally enhanced (“stirred”). Our simple Boltzmann equation model serves as an analogy for unmagnetized fluid disks in which turbulence may be driven by thermal convection. We show that interparticle collisions in particle disks play the same role as fluctuating pres...

We examine the angular momentum transport properties of disks composed of macroscopic particles whose velocity dispersions are externally enhanced (“stirred”). Our simple Boltzmann equation model serves as an analogy for unmagnetized fluid disks in which turbulence may be driven by thermal convection. We show that interparticle collisions in particle disks play the same role as fluctuating pres...

Numerical studies were conducted using Lattice Boltzmann Method (LBM) to study the natural convection in a square cavity in the presence of roughness. An algorithm based on a single relaxation time Bhatnagar-Gross-Krook (BGK) model of Lattice Boltzmann Method (LBM) was developed. Roughness was introduced on both the hot and cold walls in the form of sinusoidal roughness elements. The study was ...

We consider a model for phase separation in binary viscous liquids that allows for material transport due to cross-diffusion of unlike particles and convection by the hydrodynamic bulk flow. Typically, during the evolution, the average size of domains of the pure phases increases with time — a phenomenon called coarsening. Siggia [24] predicts that at an initial stage, coarsening proceeds mainl...

We investigate the origin of deterministic chaos in the Belousov–Zhabotinsky (BZ) reaction carried out in closed and unstirred reactors (CURs). In detail, we develop a model on the idea that hydrodynamic instabilities play a driving role in the transition to chaotic dynamics. A set of partial differential equations were derived by coupling the two variable Oregonator–diffusion system to the Nav...

In the present paper an analysis of mixed convection of an unsteady magneto hydrodynamic (MHD) flow of an incompressible viscous fluid through porous media due to a vertical porous stretching sheet in the presence of viscous dissipation, thermal radiation and heat source /sink has been carried out. The fluid considered is viscous and incompressible. The governing partial differential equations ...

The hydrodynamic effects on the late stage kinetics of phase separation in liquid mixtures is studied using the model H. Mass and momentum transport are coupled via a nonequilibrium body force, which is proportional to the Peclet number alpha, i.e., the ratio between convective and diffusive molar fluxes. Numerical simulations based on this theoretical model show that phase separation in low vi...

Many kinetic models of the Boltzmann equation have a diiusive scaling that leads to the Navier-Stokes type parabolic equations, such as the heat equation, the porous media equations, the advection-diiusion equation and the viscous Burgers equation. In such problems the diiusive relaxation parameter may diier in several orders of magnitude from the rareeed regimes to the hydrodynamic (diiusive) ...

Close insight into mathematical and conceptual structure of classical field theories shows serious inconsistencies in their common basis. In other words, we claim in this work to have come across two severe mathematical blunders in the very foundations of theoretical hydrodynamics. One of the defects concerns the traditional treatment of time derivatives in Eulerian hydrodynamic description. Th...