The International Conference on Multiphase Systems, ICMS'2000
|Downward Bubbly Flow in a Vertical Pipe|
Kashinsky O. N., Randin V. V.
Institute of Thermophysics, Novosibirsk, RUSSIA
Periodic oscillations of a air bubble in the center of a spherical volume of liquid (water) are considered. The oscillations are excited by the periodically varying pressure on the external surface of the liquid sphere. The bubble radius is small in comparison with the radius of the liquid sphere as well as the length of the external pressure wave. Maximum values of temperature, density and pressure in the bubble and the way of their attainment are examined as functions of the external excitation amplitude and the initial bubble radius. To this end, the gasdynamic equations allowing for heat-conductivity and some approximations to these equations (the homobaric approximation for the gas in the bubble, approximations of slightly compressible liquid and linear acoustics for the surrounding liquid) are utilized to simulate dynamics of the gas and the liquid. Vibrational degrees of freedom, dissociation, ionization and intermolecular forces are taken into account by the equations of state for the gas.