水下高温排气两相流中流动传热特性耦合研究  

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

作　　者：林群青 宣益民[1] 韩玉阁[1] LIN Qun-Qing;XUAN Yi-Min;HAN Yu-Ge(School of Energy and Power Engineering,Nanjing University of Science&Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,南京210094

出　　处：《工程热物理学报》2020年第10期2554-2560,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51906108)。

摘　　要：通气管航行状态下水下航行器向海中排入高温废气,其实质属于气液两相流问题,该物理过程导致海面形成可探测特征.因此,弄清水下排气两相流流动传热规律,对水下航行器的探测识别具有重要价值.本文基于欧拉-欧拉双流体模型,采用适用于多尺度气泡流动的Tomiyama气液相间曳力系数、升力系数和传热系数模型,建立水下排气两相流的流动传热耦合模型,探究排气温度和速度对两相流流动传热性质的影响。结果表明:气相体积分数分布计算结果与水下排气实测结果一致,气相体积分数在深度方向呈现周期性起伏变化规律,且该起伏变化频率随排气温度和速度的降低而增大;混合相温度随排气温度升高而升高;两相流热扩散能力随排气速度的降低而降低.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.

关 键 词：水下排气 气液两相流 流动传热 欧拉-欧拉模型 

分 类 号：TV131.4[水利工程—水力学及河流动力学]