ANALYTIC-EXPRESSION FOR TAYLOR-COUETTE STABILITY BOUNDARY

We analyze the mechanism that determines the boundary of stability in Taylor-Couette flow. By simple physical argument we derive an analytic expression to approximate the stability line for all radius ratios an d all speed ratios, for co- and counterrotating cylinders. The express ion includes viscosity and so generalizes Rayleigh's criterion. We ach ieve agreement with linear stability theory and with experiments in th e whole parameter space. Explicit formulae are given for limiting case s. (C) 1996 American Institute of Physics.