[en] An analysis of the mass transfer in an unsteady two-dimensional flow past an accelerated infinite vertical plate has been carried out under the following conditions: (1) The heat-transfer is varied at the plate (2) the non-dimensional time t is small and (3) Prandtl and Schmidt number is equal to one. Approximate solutions for the coupled non-linear equations are obtained for the velocity and temperature. The numerical values of the skin friction and the rate of heat transfer are tabulated. (Auth.)

[en] In this paper Lagrangian Densities are considered containing fluxes as well as potentials and their derivatives. By means of a Hamilton Principle the field equations and the equations of motion are derived independently of each other. (Auth.)

[en] The paper studies the combined free and forced convection in a rotating, viscous, incompressible fluid confined between two parallel porous plates. Assuming that the temperature varies linearly along the plates and the pressure gradient maintained uniform over the planes parallel to the plates, the velocity, temperature and the stresses are calculated analytically. Their behaviours for different values of the parameters viz., the Hartmann number, the Grashoff number and the suction parameter etc., are discussed graphically giving out the interplay between the various forces. (Auth.)

[en] It is proved that the only circulation preserving hydromagnetic motion whose vorticity is steady, lamellar and bears a constant magnitude on a vortex-line are (1) a plane motion of constant vorticity (on which certain unsteady potential motions may be superposed), and (2) a particular circular helical motion. (Auth.)

[en] The effect of the vertical magnetic field of uniform strength on the stability of natural convection in a thin horizontal fluid layer subject to horizontal as well as vertical temperature gradient has been studied on the basis of linear theory. The boundaries are taken to be rigid, perfectly thermally and electrically conducting having prescribed temperatures and the horizontal temperature gradient is assumed to be small. The analysis is restricted to the case when Prandtl number is greater than magnetic Prandtl number which is met by a large margin under most terrestrial conditions. It has been found that the preferred mode of disturbance is stationary and will be a transverse roll or a longitudinal roll depending on three parameters namely Prandtl number, Chandrasekhar number and the ratio of Prandtl number to magnetic Prandtl number. The critical Rayleigh numbers for various values of the above three parameters have been reported. (Auth.)

[en] Analytical solutions of the non-linear problem of violent explosions in a plasma of varying density under power law have been obtained. A critical law for a medium of decreasing density from the source of explosion is determined for which the problem admits a very simple solution but beyond this critical line analytical solutions admit another discontinuity automatically occuring inside a blast wave region. It is assumed that a disturbance caused by violent explosion due to sudden release of immense amount of energy is expanding very rapidly and is headed by a strong MHD shock wave. It is found that the discontinuity appearing inside a blast wave region causes a violation of continuum theory in the physical plane and consequently a cavity is formed. Analytical solutions predict that just before a discontinuity appears, the gas pressure falls to zero and the solution breaks down and can not be extended further. (Auth.)

[en] The authors have studied the viscous incompressible and slightly conducting fluid flow between two concentric rotating cylinders with non-erodable and non-conducting porous lining on the inner wall of the outer cylinder under the influence of a uniform radial magnetic field of the form Bsub(r) = A/r. They have solved the equations and have evaluated the velocity and temperature distributions, shearing stress and the rates of heat transfer coefficients. They have investigated the effects of the magnetic parameter, the non-dimensional measure of the thickness of the porous lining, the ratio of the velocities of the cylinders, the slip parameter, the porosity parameter, the Biot number and the product Psub(r)E on the physical quantities evaluated. (Auth.)

[en] The Falkner-Skan transformation has been generalized to study the boundary layer flow of a viscous incompressible conducting fluid past a flat plate in the presence of a uniform transverse magnetic field fixed to the plate. Keeping the convergence aspect in view series solution, different from the conventional, for the velocity boundary layer has been developed. It is found that only few terms in the series expansion are enough to give the skin-friction coefficient to a good degree of accuracy. (Auth.)

[en] Steady flow of an incompressible electrically conducting fluid between two coaxial cylinders composed of non-conducting materials, is considered in the presence of a uniform radial magnetic field. The flow is due to the relative motions of the cylinders parallel to their common axis. The cylinders are maintained at constant temperatures. Heat transfer rates from the cylinders are plotted graphically against the Hartmann number. (Auth.)

[en] The boundary layer growth with tensor electrical conductivity and the transpiration number has been examined using local nonsimilarity solutions method. It is found that suction will cause the increase in wall shearing stress and decrease in thicknesses of the boundary layer. (Auth.)