Author(s)

C.T. Nguyen, H. Bazzi & N. Galanis

Abstract

Unstable thermocapillary flow inside a float zone C. T. Nguyen', H. Bazzi* & N. Galanis^ * School of Engineering, Universite de Moncton (N. B.), Canada. ^Faculty of Engineering, Universite de Sherbrooke (Quebec), Canada. Abstract In this study, we have numerically investigated the problem of the transition from an axisymmetric state to an unstable i.e. oscillatory state in a liquid float zone which is held suspended between a pair of coaxial disks. The system of governing equations corresponding to a time-dependent-3D model was successfully solved by employing the modified-SIMPLE method. Results have shown that for a low Marangoni number, the flow consists of a steady, axisymmetric and toroidal structure exhibiting a 'purely' axial fluid circulation on the free surface. The vortex center is observed beneath that surface near the hot disk. When the Marangoni number increases beyond the critical value MacR, MacR« 9750, the transition to an oscillatory state occurs. The flow and the t

Keywords