Critical flow rate and velocity of a multiphase continuum

Considering the continuum model of multiphase flow the condition of flow crisis appearance as a mode with infinite pressure gradient is obtained. Criticality condition connects the velocities and internal energies of phase with continuum pressure and medium adiabate index. On the basis of thermodynamic ratios the index of continuum adiabate is found, which can be calculated from entropy formulas at high pressure gradients. Three-velocity, three-temperature model of gas-liquid flow are considered. The model is completed using the known and recently obtained ratios for the calculation of dynamic and thermal discrepancy of phases. Calculated and experimental values for critical velocities and flow rates of gas-liquid, air-water and steam-water flows are compared