Aims. Some basic structures in planetary nebulae are modeled as self-organized magnetohydrodynamic (MHD) plasma configurations with radial flow. Methods. These configurations are described by time self-similar dynamics, where space and time dependences of each physical variable are in separable form. Axisymmetric toroidal MHD plasma configuration is solved under the gravitational field of a cen...

Properties of a gas flow in the axisymmetric case with zero angular momentum in the supersonic region is explored for accretion onto a small compact object, in particular, onto Schwarzschild black hole when the velocity of the object is less than the sound velocity at infinity. First, it is shown that for ballistic flow, i.e. for zero pressure gradient, flow lines intersection occurs in the fro...

Radial electron heat transport in a low collisionality, current-carrying resistive plasma confined in an axisymmetric toroidal magnetic field is hypothesized to be caused by the paleoclassical collisional processes of parallel electron heat conduction and radial magnetic field diffusion. The electron distribution is Maxwellianized and the electron temperature equilibrated over a long length L (...

In this paper, we consider a vertically positioned cylindrical filtering element. Filtering occurs in the radial direction, therefore, direction of velocities liquid and suspended particles coincide with direction. The flow can be considered to one-dimensional radially axisymmetric. To describe such process, axisymmetric Stefan problem will formulated. mass balance formalism Darcy’s law are uti...

Radial electron heat transport in a low-collisionality, current-carrying resistive plasma confined in an axisymmetric toroidal magnetic field is hypothesized to be caused by the paleoclassical collisional processes of parallel electron heat conduction and radial magnetic-field diffusion. The electron distribution is Maxwellianized and the electron temperature equilibrated over a long length L t...

This paper presents numerical solutions and idealized analytical solutions of axisymmetric, f -plane models of the tropical cyclone boundary layer. In the numerical model, the boundary layer radial and tangential flow is forced by a specified pressure field, which can also be interpreted as a specified gradient balanced tangential wind field vgr(r) or vorticity field ζgr(r). When the specified ...

The hydrodynamical problem of flow in proximal renal tubule is investigated by considering axisymmetric flow of a viscous, incompressible fluid through a long narrow tube of varying cross-section with reabsorption at the wall. Two cases for reabsorption have been studied (i) when the bulk flow, Q, decays exponentially with the axial distance x, and (ii) when Q is an arbitrary function of x such...

We investigate stability of Toomre-Hayashi model for a self-gravitating, rotating gas disk. The rotation velocity, vφ, and sound speed, cs, are spatially constant in the model. We show that the model is unstable against an axisymmetric perturbation irrespectively of the values of vφ and cs. When the ratio, vφ/cs, is large, the model disk is geometrically thin and unstable against an axisymmetri...

Cool weakly ionized gaseous rotating disk form the basis for many models in astrophysics objects. Instabilities against perturbations in such disks play an important role in the theory of the formation of stars and planets. Traditionally, axisymmetric magnetohydrodynamic (MHD) and recently Hall-MHD instabilities have been thoroughly studied as providers of an efficient mechanism for radial tran...

Global stationary configurations of both aligned and logarithmic spiral magnetohydrodynamic (MHD) perturbations are constructed analytically within an axisymmetric background of razor-thin scale-free gas disc, which is embedded in an axisymmetric gravitational potential of a dark matter halo and involves an isopedic magnetic field almost vertically threaded through the disc plane. The scale-fre...