TURBULENT PIPE-FLOW CHARACTERISTICS OF LOW-MOLECULAR-WEIGHT POLYMER-SOLUTIONS

• Type: Article in International Scientific Journal
• Date: 1994

Authors

PEREIRA, AS (Author) Other; F. T. Pinho (Author) FEUP

Journal

Title: Journal of Non-Newtonian Fluid Mechanics

Vol. 55

Pages: 321-344

ISSN: 0377-0257

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 20 Citations

Scopus - 30 Citations

Other information

Authenticus ID: P-001-J8R

Abstract (EN): Detailed mean velocity, normal Reynolds stress and pressure drop measurements were carried out with 0.4 to 0.6% by weight aqueous solutions of Tylose, a methylhydroxil cellulose (molecular weight 6000) from Hoechst after a selection process from a set of low molecular weight fluids. The viscosity measurements of the Tylose solutions showed shear-thinning behaviour, and the oscillatory and creep tests measured elastic components of the stress of the order of the minimal detectable values by the rheometer. These low molecular weight polymer solutions delayed transition from the laminar to the turbulent regime and showed drag reductions of half that reported to occur with other low elasticity shear-thinning high molecular aqueous polymer solutions. Near the wall the axial turbulent stress was higher than with water, whereas the two transverse components of turbulence were reduced. This near-wall behaviour is typical of drag reducing fluids based on high molecular weight polymers, but in the core of the pipe the three components of turbulence were higher than for the water flows, especially in the radial and tangential directions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 24