Critical outflow of a vapor–liquid flow through a grain layer

Based on previous experimental studies, we carried out a numerical simulation of the process of the critical outflow of a vapor–liquid flow in cylindrical channels filled with a layer of spherical particles. The process is characterized by a sharp boiling up of the liquid and a change in the thermohydraulic properties of the flow. The spherical fillings were particles $2$, $4$, and $8$ mm in diameter, and the layer lengths were $250$ and $355$ mm. The effect of the material and the temperature of the filling on the intensification of vaporization and the profiles of the vapor content over the channel cross section were studied. Data were obtained on the critical flow rate, the speed of sound for various system configurations with respect to the particle diameter, the length of the layer of spherical particles, their material, and the level of the initial vapor content. The speed of sound is estimated for the gasdynamic blocking of a vapor–liquid flow, the values of which are in the region between the thermodynamically equilibrium and the frozen speeds of sound.