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Clarification of Boiling Complexity and Modeling - Approach based on Nonlinear Dynamics -

澄清沸腾复杂性和建模 - 基于非线性动力学的方法 -

基本信息

批准号：
12450081
负责人：
SHOJI Masahiro
金额：
$ 10.62万
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 (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

With aims of making clear the complexity and nonlinear characteristics of boiling, five parallel studies were performed for pool and forced convection boiling. Namely, in 2002, The experiments of (1) boiling on an heated surface with an artificial cavity, (2) Bubble formation from an orifice in air-water isothermal system, (3) Interaction between twin bubbles generated from two neighboring orifices, (4) Nonlinear characteristics and identification of two-phase flow patterns, (5) Phase separation and fluctuation characteristics of two-phase flow impacting at a T-junction. In every experiment, nonlinear chaos theory was employed to analyze the data and have obtained interesting and valuable results. In the experiment of (1), it is found that cylindrical cavity is most stable among conical, cylindrical and entrained cavities. In the study of (3), it is found that the critical gas flow rate exists in the system. These are the new findings not ever known. These results have been published in the academic journals as well as National and international conferences. In 2001, the studies of (3)-(6) were continued to study, and in addition, basing on the results of experiment (1), new experimental study in which a single cavity, twin cavities and multiple cavities was started. In the study using a single cavity, the effects of cavity size (diameter and the depth of the cavity) to the boiling features were investigated in detail. In the study using twin cavities, nucleation site interaction was discussed. In the experiment employing multiple cavities, heat transfer characteristics were studied. Together with above experimental studies, modeling was tried for the bubble dynamics and two-phase flow pattern to show that there exists low dimensional chaos in pool boiling and two phase flow.

为了阐明沸腾的复杂性和非线性特征，对池沸腾和强制对流沸腾进行了五项平行研究。即2002年，进行了以下实验：（1）人工空腔加热表面沸腾；（2）气水等温系统中孔口形成气泡；（3）相邻两个孔口产生的孪生气泡相互作用；（4）两相流流型的非线性特性及识别；（5）两相流冲击时的相分离与脉动特性实验。 T 形接头。在每个实验中，都采用非线性混沌理论来分析数据，并获得了有趣且有价值的结果。在(1)的实验中发现，圆锥形、圆柱形和夹带型腔中，圆柱形腔最稳定。在(3)的研究中，发现系统中存在临界气体流量。这些都是未知的新发现。这些成果已发表在学术期刊以及国内和国际会议上。 2001年，继续研究(3)-(6)的研究，此外，在实验(1)的结果的基础上，开始了单腔、双腔和多腔的新实验研究。在使用单个空腔的研究中，详细研究了空腔尺寸（空腔的直径和深度）对沸腾特征的影响。在使用双腔的研究中，讨论了成核位点的相互作用。在使用多个腔体的实验中，研究了传热特性。结合上述实验研究，尝试对气泡动力学和两相流模式进行建模，以表明池沸腾和两相流中存在低维混沌。