Study on drag reduction mechanism with emphasis on non-affinity in polymer chain coil-stretch transition

以聚合物链卷曲-拉伸转变非亲和力为重点的减阻机理研究

• 批准号: 23560188
• 负责人: HORIUTI Kiyosi
• 金额: $ 3.41万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2013
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23560188/
• 关键词: 抵抗低減; 高分子添加溶液; 界面活性剤; 粘弾性流体; Brownian dynamics; Elastic dumbbell model; 反変・共変ベクトル; エネルギーカスケード; 高分子添加; ブラウ二アン力学; Elastic dumbbellモデル

We carried out numerical study to reveal the mechanism of drag reduction (DR) in polymer-diluted flows. The polymer chains are modeled as elastic dumbbells. We elucidated the effect of non-affinity in the motion of dumbbells on DR, where their motions do not precisely correspond to macroscopically-imposed deformation. The DNS for the solvent is coupled to the mesoscopic description of dumbbells using BDS in forced homogeneous isotropic turbulence. Compared with the complete affine case (a=0.0), more drastic DR is achieved when non-affinity is maximum (a=1.0). When a=0.0, the dumbbell connector vector is convected as contravariant vector representing material line element and elasticity is caused on the tubular structures. When a=1.0, the connector is convected as covariant vector representing material surface element, and directs outward perpendicularly on the planar structures and exert an extra tension on vortex sheet, which leads to attenuation of energy cascade, causing larger DR.

我们进行了数值研究，以揭示聚合物稀释流中阻力减少（DR）的机制。聚合物链被建模为弹性哑铃。我们阐明了非亲和力对哑铃运动对DR的影响，在该运动中，它们的运动并不准确地对应于宏观施加的变形。溶剂的DNS与强制均质各向同性湍流中的BDS耦合到哑铃的介质描述。与完整的仿射情况（a = 0.0）相比，当非亲密性最大（a = 1.0）时，可以实现更多剧烈的DR。当a = 0.0时，哑铃连接器矢量被认为是代表材料线元素的逆向矢量，并且在管状结构上引起弹性。当a = 1.0时，连接器将作为代表材料表面元件的协变量向量，并垂直于平面结构向外引导，并在涡旋上施加额外的张力，从而导致能量级联的衰减，从而导致较大的DR。

项目成果

Ten Chapters in Turbulence, Chapter 2

湍流十章，第二章

• 发表时间: 2013
• 作者: J. Schumacher;R. M. Kerr and K. Horiuti
• 通讯作者: R. M. Kerr and K. Horiuti

Structure and Dynamics of Vorticity in Turbulence, Chapter 2 in"Ten Chapters in Turbulence", Ed. by P. A. Davidson, Y. Kaneda and K. R. Sreenivasan

湍流中涡度的结构和动力学，《湍流十章》第二章，编辑。

• 发表时间: 2012
• 作者: J. Schumacher;R. M. Kerr and K. Horiuti
• 通讯作者: R. M. Kerr and K. Horiuti

Contravariant and covariant dumbbells in polymer-diluted viscoelastic turbulence

聚合物稀释粘弹性湍流中的逆变和协变哑铃

• 发表时间: 2013
• 作者: 青柳 渉;Ian Kesniel Panelo Esberto;茂田 正哉;伊澤 精一郎;福西 祐;K. Horiuti and S. Takeu
• 通讯作者: K. Horiuti and S. Takeu

Marked Drag Reduction in Non-affine Viscoelastic Turbulence in Homogeneous Isotropic and Pipe Flows

均质各向同性和管流中非仿射粘弹性湍流的显着减阻

• DOI: 10.1088/1742-6596/318/9/092016
• 发表时间: 2011
• 期刊: J. Phys.: Conf. Ser.
• 作者: K. Horiuti;K. Matsumoto and M. Adachi
• 通讯作者: K. Matsumoto and M. Adachi

Dumbbellモデルを用いたBDS-DNSによる乱流抵抗低減機構の解明

利用哑铃模型阐明BDS-DNS湍流减阻机制

• 发表时间: 2011
• 作者: 松本 一真; 堀内 潔
• 通讯作者: 堀内 潔