Withdrawal of power law fluid films

✍ Scribed by P. Groenveld

• Publisher: Elsevier Science
• Year: 1970
• Tongue: English
• Weight: 532 KB
• Volume: 25
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(70)85080-1

✦ Synopsis

The thickness of a layer of a power law fluid on a sheet, which is withdrawn from a bath, is determined for the three regimes of withdrawal conditions. The flux in viscous withdrawal is, like for a newtonian liquid, lower than the maximum possible flux on a sheet moving upwards with a certain velocity. The difference, which is only 17 per cent for a newtonian liquid, increases considerably with increasing pseudoplasticity of the fluid. This phenomena gives a better explanation for the low fluxes measured by Gutfinger and reported in this work than the theories proposed by Tallmadge, Gutfinger and Hildebrand, which are all based on the maximum flux theory. ' v (KU") ' v (rp) GrkdzZ:viscosity, Ns/m2 Reynolds number, pv2+hnlK, pvhlv 8 yield value, N/m2 dimensionless thickness, h(&yil,h($)1'2 ' density' kg'?3 CT surface tension, N/m