GAS-FILM LEVITATED LIQUIDS - SHAPE FLUCTUATIONS OF VISCOUS DROPS

A new, containerless method for measuring viscosity variations, as a f unction, e.g., of temperature or concentration, is described. Relative viscosities are extracted from the resonance quality factor near eige nfrequencies of deformation modes of gas-film levitated liquid drops. Both the geometrical aspect of the drop and the resonance profile are dissymmetric in general. This can be understood in terms of a parametr ic instability against nonlinear oscillations. The method could be use ful for viscosity measurements under conditions where contact with wal ls should be avoided-in particular at high temperatures, in order to a void corrosion or chemical contamination.