HALL CURRENT EFFECT ON THERMOSOLUTAL INSTABILITY IN A VISCOELASTIC FLUID FLOWING IN A POROUS MEDIUM

摘要

The thermosolutal instability in a layer of an electrically conducting Oldroydian viscoelastic fluid in a porous medium is studied to include the effect of Hall current. For the case of stationary convection, the Oldroydian fluid behaves like an ordinary Newtonian fluid. The magnetic field and the stable solute gradient are found to have stabilizing effects whereas Hall currents and medium permeability are found to have destabilizing effects on the system. Graphs are plotted by giving numerical values to the parameters to depict the stability characteristics. The sufficient conditions for the non-existence of overstability are also obtained.