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 this paper, a comprehensive study of hydromagnetic (MHD) axisymmetric stagnation point flow and heat transfer characteristics of an electrically conducting viscous incompressible micropolar fluid towards a shrinking sheet with radiation effects is investigated under the action of a transverse magnetic field. The governing partial differential equations (PDEs) are reduced to non linear ordina...

In this paper, heat transfer during simultaneously developing singlephase laminar flow inside a pipe has been investigated numerically. A two dimensional axisymmetric model of a circular mini-channel is used, with a constant wall temperature boundary condition. In the present simulations, flow Reynolds number (Re) and amplitude ratio (A) are kept constant to 200 and 0.2, respectively. The varia...

Context. The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. Aims. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this paper, we concentrate mainly on the behavior of non-axisymmetric perturbations in axisymmetric magnetic configurations. Methods. The stability is ...

A micromechanics based thermal model was developed to predict the temperature and degree of cure (DOC) distribution inside a unidirectional fiber reinforced composite during the curing process. Using the concentric cylinder assemblage (CCA) model as a representation of the composite microstructure, the effective thermodynamic properties of the composite were computed based on the fiber and matr...

The present work reports on a two-dimensional axisymmetric Ž nite element analysis of heat  ow during laser spot welding, taking into account the temperature dependence of the physical properties and latent heat of transformations. An analysis based on conduction heat transfer alone, but using the ‘double ellipsoidal’ representation of the laser beam, seems to be sufŽ cient to estimate the tra...