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.
Three-dimensional free convective MHD flow and heat transfer through a porous medium
The three-dimensional free convective flow of an incompressible viscous and electrical conducting fluid though a porous medium in the presence of a transverse magnetic field is discussed here. It is found that magnetic field and the permeability parameter have significant elfect on the flow and heat transfer.
Atmospheric drag effects on the KOMPSAT-1 satellite during geomagnetic superstorms
We examine the atmospheric drag on the low earth-orbiting satellite, KOMPSAT-1 in a sun-synchronous orbit at ~685-km altitude starting in 1999, during a 3-month (October-December) period in 2003. This 3-month interval includes the October 29-30 and November 20 magnetic superstorms and weak to moderate storms. We observed that the daily KOMPSAT-1 drag acceleration transiently responses to transient storm-time disturbances. That is, there is an one-to-one correspondence between the KOMPSAT-1 drag accelerations and the storm events. We find that the drag acceleration correlates strongly with the level of geomagnetic disturbance. This indicates that the trajectory of KOMPSAT-1 is significantly perturbed during extremely disturbed intervals because of atmospheric density increase. The main contributor to the density increase is Joule heating associated with the geomagnetic activity rather than the solar EUV radiation, as reported by previous studies. We suggest that understanding how the upper atmosphere responses to the geomagnetic-associated heating is important to predict space weather impacts on low earth-orbiting satellites.