It is further assumed that the width of the channel, 92.5 cm, is
sufficient that edge effects are largely eliminated at the centre.
This width is similar to large-scale test rigs used by other
investigators [31,32,38], and most small-scale investigations had
similar height-to-width ratios. Therefore, the conditions measured at the centre line of the test rig are taken to be representative
of the conditions in an infinitely wide channel. However, this
assumption may be tested in future experiments.