After the pumps have been set to achieve the desired cross-shore distribution
of the depth-average longshore current at the lateral boundaries, an experiment
can begin by generating waves.
Considerable experience has been obtained using the procedures described in
this chapter. In regard to wave generation, GEDAP batch files were developed to
synthesize regular and irregular wave machine drive signals to maintain
consistency from one experiment to the next. Further information regarding the
individual GEDAP programs can be obtained using the on-line documentation.
The procedure developed to calculate the required discharge rates for the 20
vertical turbine pumps to recirculate the desired magnitude and cross-shore
distribution of the depth-average longshore current has proven to be accurate and
dependable. This procedure takes into account the complexities involved in
conducting sediment transport experiments with a moveable bed in which the
beach profile shape changes as the waves and currents interact with the moveable
bed. In addition, the method used to set the speed of the pumps using variable
frequency motor controllers has proven to be very accurate and requires minimal
time and human effort.
Wave Generation and Current Recirculation