Numerical study on the evolution characteristics of phase interface of subsonic and sonic steam jets in transverse subcooled flow

Abstract

The cooling process of high-temperature steam ejecting into subcooled liquid widely exists in industrial production, with high mass and heat transfer efficiency. This paper establishes an unsteady numerical simulation method for jet condensation based on the two-fluid model and the thermal phase change model, focusing on the phase interface evolution and pressure fluctuation characteristics of steam jets in the crossflow of subcooled water under different mass fluxes. With the increase of mass flux, the ability of the jet plume to resist water flow is enhanced; thus, the heat and mass transfer at the two-phase interface becomes more stable; the length of the plume increases, and the range of oscillation of the plume length in the axial direction and the radial direction decreases. The pressure vortex that generated by the two-phase region and the subcooled water is more stable with reduced total pressure fluctuations. Under subsonic conditions, bubbles are shed on the leeward side, and the ranges of axial oscillation, radial oscillation and total pressure oscillation are 1.57de–3.41de, 0.21de–0.37de, and 0.17de–0.32de, respectively. The steam plume becomes progressively longer in the axial direction as the steam velocity increases from subsonic to sonic and supersonic speeds, and the range of interfacial oscillations and total pressure fluctuations along the radial direction are further reduced. Under the same working condition, with the increase of axial distance, the momentum of the steam jet decreases, the ability to resist the impact of water flow decreases, and the windward side is greatly affected; the axial and radial amplitude fluctuations of the pressure increases, with the amplitude on the windward side being significantly larger than that on the leeward side, and the maximum difference between the fluctuations on both sides increases continuously. The momentum change of the two-phase interface is intense, which is the main factor of pressure fluctuation. The correlation coefficients of pressure oscillation with radial and axial interface oscillations are 0.9110 and 0.7477, respectively.