Elucidation and control of turbulence-driven secondary flow in a rectangular duct using nonlinear traveling-wave solutions

使用非线性行波解决方案阐明和控制矩形管道中湍流驱动的二次流

• 批准号: 22360079
• 负责人: KAWAHARA Genta
• 金额: $ 12.48万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22360079/
• 关键词: 乱流; 壁乱流; 矩形ダクト; 定常進行波解; 二次流れ; 乱流遷移; 乱流パフ; 乱流斑点; 短形ダクト; 国際情報交換(ドイツ:スペイン:カナダ)

In this study, numerical computation of nonlinear traveling-wave solutions has been performed using a Newton method in a square duct. We have succeeded in obtaining the steady traveling-wave solutionexhibiting an eight-vortex pattern similar to the turbulence-driven mean secondary flow. The streamwise-averaged velocity field of this traveling wave has a comparable intensity of the time- and streamwise-averaged turbulent velocity field, and in low-Reynolds-number range, Re=1400-2500, the traveling wave reproduces not only qualitative but also quantitative properties of turbulence-driven mean secondary flow. We have also worked on numerical computation of nonlinear-traveling waves in a rectangular duct. The eight-vortex traveling wave found in a square duct has been tracked with changing anaspect ratio of a duct cross-section. It has been found that at Re=1200, the eight-vortex traveling wave exists only for the aspect ratio smaller than 2.4. It has also been observed that when the aspect ratio is increased from unity, vertical structures in the traveling wave are localized around the bisector of the duct wall of wider span. Direct numerical simulations of turbulent square-duct flow have been performed at higher Reynolds numbers, Re=3500, 5480, to identify large-scale streamwise rolls by using the Clebsch potential for cross-stream turbulence motion. It has been suggested that the large-scale rolls of a variety of cross-stream length scales play a significant role in the generation of the mean secondary flow in high-Reynolds-number turbulence.

在这项研究中，数值计算的非线性行波解已进行了使用牛顿法在方形管道。我们成功地得到了稳定的行波解，它表现出类似于连续性驱动的平均二次流的八涡模式。该行波的流向平均速度场具有与时间和流向平均湍流速度场相当的强度，并且在低雷诺数范围内，Re=1400-2500，行波再现了连续性驱动的平均二次流的定性和定量特性。我们还对矩形管道中的非线性行波进行了数值计算。本文对方形管道中的八涡行波随管道横截面长宽比的变化进行了跟踪。已经发现，在Re=1200时，八涡行波仅存在于纵横比小于2.4时。还观察到，当纵横比从1增加时，行波中的垂直结构局限于更宽跨度的管道壁的平分线周围。在较高的雷诺数Re=3500，5480，直接数值模拟的湍流方管流，以确定大规模的流向滚动使用的交叉流湍流运动的Clebsch潜力。有人认为，各种横流长度尺度的大尺度卷在高雷诺数湍流中平均二次流的产生中起着重要的作用。

项目成果

乱流中の多重スケール秩序構造の生成過程

湍流中多尺度有序结构的生成过程

• 发表时间: 2013
• 作者: H. Suzuki;K. Nagata;Y. Sakai and R. Ukai;亀谷知宏，松田佑，江上泰広，山口浩樹，新美智秀;後藤晋，河原源太，安田達哉
• 通讯作者: 後藤晋，河原源太，安田達哉

正方形ダクトにおける乱流構造と二次流れ

方管内紊流结构及二次流

• 发表时间: 2012
• 作者: Y. Hagiwara;H. Fujii and A. Kitagawa;河原源太，中辻竜也，清水雅樹，ウルマン マルクス，ピネリ アルフレド
• 通讯作者: 河原源太，中辻竜也，清水雅樹，ウルマン マルクス，ピネリ アルフレド

円管内乱流パフの分裂

圆管内湍流烟团的破碎

• 发表时间: 2012
• 作者: T. Naito;T. Watanabe;Y. Sakai;K. Nagata;Y. Ito and O. Terashima;亀谷知宏;清水雅樹，P. Manneville，Y. Duguet，河原源太
• 通讯作者: 清水雅樹，P. Manneville，Y. Duguet，河原源太

双曲型淀み点流に生じる発達した乱流のLES

双曲驻点流中发生的发达湍流的 LES

• 发表时间: 2012
• 作者: Hongwei PENG;Baolu SHI;Daisuke SHIMOKURI;Satoru ISHIZUKA1;秋山輝和,角田直人;安田達哉，河原源太，後藤晋
• 通讯作者: 安田達哉，河原源太，後藤晋

Ten Chapters in Turbulence (Capter 6 Dynamics of Wall-Bounded Turbulence)

湍流十章（第 6 章壁面湍流动力学）

• 发表时间: 2012
• 作者: J. Jimenez;G. Kawahara
• 通讯作者: G. Kawahara