Vibroprotection as a method of reducing transport losses of cryogenic liquids

Abstract

62-752:621.642.2 and M. V. MatyukhinaThe losses of cryogenic liquids, especially helium and nitrogen, in testing vessels in vibrostands increase by a factor of five or more [i, 2], and in transporting containers on roads they increase 5-8 times with the increase of the travel speed of the vehicle and reduc ~ tion of the quality of roads [3].The mechanism of the increases of these losses has been studied insufficiently.It is assumed in [3] that the increase of the losses is caused by the dissipation of the energy of oscillations of the liquid caused by its viscous properties.However, the calculated dissipative fraction of the process was considerably smaller than the experimental value. The reason for the difference has not been explained.We assume that in addition to the dissipative fraction, there are fractions of the losses caused by vapor formation in the layers of the liquid during oscillations of the vibrator (walls and bottom of the vessel).The metallic walls and bottom of the vessel which are in contact with the liquid rupture the intermolecular bonds in the adjacent layer of the liquid. This causes the formation of vapors without the supply of thermal energy tothe layer (only mechanical energy supply).It is evident that the physical reason for this process is acoustic cavitation [4].If the mass of the oscillating liquid, the mean amplitude of the oscillation of the liquid in respect to the volume, and the forced frequency are known, the mechanical (kinetic) energy (the energy of forced oscillations) supplied to the liquid is W~'~ T o --~ 4~The total calculated power which corresponds to the increase of the losses and is transferred to the liquid is