Revised method for calculating stratification ratios for hetrogeneous flows
2008 (English)In: Conference Proceedings, 14th International Conference on Transport and Sedimentation of Solid Particles: 23-25 June 2008, Saint Petersburg, Russia, 2008, 334-340 p.Conference paper (Refereed)
With its well-instrumented pipe loops of various sizes, the GIW Hydraulic Laboratory has, over the years, developed a large corpus of slurry-transport data. Numerous technical papers have been produced, and also a textbook, now in its third edition. A paper from 1982, together with the first and second editions of the text, presented methods of calculating stratification ratios for pipeline flows of heterogeneous slurries. This stratification ratio (R), which is needed in calculating pressure drops for particulate pipeline flows, is the fraction of total solids that contributes to mechanical friction by rubbing against the bottom of the pipe. The remaining solids are carried by the fluid phase. A combination of experimental work and analysis published in the last few years has shown the importance of the fluid force developed near the pipe wall. The influence of this force is now applied to the stratification ratio. The basic parameter is seen to be the ratio of the near-wall lift force on a particle to its submerged weight. This ratio depends primarily on a dimensionless quantity denoted Θ, and is also influenced by the lift coefficient of the particle, which, in turn, introduces a minor dependence on a particle Reynolds number Re*. It was noted that the quantity Θ is itself composed of a Froude Number for the flow (which can be related to the deposition limit) and the diameter ratio d/D. An analysis of experimental data has given a new expression for R in terms of Θ and Re*.
Place, publisher, year, edition, pages
2008. 334-340 p.
Research subject Water Resources Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-35500Local ID: a0d4fb10-d10f-11dd-9979-000ea68e967bOAI: oai:DiVA.org:ltu-35500DiVA: diva2:1008753
International Conference on Transport & Sedimentation of Solid Particles : 23/06/2008 - 27/06/2008
Godkänd; 2008; 20081223 (ysko)2016-09-302016-09-30Bibliographically approved