Analysis of rheological properties of fibre suspensions in a Newtonian fluid by direct fibre simulation. Part 2: Flexible fibre suspensions

✍ Scribed by Mikio Yamanoi; João Maia; Tae-soo Kwak

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 424 KB
• Volume: 165
• Category: Article
• ISSN: 0377-0257
• DOI: 10.1016/j.jnnfm.2010.05.004

✦ Synopsis

Flexible fibre suspensions in a Newtonian fluid experimentally show shear-thinning and normal stress differences in steady state. This paper discusses properties of the shear viscosity, Á, and the first and second normal stresses, N 1 and N 2 , using the help of direct fibre simulation based on PSM (particle simulation method), considering near-field hydrodynamic interactions, collision without attractively interacting forces and friction forces between fibres. The software reproduces the tendencies obtained experimentally such as shear-thinning and decreasing N 1 . In addition to this result, when the aspect ratio is low (<10) and the volume fraction varies between v = 0.05 and 0.1, shear-thickening and increasing N 1 are predicted. These tendencies are analyzed using the orientation of the end-to-end vector and the radius of gyration. The prediction of N 2 as a function of ˙ is also shown in the paper.