Studies on Hydromagnetic Stability of Newtonian and Non-Newtonian Fluid

Abstract

In this thesis hydromagnetic stabilities with respect to both axisymmetric and non­axisymmetric perturbations of an incompressible perfectly conducting viscous fluid in presence of a magnetic field has been investigated. In chapter two, we have discussed the hydromagnetic stability with respect to axisymmetric disturbance of an in-compressible viscous fluid rotating between two perfectly conducting infinite co-axial cylinders in presence of a magnetic field by inner product method. The complex characteristic equation for the growth rate has been simplified and deduce propagation conditions for unstable, oscillatory and stable modes. In chapter three, hydromagnetic stability of helical flows in viscous fluid has been discussed. In chapter four, we have studied the flow of a highly conducting viscous incompressible fluid which is flowing between two paralled non-conducting planes in a uniform transverse magnetic field perpendicular to the plane. The results obtained have been discussed with the help of tables and graphs. In chapter five, we have investigated the unsteady Ml ID now of a visco-elastic Rivlin Ericksen fluid with transient pressure gradient through a uniform circular cylinder in a uniform transverse magnetic field. Here, the velocity profile of a fluid clement has been calculated theoretically and graphically. In chapter six, an attempt has been made to investigate the unsteady flow of an incompressible visco-elastic Rivlin-Ericksen fluid between two concentric cylinders with transient pressure gradient in a uniform transverse magnetic field. Here we have calculated the velocity profile of a fluid clement theoretically and graphically. In chapter seven, we have investigated the unsteady unidirectional now of an in­compressible visco-elastic oldroyd type fluid between two concentric cylinders under the action of a magnetic field with time varying body forces. Here we have calculated velocity profile of a fluid element theoretically and graphically, we also have discussed the stability of the velocity profile. ln chapter eight, Hyromagnetic Stability of visco­elastic oldroyd fluid with the time varying body force through a rectangular channel has been discussed……………………………