Weissenberg effect
In fluid dynamics, the Weissenberg effect is a phenomenon that occurs when a spinning rod is inserted into a solution of elastic liquid. Instead of being thrown outward, the solution is drawn towards the rod and rises up around it.[1] This is a direct consequence of the normal stress that acts like a hoop stress around the rod. The effect is a common example of non-Newtonian fluid dynamics, which has been shown to occur for polystyrene.[2]
However, it is not always necessary to insert a rod to observe this effect. A rotating disk at the bottom of a viscoelastic non-Newtonian fluid can produce a similar phenomenon: the fluid rises at the center, whereas a Newtonian fluid forms a depression,[3] as seen when stirred with a magnetic stirrer.
The height of the fluid at the center increases with both the rotational speed of the disk and the elasticity of the fluid.[4]
The effect is named after Karl Weissenberg who published about it in 1947.[5]
References
[edit ]- ^ "Research".
- ^ "Article on the Weissenberg effect by Non-Newtonian Fluid Dynamics Group at the Massachusetts Institute of Technology".
- ^ "Abstract: Viscoelastic Flow in Microchannels" (PDF). APS Division of Fluid Dynamics Meeting Abstracts (DFD08) (Conference abstract). American Physical Society. 2008. Retrieved 2025年11月11日.
- ^ "Abstract: Viscoelastic Flow in Microchannels" (PDF). APS Division of Fluid Dynamics Meeting Abstracts (DFD08) (Conference abstract). American Physical Society. 2008. Retrieved 2025年11月11日.
- ^ Weissenberg, K. (1947年03月01日). "A Continuum Theory of Rhelogical Phenomena" . Nature. 159 (4035): 310–311. Bibcode:1947Natur.159..310W. doi:10.1038/159310a0. ISSN 1476-4687. PMID 20293529.
External links
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