Titlebar

Export bibliographic data
Literature by the same author
plus on the publication server
plus at Google Scholar

 

Thixotropy in macroscopic suspensions of spheres

DOI zum Zitieren dieses Dokuments: https://doi.org/10.1103/PhysRevE.65.051402
URN to cite this document: urn:nbn:de:bvb:703-epub-4027-2

Title data

Völtz, Camilla ; Nitschke, M. ; Heymann, Lutz ; Rehberg, Ingo:
Thixotropy in macroscopic suspensions of spheres.
In: Physical Review E. Vol. 65 (2002) . - no. 051402.
ISSN 1550-2376
DOI: https://doi.org/10.1103/PhysRevE.65.051402

[img] PDF
PhysRevE.65.051402.pdf - Published Version
Available under License Deutsches Urheberrechtsgesetz .

Download (208kB)

Abstract

An experimental study of the viscosity of a macroscopic suspension, i.e., a suspension for which Brownian motion can be neglected, under steady shear is presented. The suspension is prepared with a high packing fraction and is density matched in a Newtonian carrier fluid. The viscosity of the suspension depends on the shear rate and the time of shearing. It is shown that a macroscopic suspension shows thixotropic viscosity, i.e., shear thinning with a long relaxation time as a unique function of shear. The relaxation times show a systematic decrease with increasing shear rate. These relaxation times are larger when decreasing the shear rates, compared to those observed after increasing the shear. The time scales involved are about 10000 times larger than the viscous time scale τvisc=a2/ν and about 1000 times smaller than the thermodynamic time scale τtherm=Pe/˙γ. (a is the gap width of the viscometer, ν is the kinematic viscosity, Pe=6πη˙γτ)3/(kBT) is the Péclet number and ˙γ is the shear rate.) The structure of the suspension at the outer cylinder of a viscometer is monitored with a camera, showing the formation of a hexagonal structure. The temporal decrease of the viscosity under shear coincides with the formation of this hexagonal pattern.

Further data

Item Type: Article in a journal
Keywords: Shear rate dependent viscosity; Shear rate dependent structure (shear thinning and shear thickening); Emulsions and suspensions; Non-Newtonian fluid flows.
DDC Subjects: 500 Science > 530 Physics
600 Technology, medicine, applied sciences > 620 Engineering
Institutions of the University: Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics V
Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics V > Chair Experimental Physics V - Univ.-Prof. Dr. Ingo Rehberg
Faculties > Faculty of Engineering Science > Chair Technical Mechanics and Fluid Mechanics
Faculties
Faculties > Faculty of Mathematics, Physics und Computer Science
Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics
Faculties > Faculty of Engineering Science
Language: English
Originates at UBT: Yes
URN: urn:nbn:de:bvb:703-epub-4027-2
Date Deposited: 19 Feb 2019 09:35
Last Modified: 19 Feb 2019 09:35
URI: https://epub.uni-bayreuth.de/id/eprint/4027

Downloads

Downloads per month over past year