A Study on the Mechanism of Reduction of Turbulence Generation in Viscoelastic Fluid

减少粘弹性流体湍流产生机理的研究

• 批准号: 16560136
• 负责人: HORIUI Kiyosi
• 金额: $ 2.18万
• 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: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560136/
• 关键词: Turbulent drag reduction; Polymer-diluted fluid; Constitutive stress equation; Direct numerical simulation; Johnson-Segalman equation; Affinity of polymer strand; Homogeneous isotropic tuebulence; Pipe flow; DNS; JS方程式; rotating-disk apparatus /

We studied the effect of non-affinity in the viscoelastic fluid on the process of the vortical structure formation and reduction of turbulence generation. We dealt with the homogeneous isotropic turbulence and the turbulence in the pipe flow, and utilized the numerical data which were generated using the direct numerical simulation method. The non-affine effect on the polymer stress was approximated using the Johnson-Segalman constitutive equation (Johnson and Segalman 1977, JS model). In both isotropic and pipe flows, the degree of reduction of the turbulence generation was not monotonic on the strength of the non-affinity. The largest reduction of turbulence generation was achieved when the non-affine effect was largest, i.e., the Oldroyd-A equation, and the smallest reduction when the non-affine effect was smallest, i.e., the Oldroyd-B equation. Mechanism of this reduction was examined by looking into the formation of the vortical structures. It was shown that the concentration of the polymer stress was largest in the tube core region in the Oldroyd-B equation and the growth of the vortex tube core region was attenuated, whereas the concentration was largest in the vortex sheet region in the Oldroyd-A equation, thus the transformation of the vortex sheet into the vortex tube was annihilated. A theoretical analysis on the JS model was carried out using the algebraic approximate steady solution of the model. It was shown that the 2^<nd>-order solution does not yield a non-monotonic growth of the turbulence generation reduction. This drawback was mitigated in the solutions with 3^<rd> or higher orders.

我们研究了非亲和力对粘弹性流体的影响对涡流结构形成和湍流产生的减少的过程。我们处理了管流中的均质各向同性湍流和湍流，并利用了使用直接数值模拟方法生成的数值数据。使用Johnson-Segalman组成方程近似对聚合物应力的非伴侣作用（Johnson and Segalman 1977，JS模型）。在各向同性和管道流中，在非亲和力的强度上，湍流产生的降低程度并不是单调的。当非伴随效应最大，即OldRoyd-A方程最大，而当非伴随效应最小时（即Oldroyd-B方程）时，湍流产生最大的减少是实现的。通过研究涡流结构的形成来检查这种还原的机制。结果表明，在Oldroyd-B方程中，聚合物应激的浓度最大，并且涡流管核区域的生长被减弱，而Oldroyd-A方程中涡流区域中的浓度最大，因此涡流纸转化为涡流管的转化。使用该模型的代数近似稳定解进行了对JS模型的理论分析。结果表明，2^<nd> - 阶溶液不会产生湍流产生减少的非单调生长。在3^<rd>或更高订单的解决方案中缓解了这一缺点。

项目成果

An identification method for vortex sheet structures in turbulent flows

湍流涡片结构的识别方法

• 发表时间: 2005
• 期刊: Phys. of Fluids 17
• 作者: Horiuti;K.;Takagi;Y.
• 通讯作者: Y.

Vortex sheet identification method and fourth-order velocity derivative invariants

涡片辨识方法及四阶速度导数不变量

• 发表时间: 2005
• 期刊: Bulletin of the American Phys.Soc. 50
• 作者: Horiuti;K.;Takagi;Y.;Fujisawa;T.
• 通讯作者: T.

一様等方乱流にたいする非アファイン粘弾性効果

对均匀各向同性湍流的非仿射粘弹性效应

• 发表时间: 2005
• 期刊: 九州大学応用力学研究所研究集会報告 17ME-S3
• 作者: 堀内潔;寺岡恒;高木洋平
• 通讯作者: 高木洋平

Assessment of the Generalized Scale-Similarity Model in Compressible Homogeneous Isotropic Turbulence

• DOI: 10.1143/jpsj.73.2732
• 发表时间: 2004-10
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: T. Itami;K. Horiuti

一様等方乱流における乱流構造形成過程とレイノルズ数依存性

均匀各向同性湍流中湍流结构形成过程和雷诺数依赖性

• 发表时间: 2005
• 期刊: 日本機械学会論文集 B編 71
• 作者: 高木洋平;堀内潔
• 通讯作者: 堀内潔