Study on Flow and Heat Transfer Coupling Mechanism in Two-phase Flow of High-temperature Underwater Exhaust

The submerged bodies proceeding with snorkel exhaust high-temperature gas into the water, which is the gas-liquid two-phase flow essentially, resulting in the detectable signature on sea surface. Thus, to seek the flow and heat transfer coupling mechanism in this two-phase flow is significant for detection and recognition of submerged bodies. This paper establishes a numerical model of flow and heat transfer in the two-phase flow of high-temperature underwater exhaust, based on the Eulerian-Eulerian method and combined with the Tomiyama's drag coefficient model, buoyancy coefficient model and heat transfer coefficient model which are appropriate for multi-scale bubble flow. The influences of the exhaust temperature and velocity on the two-phase flow and heat transfer characteristics are investigated. The results show that the simulation data of gas volume fraction distribution is highly agreed with the experimental data. Additionally, a periodic variation tendency of gas volume fraction appears in the depth direction. Furthermore, the variation frequency increases with the decline of the exhaust temperature and velocity. The mixture temperature increases with the increment of the exhaust temperature. However, the thermal diffusion property of the two-phase flow is weakened with the decrease of the exhaust velocity.