The effect of expansion ratio for creeping expansion flows of UCM fluids

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Poole, RJ (Author) Other; Pinho, FT (Author) FEUP; Alves, MA (Author) FEUP; Oliveira, PJ (Author) Other

Journal

Title: Journal of Non-Newtonian Fluid Mechanics

Vol. 163 No. 1-3

Pages: 35-44

ISSN: 0377-0257

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 17 Citations

ISI Web of Science

Scopus - 19 Citations

COMPENDEX

INSPEC

Scientific classification

FOS: Engineering and technology > Mechanical engineering

CORDIS: Technological sciences > Engineering > Mechanical engineering ; Technological sciences > Engineering > Chemical engineering

Other information

Authenticus ID: P-003-ERV

DOI: 10.1016/j.jnnfm.2009.06.004

Abstract (EN): A systematic numerical investigation on creeping flows in planar sudden expansions of viscoelastic fluids obeying the upper-convected Maxwell model is carried out to assess the combined effects of viscoelasticity, through the Deborah number, and expansion ratio (ER), which was varied between 1.25 and 32. At large expansion ratios (ER >= 4) the flow becomes dominated by the downstream duct size and appropriately normalized quantities tend to be independent of ER. The recirculation size and strength become decreasing functions of De, whereas the Couette correction (the normalized entry pressure drop due to the presence of the expansion) increases. At small ER (ER <= 3), however, no simple scaling laws are found and there is a complex interaction between De and ER leading to non-monotonic variations, with an initial decrease in the recirculation length at low Deborah numbers, followed by an enhancement as De increases.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10