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CHAPTER 2: EXPERIMENTAL EQUIPMENT AND METHODS
SUMMARY
An experimental flume was designed and constructed to be
adaptable and of sufficient size to allow the study of reasonably
scaled sandwave bedforms. The facility was 6.7m in length and
0.45m square cross-section, with perspex side walls and base.
The inlet flow was calmed using Raschig rings which were adjusted
until even flow across the width of the flume was achieved. A
series of three perspex triangular-cross-section bedforms were
fitted in the working section to model sandwaves.
Experimental techniques concerning fluid and particle
visualisation, particle trajectory analysis and concentration
profiling, which were applied to particle motions from the crest,
lee and stoss slopes, are also detailed. These techniques were
developed in existing equipment and during a summer visit to HR
Wallingford, where extensive practical trials were carried out
(as detailed in appendix 8).
Suggestions for future modifications to the rig include fitting
a stainless steel pump to prevent water discolouration and
provision of permanent flow and depth metering equipment.
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