Longitudinal dispersion of salt in the Volkerak estuary

Determination of longitudinal dispersion coefficients in open channel flow

10.3133/25218 ◽

1966 ◽

Keyword(s):

Channel Flow ◽

Open Channel ◽

Open Channel Flow ◽

Longitudinal Dispersion ◽

Dispersion Coefficients

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Longitudinal dispersion of radioactive substances in Federal waterways

Kerntechnik ◽

10.3139/124.100343 ◽

2007 ◽

Vol 72 (4) ◽

pp. 205-213 ◽

Cited By ~ 1

Author(s):

W. J. Krause ◽

W. Speer ◽

T. Lüllwitz ◽

M. Cremer ◽

W. Tolksdorf

Keyword(s):

Longitudinal Dispersion ◽

Radioactive Substances

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The effects of surcharged manholes on the travel time and dispersion of solutes in sewer systems

Water Science & Technology ◽

10.2166/wst.1995.0199 ◽

1995 ◽

Vol 31 (7) ◽

pp. 51-59 ◽

Cited By ~ 3

Author(s):

Ian Guymer ◽

Rob O'Brien

Keyword(s):

Travel Time ◽

Moment Method ◽

In Situ Measurements ◽

Time Change ◽

Longitudinal Dispersion ◽

Laboratory System ◽

Environmental Load ◽

Hydraulic Characteristics ◽

Sewer Systems

Previously, the design of sewer systems has been limited to studies of their hydraulic characteristics, in particular the ability of the system to convey the maximum discharge. Greater environmental awareness has necessitated that new designs, and some existing schemes, are assessed to determine the environmental load which the scheme will deliver to any downstream component. This paper describes a laboratory programme which has been designed to elucidate the effects of manholes on the longitudinal dispersion of solutes. A laboratory system is described, which allows in situ measurements to be taken of the concentration of a fluorescent solute tracer, both up- and down-stream of a surcharged manhole junction. Results are presented from a preliminary series of studies undertaken for a single manhole geometry over a range of discharges, with varying levels of surcharge. Results are presented showing the variation of travel time, change in second moment of the distribution and of a dispersion factor with surcharge, assuming a Taylor approach and determining the dispersion factor using a ‘change in moment’ method. The effect of the stored volume within the manhole is clearly evident. The limitations and the applicability of this approach are discussed.

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An investigation of fine sediment mixing within free-flowing and surcharged manholes

Water Science & Technology ◽

10.2166/wst.1998.0052 ◽

1998 ◽

Vol 37 (1) ◽

pp. 215-222

Author(s):

I. Guymer ◽

R. O'Brien ◽

O. Mark ◽

P. Dennis

Keyword(s):

Dead Zone ◽

Laser Induced Fluorescence ◽

Fine Sediment ◽

Longitudinal Dispersion ◽

Qualitative Description ◽

Suspended Material ◽

Mixing Processes ◽

Future Developments ◽

Mixing Effects ◽

Sediment Mixing

Previous studies of the effects of manholes on longitudinal dispersion has concentrated on the spreading of solutes. This papers presents new data describing the influence of a surcharged and free-flowing manhole structure on the longitudinal dispersion of a fine suspended material. The effects of benching within the manhole structure are also illustrated. Laser Induced Fluorescence (LIF) techniques have been used to provide a qualitative description of the mixing processes present within a surcharged manhole. Nephelometric results have provided estimates of the parameters required to simulate the mixing effects using either increase in variance or aggregated dead zone techniques. A preliminary attempt at describing these observations using available software is discussed and recommendations for future developments are made.

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