Return to search

Effect of drag-reducing additives on pipe flow : Visualization with laser holographic interferometry

The effect of turbulence damping polymer additive on the fluid flow structure near the wall region of a circular pipe was made visible using real-time laser holographic interferometry. The interference fringes were recorded by high-speed motion photography.
The gross flow behaviour of dilute solutions of Polyox WSR 301 in distilled water was studied in a 2.63 cm pipe. It was observed that
(i) The onset of drag reduction occurred at a critical value of wall shear stress and Reynolds number.
(ii) The fluid property parameter, δ, which governs the drag reduction capacity of the solution, had a power-law dependence on polymer concentration given by [23]
[ Formula omitted ]
Motion pictures of real-time holographic fringe displays for pure solvent and polymer solution were appraised qualitatively. Under similar flow conditions turbulent eddies in drag-reducing flow were observed
(i) to show less small scale structure than those in the pure solvent, and
(ii) to burst from the wall region into the bulk flow with a lower frequency. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Identiferoai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/33284
Date January 1971
CreatorsAchia, B. Umesh
PublisherUniversity of British Columbia
Source SetsUniversity of British Columbia
LanguageEnglish
Detected LanguageEnglish
TypeText, Thesis/Dissertation
RightsFor non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

Page generated in 0.002 seconds