Influence of initial conditions in low-pressure chamber on the degree of expansion of the boiling liquid nitrogen jet

The dynamics of boiling a cryogenic nitrogen jet flowing through a thin conical nozzle into a vacuum chamber from a high-pressure vessel has been studied. To describe the process, a spatial axisymmetric two-phase model of a vapor-liquid mixture is proposed in a two-temperature, two-velocity, one-pressure approximations, taking into account nonequilibrium evaporation and condensation processes. The rate of mass transfer depends on number and radius of bubbles, degree of overheating in temperature, heat of vaporization, thermal conductivity coefficient and the Nusselt and Jacob numbers. The formation modes of jet flow velocity fields are studied and quantitative estimates of the spray angle magnitude in the jet are obtained depending on the initial pressure in the vacuum chamber. The reliability of the obtained results is estimated by comparison with experimental data.