Numerical Analysis of Droplet Flow Regime in Gas-Liquid Two-Phase Flow using Particle Method

气液两相流中液滴流态的粒子法数值分析

• 批准号: 13650167
• 负责人: KOSHIZUKA Seiichi
• 金额: $ 2.62万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650167/
• 关键词: Gas-liquid two-phase flow; Droplet; Surface tension; Numerical analysis; Particle method; Critical Weber number; Interfacial area; MPS method; 気液三相流; ドライアウト; 沸騰遷移; 液滴の分裂; 液滴流; 臨界ウエーバー数

Two-fluid model has been used for gas-liquid two-phase flow analysis. Governing equations of gas and liquid phases are simultaneously solved with correlations expressing interfacial interactions. These correlations are obtained by experiments. Numerical analysis is difficult for them. In particular, interfacial area is an important parameter to determine the interactions. Grids are not necessary in particle method, so that fragmentation and coalescence of fluids as well as large deformation of interfaces can be analyzed. In the present study, the critical Weber number by which the interfacial area is evaluated in the droplet flow regime is analyzed by the particle method.The particle method used here is MPS (Moving Particle Semi-implicit) method which has been developed by the present researcher. A new model for surface tension is developed to analyze single droplet behavior. Vibration of a square droplet is calculated and the oscillating period agrees with that of the analytical solution. Flow around a droplet is calculated and the pressure distribution on the droplet agrees with those of the past studies. Droplet breakup is driven by the pressure distribution and suppressed by surface tension. Both processes are verified. It is also clarified that more than 100 particles are necessary to analyze the droplet behavior accurately.It is known that the droplet breakup is governed by a non-dimensional number called Weber number, which is the ratio of the driving force to the suppressing force. Critical Weber number gives the limit of droplet breakup. The breakup does not occur when the Weber number is below the critical value. The droplet behavior is calculated for various Weber numbers using the MPS method. The results show that the critical Weber number is 13. This agrees with experimental data. Therefore, it is concluded that the critical Weber number is successfully analyzed by the MPS method.

两流体模型已用于气体液体两相流量分析。与表达界面相互作用的相关性同时解决了气体和液相的治疗方程。这些相关性是通过实验获得的。对于他们来说，数值分析很困难。特别是，界面区域是确定相互作用的重要参数。网格在粒子方法中不是必需的，因此可以分析流体的碎裂和合并以及界面的较大变形。在本研究中，通过粒子方法分析了在液滴流方面评估界面区域的临界韦伯数。开发了一种新的表面张力模型来分析单滴行为。计算平方液滴的振动，振荡周期与分析溶液的振动相符。计算液滴周围的流量，并与过去研究的压力分布相符。液滴破裂是由压力分布驱动的，并被表面张力抑制。两个过程均已验证。还可以澄清的是，需要100多个颗粒来准确分析液滴行为。众所周知，液滴分解受称为Weber数字的非二维数字，这是驱动力与抑制力的比率。关键的Weber数字给出了液滴分解的限制。当Weber号码低于临界值时，不会发生分解。使用MPS方法计算各种Weber数字的液滴行为。结果表明，关键的韦伯数为13。这与实验数据一致。因此，得出的结论是，通过MPS方法成功分析了关键的Weber数。

项目成果

S. Koshizuka: "Particle Method for Incompressible Flow with Free Surface"Proc. ASME 2002 Fluids Engineering Division Summer Meeting (FEDSM'02). FEDSM2002-31154. (2002)

S. Koshizuka：“自由表面不可压缩流动的粒子方法”Proc。

S.Koshizuka: "Numerical Analysis of Large Deformation of Free Surface using Particle Method"Proc. 8th Symposium on Nonlinear and Free-Surface Flows. 41-44 (2002)

S.Koshizuka：“使用粒子法对自由表面大变形进行数值分析”Proc。

K.Nomura, S.Koshizuka, Y.Oka, H.Obata: "Numerical Analysis of Droplet Breakup Behavior using Particle Method"J. Nucl. Sci. Technol.. 38(12). 1057-1064 (2001)

K.Nomura、S.Koshizuka、Y.Oka、H.Obata：“使用粒子法对液滴破裂行为进行数值分析”J。

越塚誠一: "粒子法による流れの数値解析"ながれ. 21. 230-239 (2002)

Seiichi Koshizuka：“使用粒子法进行流动的数值分析”Nagare 21. 230-239 (2002)。

R.Duan: "Numerical Simulation of Drop Breakup by MPS Method"第7回計算工学講演会論文集. 7. 691-694 (2002)

R. Duan：“MPS方法对液滴破碎的数值模拟”第七届计算工程会议论文集7. 691-694 (2002)。