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UNSTEADY DISPERSION IN RANDOM INTERMITTENT FLOW
Citation:
Cutter, M. R., S. G. Bachberger, AND M Meckes*. UNSTEADY DISPERSION IN RANDOM INTERMITTENT FLOW. Presented at World Water & Environmental Resources Congress 2004, Salt Lake City, UT, June 27 - July 01, 2004.
Impact/Purpose:
To inform the public.
Description:
The longitudinal dispersion coefficient of a conservative tracer was calculated from flow tests in a dead-end pipe loop system. Flow conditions for these tests ranged from laminar to transitional flow, and from steady to intermittent and random. Two static mixers linked in series were used to mix the tracer and homogenize the concentration across the cross-section of pipe. The concentration of the tracer was measured downstream of the injection and mixers via conductivity probes at two points in the cross-section. The calculated dispersion coefficients are plotted versus Reynolds number for each of the probe locations, as well as for an average dispersion value. Under steady-flow conditions, the dispersion coefficient was shown to increase with flow rate. Similarly, dispersion coefficients were shown to increase under intermittent and random flow conditions. Application of these results in a water distribution network simulator can be used to improve water quality predictions in dead-end portions of the network.