Effect of Polymer Additives on Nozzle Stream Coherence: A Preliminary Study
Abstract
It is well known that certain water-soluble polymers will substantially reduce pipe-wall friction in turbulent flow situations. Pipe-line pressure-drop reductions of up to 75 (depending on Reynolds' number) have been obtained with polymer concentrations of only a few parts per million, and these results have been readily duplicated by many independent investigators. Civic fire departments have become interested in using the effect, and recently publicized has been a program by NYFD in collaboration with Union Carbide, producer of the highly effective friction-reducing polymer, poly(ethylene oxide), (tradename Polyox). Fire fighting applications could use the technique to reduce friction drop along hose lays so as to increase nozzle pressure for greater throw, increase flow through existing lays, reduce pumping power requirements, extend hose length without sacrificing flow rate, or reduce the hose diameter for a given application. Precisely how polymer friction reduction should be exploited would depend upon the specific fire fighting application; for instance, increased nozzle pressure for greater throw might be of prime interest in fighting high-rise fires, whereas extending hose length or reducing hose diameter might be of greater concern in fighting brush fires. Another way in which dissolved polymers might aid firefighting applications would be in improving stream coherence so as to concentrate the water delivery pattern, make the stream dispersion less sensitive to wind, and possibly to further increase stream throw. This study was directed towards obtaining controlled observations of the stream coherence effect. It was to be a limited investigation involving readily available equipment where relatively few parameters could be studied, and these only over a restricted range of conditions as dictated by the test apparatus. A more thorough investigation would depend upon results of this preliminary study.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1971
- Accession Number
- AD1068484
Entities
People
- J. H. Green