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...

District heating can provide cost-effective and low-carbon energy to local populations, such as space heating in winter and year-round hot/cold water; this is also associated with electricity generation in combined-heat-and-power systems. Although this is currently rare in the UK, many legislative policies, including the Renewable Heat Incentive, aim to increase the amount of energy from such s...

The effect of an axial electric field on the capillary instability of a cylindrical interface in the presence of heat and mass transfer has been investigated using viscous potential flow theory. In viscous potential flow, the viscous term in Navier-Stokes equation vanishes as vorticity is zero but viscosity is not zero. Viscosity enters through normal stress balance in the viscous potential flo...

This chapter summarizes the current knowledge on the numerical prediction of turbulent impinging jet flows. The predictive capabilities of numerical models are evaluated by careful comparison with experimental fluid flow and heat transfer data. Turbulent fluctuations in the velocity field are mathematically modelled using the Reynolds Averaged Navier–Stokes (RANS) methodology. Turbulence is ass...