STUDY OF BIFURCATION OF ROTATING FLOW IN A CLOSED SPACE AND ITS EFFECTS ON THE PARTICLE MOTION IN THE FLOW

封闭空间旋转流分叉及其对流动中颗粒运动的影响研究

• 批准号: 13650198
• 负责人: NAKAMURA Ikuo
• 金额: $ 2.37万
• 依托单位: MEIJO UNIVERSITY
• 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-13650198/
• 关键词: ROTATING FLOW; ROTATING DISC; COMPUTATIONAL FLUID DYNAMICS; REYNOLDS NUMBER; PARTICLE MOTION; VISUALIZATION

Rotating flow field is important for pure fluid mechanics but also for engineering problems and environmental problems. As a rotating flow paradigm, flow field in a closed vessel are investigated many years from various points of view but still many questions are remained to be clarified. In this research, two types of rotating flow are studied, one is Benjamin flow, that is Taylor vortex flow in finite length and the another is rotating disc flow. For Benjamin flow, we studied using numerical and experimental methods. Specifically, Nonlinear development of flow patterns in the case of decelerating cylinder is carefully calculated and details of bifurcation process is obtained. The comparison is made between an experiment, and the calculated results and excellent agreement is obtained. But in some cases bifurcation process is more complicated in the experiment. An important controversial point is to determine the flow pattern objectively from the computed results. We constructed a program which can clarify complicated formation process of Taylor vortex using artificial intelligence technique so we can classify various flow pattern without subjective knowledge. As the first step to analyze the motion of particles in rotating flow, an orbit of fluid particle is pursued using Runge Kutta scheme of which is written in JAVA and convenient GUI system is constructed. An experimental facility is made for flow visualization for the flow induced by a rotating disc in an enclosure. Aluminum powder method is used for visualization and flow field photographed by video camera recorder and analyzed by a graphic software. Regimes of flow field are classified according to increasing Reynolds number defined by the diameter of the rotating disc and peripheral velocity of it.

旋转流场不仅对纯流体力学有重要意义，而且对工程问题和环境问题也有重要意义。作为一种旋转流的研究范式，人们从不同的角度对密闭容器内的流场进行了多年的研究，但仍有许多问题有待解决。本文研究了两种类型的旋转流动，一种是本杰明流，即有限长度的泰勒涡流，另一种是旋转圆盘流。对于Benjamin流，我们采用数值和实验相结合的方法进行了研究。详细计算了圆柱减速时流型的非线性发展，得到了分叉过程的细节。并将实验结果与计算结果进行了比较，两者吻合良好.但在某些情况下，分叉过程在实验中更为复杂。一个重要的争论点是如何从计算结果中客观地确定流型。本文利用人工智能技术编制了一个程序，可以对复杂的泰勒涡的形成过程进行解析，从而在没有主观知识的情况下对各种流型进行分类。作为分析旋转流中颗粒运动的第一步，本文采用JAVA语言编写的Runge Kutta格式对流体颗粒的运动轨迹进行了求解，并构造了方便的GUI系统。本文介绍了一种封闭空间内旋转圆盘诱导流动显示的实验装置。流场显示采用铝粉法，用摄像机拍摄流场，用图形软件进行分析。流场的区域是根据增加的雷诺数定义的旋转盘的直径和圆周速度的。

项目成果

T. Watanabe, H. Furukawa and I. Nakamura: "Nonlinear development of flow patterns in an annulus with decelerating inner cylinder"Physics of Fluid. Vol. 14-1. 333-341 (2002)

T. Watanabe、H. Furukawa 和 I. Nakamura：“具有减速内筒的环形空间中流动模式的非线性发展”流体物理学。

H. Furukawa, T. Watanabe, Y. Toya and I. Nakamura: "Flow pattern exchange in the Taylor-Couette system with a very small aspect ratio"Physical Review E, Part 2 of B. Vol. 65-3-2R. 036306-1-036306-7 (2002)

H. Furukawa、T. Watanabe、Y. Toya 和 I. Nakamura：“具有非常小的纵横比的 Taylor-Couette 系统中的流动模式交换”物理评论 E，B. Vol 的第 2 部分。

Y.Toya, I.Nakamura: "Instability of Two-Fluid Taylor Vortex Flow in the Case of An Asymmetric System"Proc. 12th Int. Couette-taylor Workshop IL USA. 2C-1. 1-4 (2001)

Y.Toya，I.Nakamura：“不对称系统情况下二流体泰勒涡流的不稳定性”Proc。

H.Furukawa, T.Watanabe, Y.Toya, I.Nakamura: "Flow pattern exchange in the Taylor-Couette system with a very small aspect ratio"Physical Review E, Part 2 of B. Vol.65 No.3-2B. 036306-036306-7 (2002)

H.Furukawa、T.Watanabe、Y.Toya、I.Nakamura：“具有非常小的纵横比的 Taylor-Couette 系统中的流动模式交换”Physical Review E，第 2 部分 B. Vol.65 No.3-2B

N.Umemura, T.Watanabe, H.Furukawa, J.Nakamura: "Visual Numerical Three-Dimmensional Flow Development between Very Short Rotating Cylinders"Proc. The 10^<th> Int. Symp. on Flow Visualization, Aug. 26-29, Kyoto.. F0095(CD-ROM). 1-10 (2002)

N.Umemura、T.Watanabe、H.Furukawa、J.Nakamura：“极短旋转圆柱体之间的视觉数值三维流动发展”Proc。