GRAVITOHYDROMAGNETIC STABILITY OF FLUID CYLINDER WITH SURFACE TENSION

Abstract

This thesis is mainly concemed with some stability problems of full fluid cylinder acted upon by self - gTavitating , capillary and electromagnetic forces.

In Chapter I, it is given the concept of stability and the analysis in tenns of normal modes technique. Moreover, we have reported the magnetohydrodynamics (MHD) basic equations and the boundary conditions. We have introduced some previous works in the hydrodynamics, magnetohydrodynamics (MHD) and gravitodynamics (GD) instability.

Chapter II, deals with the capillary gravitodynamic instability of a streaming cylindrical jet ambient with an infinite self- gravitating medium of negligible motion. The fluid jet is acted upon by the capillary, self­ gravitating, inertia and gradient pressure forces. The equilibriwn state of the model is studied and the fluid equilibrium pressure distribution is detennined. The perturbation state has been analysed and the. eigenvalue relation is derived. The latter is discussed and some limiting cases are recovered. It is found that the streaming has destablizing effects. There are stable and unstable domains. The capillary force is destabilizing only for small axisymmetric perturbation and stabilizing in the rest and idem for the self - gravitating force. However the stabilizing effect of the lat1;er could not be suppressed.