Abstract
A study has been made on the formation of accretion during submerged gas injection into liquid. Cooled nitrogen or helium gas was injected into a water bath or an acetic acid bath through an orifice of 0.1-0.15 cm in diameter located at the vessel bottom made of polyvinyl chloride. Gas jets and accretions were photographed. The strength of the vibration of the vessel were measured by an accelerometer.
In the sonic flow region, a porous cylindrical accretion with a hollow central core was formed. In the subsonic flow region, a porous hemispherical accretion without the central core was observed to form. The vibration of the vessel decreased abruptly when the accretion began to form. The gas and liquid temperatures and the gas flow velocity were found to be determining factors for the critical condition obtained experimentally for the initiation of the accretion. The critical condition was explained reasonably on the basis of a heat transfer model around the orifice exit.
