Studies of instability of two-phase flows in parallel channels

Experiments were carried out to determine boundaries of unsteady-state flows of a two-phase water-air mixture in three parallel vertical channels. It is shown that under certain conditions of parallel operation of individual channels self-sustained fluctuations of the pressure drop can appear and that interchannel interations can lead to unstable two-phase flow regimes with stable hydrodynamic characteristics of the individual channels and the whole system. It is shown that these fluctuations are caused by nonlinear characteristics of the two-phase flow.