Modeling of dynamics of supercritical water jet outflowing from a thin nozzle
R.Kh. Bolotnova1, V.A. Korobchinskaya1,2
1Mavlyutov Institute of Mechanics UFRC RAS, Ufa, Russia
2Bashkir State University, Ufa, Russia
Keywords: thin nozzle, boiling water outflow, OpenFOAM package, mathematical and numerical modeling
Abstract
The fluid dynamics of a water fluid jet with supercritical state parameters outflowing from a high-pressure vessel through a thin nozzle is investigated. The numerical modeling of the jet was carried out using a system of equations for a gas-vapor-liquid mixture which includes the conservation laws for mass, momentum and energy formulated in with one-pressure, one-velocity, and two-temperature approximation. The simulation takes into account the contact heat and mass transfer processes of evaporation and condensation under equilibrium condition using a modified solver reactingTwoPhaseEulerFoam within the OpenFOAM free open package. The process of barrel shock formation in a supersonic boiling jet with developing the Mach disk is demonstrated. It was found that the outflow process is accompanied by formation of vortex zones near the jet symmetry axis and this induces periodic pulsations in pressure and mass velocity inside the jet. Finally, this generates the acoustic pulses series preceding the main jet flow. Justification of reliability for the applied numerical method implemented through the OpenFOAM package solver is offered through comparing the numerical and analytical solutions for the Sedov problem of a strong point explosion in a two-phase gas-droplet mixture (for the planar case). The comparative analysis of simulation and the experimental photography for the supersonic nitrogen jet ejected from a cylindrical nozzle of a high-pressure reservoir is presented. The numerical results obtained using the OpenFOAM package demonstrate a satisfactory agreement with analytical solution and experimental data.
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