Squeezing flow of a double layered array of two newtonian liquids

✍ Scribed by Seung Ju Lee; O.H. Campanella; M. Peleg

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 628 KB
• Volume: 44
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(89)85107-3

✦ Synopsis

The theoretical behavior of a double layered array of two Newtonian liquids in ideal, isothermal, lubricated (frictionless) and non-lubricated, squeezing flows between parallel plates is described in terms of dimensionless force-time or thickness-time relationships. In lubricated flow at a constant displacement rate, when the viscosity ratio was higher than ten, a distinct transient region, reminiscent of viscoelastic deformation was clearly evident in the force-time curves. Under constant load, in contrast, the array's behavior was always similar to that of a single layer with an intermediate viscosity. In non-lubricated flow the force levels were about tenfold or more higher than in lubricated flows under the same conditions. The relative position of the force-time curves in flows at a constant displacement rate or thickness-time curves constant load, is not only determined by the layer's thickness and viscosity ratios, as is the case in lubricated flow, but also by the relation between frictional and viscous effects. Thus, for example, curves of certain double layered arrays can be higher than those of a single layer containing the liquid with the higher viscosity.