Direct numerical simulation of oscillatory Marangoni convection, in cylindrical liquid bridges

A three-dimensional oscillatory Marangoni (thermocapillary) convection with Prandtl number Pr = 16.0849 and Marangoni number Ma = 3.30508 x 10(4) in a large aspect ratio (As = H/R) range, As = 0.2-4, in a silicone oil liquid bridge with a non-deformable cylindrical surface is investigated by the fin ite volume method. The azimuthal wave numbers 1, 2, 3, 4, 5, 6, 10 and 16 a re obtained for different aspect ratios, As. The dimensionless main frequen cy f(p)* = f Ma(-1/2)H(2)/kappa of periodic or quasi-periodic temperature o scillations strongly depends on aspect ratio, As. f(p)* increases with the increment of As with approximately a bi-linear relation, and its gradient f or As = 0.2-1 is less than that for As > 1. The periodic and quasi-periodic oscillations are found to depend on aspect ratio, As, for fixed Pr and Ma. (C) 1999 Elsevier Science B.V. All rights reserved.