Magnetic and Thermal Diffusion Effects on a Three-Dimensional Free Convective Flow Past a Uniformly Moving Porous Vertical Plate
The problem of a three dimensional free convection flow with mass transfer of an incompressible viscous electrically conducting fluid past a uniformly moving porous vertical plate with transverse sinusoidal suction velocity is considered. A magnetic field of uniform strength is assumed to be applied normal to the plate. The expressions for skin-friction at the plate in the direction of flow, rate of heat transfer in terms of Nusselt number, rate of mass transfer in terms of Sherwood number, velocity field, temperature field and species concentration field are obtained in non-dimensional forms. The effects of Hartmann number, Schmidt number, Soret number, Reynolds number on the skin friction, Nusselt number, Sherwood number, velocity field, temperature field and concentration field are discussed graphically and the results are physically interpreted.
SORET EFFECTS DUE TO NATURAL CONVECTION BETWEEN HEATED INCLINED PLATES WITH MAGNETIC FIELD
The effect of small uniform magnetic field on separation of a binary mixture for the case of a fully developed natural convection between two heated inclined plates has been investigated in this paper. Neglecting the induced electric field the equations governing the motion, temperature and concentration are solved by simple perturbation technique, in terms of dimensionless parameter measuring buoyancy force. The expressions for velocity, temperature and concentration are obtained. The effects of Hartmann number (M), thermal diffusion number (td), the buoyancy force parameter (N) and the inclination angle (ψ) of the plates with the horizontal are studied on the flow and heat transfer quantities.
Line Arrester Energy Discharge Duties
Surge arresters could practically eliminate lightning flashovers on distribution lines, if they are properly deployed in large enough numbers, and if they could survive the current and energy discharge duties imposed by high-magnitude lightning strokes. The discharge duty depends on complex interactions between the arrester locations, grounding, shielding from nearby objects, and the local lightning environment. But many factors of traditional concern with distribution arrester application, such as the lead length, surge front time, and protective margin, play little or no role in the discharge duty. Probabilistic methods determine the expected arrester failure rate. This should be much lower than the original flashover rate on the line insulation, otherwise the design is not acceptable. A transient program such as EMTP/ATP provides the best tool for calculating the discharge duty, but simplified methods are also available