Experiments on the Reverse Squeezing Flow of Dilute Polymer Solutions : 2nd Report, Water-Separan Solutions

• Published in: Transactions of the Japan Society of Mechanical Engineers Series B Vol. 55; no. 520; pp. 3691 - 3696
• Main Authors: NARUMI, Takatsune, HOSOKAWA, Yoshihiro, HASEGAWA, Tomiichi, KONNO, Masaaki
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 25.12.1989
• Subjects: Squeezing Flow
• ISSN: 0387-5016; 1884-8346
• DOI: 10.1299/kikaib.55.3691

Experiments have been conducted with dilute water-Separan solutions on the reverse squeezing flow between a flat plate and a spherical surface of a large radius of curvature. The separating motion is started from a stationary and contacting state by applying constant forces. The separating rate in the polymer solutions is compared with that predicted by power law fluids. At the beginning of the motion, the separating rates in the Separan solutions are smaller than those in the inelastic liquids, as was shown in the 1st report for PEO solutions. These results cannot be explained by ordinary continuum mechanics because of the very small clearance between two surfaces ion the center region where the molecular size is close to the clearance size. When the separation is increased in magnitude, a considerable difference is shown between the results of Separan and PEO solutions despite similar viscoelastic properties in steady flows. Namely, the separating rates in the PEO solutions are close to those in the inelastic liquid, while smaller rates are maintained in the case of Separan solutions. It is considered that these results are due to the difference between the unsteady viscoelastic properties, stress overshoot, for example, of two different polymer solutions.