In this paper, we study the steady solutions of Euler-Poisson equations in bounded domains with prescribed angular velocity. This models a rotating Newtonian star consisting of a compressible perfect fluid with given equation of state P = eSργ . When the domain is a ball and the angular velocity is constant, we obtain both existence and non-existence theorems, depending on the adiabatic gas con...

A statistical mechanics canonical spherical energy-enstrophy theory of the super-rotation phenomenon in a quasi-2D barotropic fluid coupled by inviscid topographic torque to a rotating solid body, is solved in closed form in Fourier space, with inputs on the value of the energy to enstrophy quotient of the fluid, and two planetary parameters radius of the planet and its rate and axis of spin. T...

We study stationary axisymmetric configurations of a star model consisting of two barotropic fluids, which are uniformly rotating at two different rotation rates. Analytic approximate solutions in the limit of slow rotation are obtained with the classical method of Chandrasekhar, which consists of an expansion of the solution in terms of the rotation rate, and which is generalized to the case o...

We investigate the enhancement of both mixing and heat transfer in a two-rod mixer for highly-viscous non-Newtonian fluids. The mixer is composed of two vertical, circular rods in a cylindrical tank. Chaotic flows are obtained by imposing the temporal modulations of the rotational velocities of the walls. We study the effects of different stirring protocols, which lead to non-chaotic and chaoti...

following recent works of several authors like huilgol, bhattacharya etd. and javadpour et al., this paper is to contribute further to the literature of axial flow in a rotational coaxial rheometer. we consider axial flow of herschel bulkley mode1 between two concentric cylinders with the inner one rotating, while the outer cylinder is held stationary. an attempt has been made to direct the ana...

This paper deals with a mathematical modeling of flow stability Newtonian and non-Newtonian fluids in the gap between two concentric cylinders, one which rotates. A typical feature is formation vortex flow, so-called Taylor vortices. Vortex structures are affected by speed rotating cylinder physical properties fluids, i.e., viscosity density. Analogy terms assumed for magnetorheological fluids....

Steady, spherically symmetric, adiabatic accretion and wind flows around non-rotating black holes were studied for fully ionized, multi-component fluids, which are described by a relativistic equation of state (EoS). We showed that the polytropic index depends on the temperature as well as on the composition of fluids, so the composition is important to the solutions of the flows. We demonstrat...