Effects of extensional rates on characteristic scales of two-dimensional turbulence in polymer solutions

21st Fluid Mechanics Conference

物理学;力学

Hidema, R.^1

Organization of Advanced Science and Technology, Kobe University, 1-1, Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan^1

关键词: 2d fourier transforms;    Anisotropic structure;    Extensional viscosity;    Hydroxypropyl cellulose;    Interference patterns;    Normal direction;    Turbulent drag reduction;    Two dimensional turbulence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/530/1/012065/pdf
DOI  :  10.1088/1742-6596/530/1/012065

学科分类：力学，机械学

来源: IOP

【 摘 要 】

In order to study the effects of extensional viscosities on turbulent drag reduction, experimental studies using two-dimensional turbulence have been made. Anisotropic structures and variations of energy transfer induced by polymers are considered. Polyethyleneoxide and hydroxypropyl cellulose having different flexibility, which is due to different characteristics of extensional viscosity, are added to 2D turbulence. Variations of the turbulence were visualized by interference patterns of 2D flow, and were analysed by an image processing. The effects of polymers on turbulence in the streamwise and normal directions were also analysed by 2D Fourier transform. In addition, characteristic scales in 2D turbulence were analysed by wavelet transform.