Channel size effect on drift-flux parameters for adiabatic and boiling two-phase flows
Channel size effect on drift-flux parameters for adiabatic and boiling two-phase flows
复制标题
DOI：
10.1016/j.ijheatmasstransfer.2021.122410
复制
发表时间：
2022
影响因子：
5.2
通讯作者：
T. Hibiki;Peng Ju;S. Rassame;Shuichiro Miwa;Xiuzhong Shen;Tetsuhiro Ozaki
中科院分区：
文献类型：
--
作者：
T. Hibiki;Peng Ju;S. Rassame;Shuichiro Miwa;Xiuzhong Shen;Tetsuhiro Ozaki
气液两相流被用于各种工业设备中出现的各种传热和传质过程中。典型的例子是化学反应堆，热交换器，核反应堆，除气器，冷凝器等气液两相流的数值模拟，这是高效，安全和优化的设备设计的关键，需要一个精确的模型开发的基础上的两相流体动力学的物理。双流体模型被认为是计算机模拟程序中预测两相流热工水力特性的最精确的两相守恒方程。在基于双流体模型的模拟程序中，漂移通量模型中的漂移通量参数，如分布参数和漂移速度，被用于制定界面阻力。漂移通量模型是一个有见地的模型，考虑到气体和液体速度之间的差异。通过两个漂移通量参数考虑了相和速度分布对空泡率的影响。分布参数和漂移速度是双流体模型两相流计算中的关键参数，是热工水力分析程序的核心。对于中等尺寸通道的分布参数和漂移速度的本构方程达到成熟水平，但不适用于工业尺寸通道或大尺寸通道。大尺寸通道内复杂的两相流动力学特性对分布参数和漂移速度有重要影响。在低压和低液流量条件下，由于大尺寸通道中诱导的二次流，大尺寸通道中的分布参数增加。漂移速度也增加，由于帽泡形成的表面不稳定性的大气泡。在大尺寸通道中观察到的多维两相流动力学使分布参数和漂移速度建模复杂化。因此，在大尺寸通道中的漂移通量模拟是一个更微妙的任务比在中等尺寸的通道。这一事实推动了通过模拟大尺寸通道中的分布参数和漂移速度来建立漂移通量型相关性的研究。本文的目的是提供国家的最先进的知识，在大尺寸通道的漂移通量型相关的最新发展的现状。所讨论的项目包括制定的一维漂移通量模型，典型的漂移通量的相关性开发的中型通道，过冷和饱和沸腾流的分布参数，独特的大尺寸通道中的两相流动力学，临界尺寸在中型和大型通道之间的边界，和现有的漂移通量的相关性大尺寸通道。本文讨论的流道几何形状有圆形、环形、矩形、正方形、垂直棒束和水平管束。最后对今后的研究方向进行了展望。
Gas-liquid two-phase flows are utilized in various heat and mass transfer processes that appear in numerous industrial apparatus. Typical examples are chemical reactors, heat exchangers, nuclear reactors, deaerators, condensers, etc. The numerical simulation of gas-liquid two-phase flows, which is crucial for efficient, safe, and optimized apparatus design, requires an accurate model developed based on the physics of the two-phase fluid dynamics. The two-fluid model is considered the most accurate two-phase conservation equations used in computer simulation codes to predict the thermal-hydraulic behavior of two-phase flows. The drift-flux parameters, such as the distribution parameter and drift velocity in the drift-flux model, are utilized in formulating the interfacial drag force in the two-fluid model-based simulation codes. The drift-flux model is an insightful model considering the difference between gas and liquid velocities. The effect of phase and velocity distributions on the void fraction is considered through the two drift-flux parameters. The distribution parameter and drift velocity are critical parameters in the two-phase flow formulation through the two-fluid model, which are the backbone of thermal-hydraulic analysis codes. The constitutive equations for the distribution parameter and drift velocity developed for medium-size channels reach a mature level but do not apply to industrial-size channels or large-size channels. The complicated two-phase flow dynamics in large-size channels affect the distribution parameter and drift velocity significantly. The distribution parameter in a large-size channel increases at low pressure and low liquid flow conditions due to induced secondary flow in the large-size channel. The drift velocity also increases due to cap bubbles formed by the surface instability of large bubbles. Multi-dimensional two-phase flow dynamics observed in large-size channels complicate the distribution parameter and drift velocity modeling. Thus, the drift-flux modeling in large-size channels is a much more subtle task than that in medium-size channels. This fact has driven the research to establish the drift-flux type correlations by modeling the distribution parameter and drift velocity in large-size channels. The current paper aims to provide state-of-the-art knowledge of the current status of the recent development of the drift-flux type correlations in large-size channels. The discussed items cover the formulation of the one-dimensional drift-flux model, typical drift-flux correlations developed for medium-size channels, distribution parameters for subcooled and saturated boiling flows, unique two-phase flow dynamics in large-size channels, critical size at the boundary between medium and large-size channels, and existing drift-flux correlations for large-size channels. The flow channel geometries discussed in the current paper are circular, annulus, rectangular, square, vertical rod bundle, and horizontal tube bundle. The future research direction is also discussed.