ENERGY STABILITY OF THERMOCAPILLARY CONVECTION IN A MODEL OF THE FLOAT-ZONE CRYSTAL-GROWTH PROCESS

Energy stability theory has been applied to a basic state of thermocapillary convection occurring in a cylindrical half-zone of finite length to determine conditions under which the flow will be stable. Because of the finite length of the zone, the basic state must be determined numerically. Instead of obtaining stability criteria by solving the related Euler—Lagrange equations, the variational problem is attacked directly by discretization of the integrals in the energy identity using finite difference’s. Results of the analysis are values of the Marangoni number, MaE, below which axisymmetric disturbances to the basic state will decay, for various values of the other parameters governing the problem. © 1990, Cambridge University Press. All rights reserved.