The purpose of this study is to determine more accurately the marginal stability condition for axisymmetric waves since it is believed that an unstable axisymmetric wave could affect the amplification of spiral waves. An axisymmetric wave with a gradient term of velocity dispersion ( surface density ) is derived. Analysis of this axisymmetric wave with a gradient term for our own galaxy shows t...

— In the weak field and slow motion approximation of general relativity a new approach in deriving the secular Lense-Thirring effect on the orbital elements of a test body in the external field of different central rotating sources exhibiting axial symmetry is presented. The approach adopted in the present work, in the case of a perfectly spherical source, leads to the well known Lense-Thirring...

Flow visualization by the schlieren technique in the neighbourhood of a fully developed cavity on two axisymmetric headforms has shown the existence of laminar boundary-layer separation upstream of cavitation separation, and the distance between the two separations to be strongly dependent on Reynolds number. Based on present results, a semi-empirical method is developed to predict the position...

This investigation presents a mathematical model describing the momentum, heat and mass transfer characteristics of magnetohydrodynamic MHD flow and heat generating/absorbing fluid near a stagnation point of an isothermal two-dimensional body of an axisymmetric body. The fluid is electrically conducting in the presence of a uniform magnetic field. The series solution is obtained for the resulti...

We investigate how the choice of either no-slip or stress-free boundary conditions affects numerical models of rapidly rotating flow in Earth's core by computing solutions of the weakly-viscous magnetostrophic equations within a spherical shell, driven by a prescribed body force. For non-axisymmetric solutions, we show that models with either choice of boundary condition have thin boundary laye...

The forcing term in the lattice Boltzmann equation (LBE) is usually used to mimic Navier-Stokes equations with a body force. To derive axisymmetric model, forcing terms are incorporated into the two-dimensional (2D) LBE to mimic the additional axisymmetric contributions in 2D Navier-Stokes equations in cylindrical coordinates. Many axisymmetric lattice Boltzmann D2Q9 models were obtained throug...

Growth of Rayleigh-Taylor (R-T) instabilities under the axisymmetric explosion are investigated by two-dimensional hydrodynamical calculations. The degree of the axisymmetric explosion and amplitude of the initial perturbation are varied parametrically to find the most favorable parameter for reproducing the observed line profile of heavy elements. It is found that spherical explosion can not p...

The theory of diffusion is one of the prevailing theories on the explanation of the quality of dissemination of innovations, expansion of ideas and thoughts in the area of culture.The present research is an attempt to respond to this question: Is it possible to disseminate the Islamic Revolution values and ideals through the window of Abrahamic Hajj into the world of Islam? And if the res...

We develop tracking control laws for a rigid spacecraft using both thrusters and momentum wheels. The model studied comprises a rigid body with external thrusters and with N rigid axisymmetric wheels controlled by axial torques. The thruster torques and the axial motor torques are the controls used to track given attitude motions. Specifically, the thruster torques are used to implement the coa...