Experiments to dambreak wave: Sloping channel

Abstract

Dambreak flows in a smooth, rectangular channel are considered. In all experiments, the abrupt rupture on an absolutely dry tailwater channel was modelled. The effect of bottom slope up to 50% is analyzed, and the results are compared with those pertaining for the horizontal channel. The positive and negative wave fronts are determined based on the characteristic equations. Also, the drying front is computed and the effect of viscosity is analyzed. The experiments are in agreement with the observations collected with a specially designed Video system. The positive wave front is found to tend towards a pseudo-uniform flow for large locations downstream of the dam section. The characteristics of the dambreak waves are then described, including the maximum wave height, and a generalized wave profile. The decay of maximum wave height is related to a combined parameter that includes the position, the bottom slope and the initial water depth. Further, the velocities in the wave body are determined and the velocity distribution is discussed. The discharge as the product of depth times velocity is demonstrated to be nearly independent of the bottom slope. With these results, a rather complete description of the dambreak wave can be furnished.