The loss of stability in ground based experiments in liquid bridges

In this study our primary goal is to investigate the loss of stability of t he steady convection in deformable liquid bridges. Definitely, the deformat ion plays an important role in the transition process from the steady axisy mmetric 2-D basic state to the 3-D periodical one. As it was shown experime ntally by many researchers, the critical Marangoni number is very sensitive to the Volume of liquid. It seems to be proved(1-4), that the critical wave number for high Prandtl fluids (for example, silicone oil of different viscosities, Pr > 50) is m = 1 for aspect ratios Gamma = height/radius greater than or equal to 1.0 reg ardless of the free surface shape. But the data from our last experiments s how, that by changing surrounding conditions around the liquid bridge we ca n change the critical wave number. Particularly, by placing the liquid brid ge of diameter 2r = 6 mm into another cylindrical volume of the diameter 2R = 12 mm kept at constant temperature, the critical mode is switched from m = 1 to m = 2. (C) 1999 Elsevier Science Ltd. All rights reserved.