多力场耦合条件下T型圆管通道内流体热混合机理研究  

Research on the Thermal Mixing Mechanism of Fluids in a Circular T-Junction under Multi-Force Field Coupling Conditions

作　　者：李桉琦 苏博 林梅[1] 王秋旺[1] LI Anqi;SU Bo;LIN Mei;WANG Qiuwang(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2025年第1期78-92,共15页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51976159)。

摘　　要：针对海洋动力平台和船舶动力装置中T型圆管通道内冷热流体间的热混合机理尚不清楚的问题,利用大涡模拟方法,对不同支管布置方式高温高压工况下(运行压力为10 MPa,进口流体温差为275 K,摇摆雷诺数为41 500)的多力场耦合T型圆管通道内流体热混合机理进行数值研究。利用提出的混合系数定量评价了不同布置方式下T型圆管通道内流体混合效果,利用均方根温度定量评价了不同布置方式下T型圆管通道管壁处温度脉动情况。结果表明:剪切层和尾迹区内涡结构与温度场存在时间和空间上的协同机制,且涡脱落频率和温度脉动频率基本相同,脱落频率为19.3 Hz;附加惯性力引起T型圆管通道内涡结构和温度场在时间和空间上周期性变化,加速了流体混合过程,削弱了浮升力和重力引起的热分层现象,同时增大了流体域内温度波动,长度约为10.2 D(D为主管内径);与对应的静止工况相比,支管竖直向上、水平和竖直向下布置时,摇摆条件下混合系数分别增大了10.8%、18.3%和27.8%;摇摆条件竖直向下布置时,管壁处温度均方根峰值最大为0.16,约为静止工况的2倍。因此,支管竖直向上布置时,热混合效果最好,热分层现象最弱,在实际应用中应被优先考虑。In response to the unclear thermal mixing mechanism between hot and cold fluids in the circular T-junctions of marine power platforms and ship power devices,the large eddy simulation method is employed to investigate fluid thermal mixing under high temperature and high pressure conditions.This study examines different branch pipe arrangements with a working pressure of 10 MPa,an inlet fluid temperature difference of 275 K,and a swing Reynolds number of 41500,all under multi-force field coupling conditions.The proposed mixing coefficient is employed to quantitatively assess the fluid mixing effect within the circular T-junction,while the root mean square temperature is used to evaluate temperature fluctuations at the wall of the circular T-junction,under different branch pipe configurations.The results reveal a temporal and spatial synergistic mechanism between the vortex structure and temperature field in the shear layer and wake region.Notably,the vortex shedding frequency aligns closely with the temperature fluctuation frequency at corresponding positions,with a shedding frequency of 19.3 Hz.The additional inertial force induces periodic changes in both the vortex structure and temperature field within the circular T-junction,accelerating the fluid mixing process.This effect mitigates the thermal stratification phenomenon caused by buoyancy and gravity,resulting in increased temperature fluctuations in the fluid domain,with a characteristic length of approximately 10.2 D.Compared to static conditions,mixing coefficients increase by 10.8%,18.3%,and 27.8%for branch pipes arranged vertically upwards,horizontally,and vertically downwards under swing conditions,respectively.The maximum peak of the root mean square temperature for T-junctions arranged vertically downwards under swinging conditions reaches 0.16,approximately double that of stationary conditions.Therefore,when branch pipes are arranged vertically upwards,the thermal mixing effect is optimal,and thermal stratification is minimized,making this arrangemen

关 键 词：T型圆管通道 浮升力 摇摆条件 热混合机理 大涡模拟 

分 类 号：TK121[动力工程及工程热物理—工程热物理]