The Weissenberg Effect: An Introduction

In 1947, Karl Weissenberg published a paper discussing the ability of some fluids to climb a spinning rod. This phenomena, commonly referred to as the "Weissenberg Effect," has an elusive reasoning that requires at least a basic understanding of fluid characteristics and behaviors. This video, created for an extra credit assignment for University of Tennessee Chemical Engineering student Christopher Neal's Fluid Flow and Heat Transfer class, discusses those basic fluid behaviors and seeks to describe the way that pseudoplastics conglomerate around and climb a spinning rod exposed to rotational shearing.

[@terryivinho3228]

I saw this video years ago. It's nice to have finally found it again. Very interesting.

[@ThoseOneAirsofters]

Great video! Explained the effect way better than my professor did.

[@ubhelbr]

soviet people used this effect during prohibition times to extract unwanted chemicals from an ethanol-containing glue, as was even immortalized in a song

[@zemyla]

If pseudoplastics exhibit the Weissenberg effect, do dilatant fluids show the opposite?

[@grantmayberry7358]

Well, now I have another physical phenomena to obsess over for a month.

[@sergeyvagner9236]

Wrong explanation. This effect does not have to do with pseudoplastisity. It's about normal stress difference.

[@christopherneal4804]

Hi Sergey, you are absolutely right. Rod climbing is due to normal stresses produced during shearing. I incorrectly stated in the video that it's due to the pseudo plasticity. In reality, MOST materials that have normal stress effects are pseudo plastics (and perhaps all, I'm not sure), but it is more accurate to say it is due to the normal stresses rather than pseudo plasticity alone. Thanks for your comment!

[@Sebastian-qf1gt]

Mucho texto.jpg

[@RTL_CSQ]

MOON GOO
DIE SWELL

[@samarawilliams1987]

its actually Newtonian fluids that have that effect . I'm doing a lab report and a lot of that is wrong

[@christopherneal4804]

Hi Samara. I'm not sure where you heard this but thats not exactly true. Newtonian fluids don't exhibit shear thinning or thickening as the shear rate increases. Notice the diagram in the slides that shows a constant viscosity for Newtonian fluids. Without a change in viscosity, the Weissenberg effect cannot occur.

[@adamfarris1458]

@@christopherneal4804 You beat me to the reply!

[@glashaedits]

a lot of that lab report will be wrong