压力旋流式喷嘴喷淋液膜区换热过程的数值模拟

发布时间：2018-06-23 09:04

本文选题：喷嘴 + 流体力学　；参考：《化工学报》2017年02期

【摘要】：利用Fluent软件对压力旋流式喷嘴的内外流场进行了数值模拟,以等效的二维网格模型模拟圆周对称的三维流动,多相流和湍流模型分别采用VOF和雷诺应力模型。在两种条件下,对喷嘴流场进行模拟:1气相为空气,不发生相间热质传递;2气相为饱和水蒸气,发生相间热质传递。相变模型采取Fluent中内嵌的Lee模型。将数值模拟结果同实验结果进行对比,并以数值模拟的数据对喷嘴内外流场展开分析。模拟结果显示,由于液相在喷嘴旋流室内的螺旋运动,导致喷嘴内部形成"空气芯",液相速度在喷嘴旋流室与收缩段的连接处变化剧烈;另外,发生相间热质传递条件下,流场的压力要整体稍低且速度场的速度最大值更大;液膜的传热系数沿液膜流动方向不断减小;因气相冷凝使得液膜厚度更大,液膜破碎长度也因蒸气冷凝而变得更长。
[Abstract]:The internal and external flow field of the pressure swirl nozzle was numerically simulated by fluent software. The equivalent two-dimensional grid model was used to simulate the circular symmetric three-dimensional flow, and the VOF and Reynolds stress models were used to simulate the multiphase flow and turbulence respectively. Under the two conditions, the flow field of the nozzle is simulated in the presence of air, no heat and mass transfer between phases and saturated water vapor, and heat and mass transfer between phases. The phase change model adopts the Lee model embedded in fluent. The numerical simulation results are compared with the experimental results, and the flow field inside and outside the nozzle is analyzed with the numerical simulation data. The simulation results show that due to the spiral movement of liquid phase in the swirl chamber of the nozzle, the "air core" is formed inside the nozzle, and the velocity of the liquid phase changes dramatically at the junction between the swirl chamber and the contraction section of the nozzle. In addition, under the condition of interphase heat and mass transfer, The pressure of the flow field is a little lower and the maximum velocity of the velocity field is larger; the heat transfer coefficient of the liquid film decreases continuously along the flow direction of the liquid film; the thickness of the liquid film is larger because of the gas phase condensation, and the broken length of the film becomes longer because of the vapor condensation.
【作者单位】：天津大学化工学院;天津大学化学工程研究所;化学工程联合国家重点实验室;
【基金】：国家自然科学基金项目(21676183)~~
【分类号】：TQ021.3

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