Laboratory study of crossbeam structural design in control of asymmetric S- type jump of sudden expansion sections

This paper presents an experimental study on a proposed dissipation structure consisting of a series of cross beams tested in different geometric configurations and hydraulic conditions. First, the effectiveness of this system was analyzed in terms of uniformity of flow and bed velocity. While observing the dissipating mechanisms, in the next step, the system performance under variable tailwater conditions by describing the three-dimensional flow patterns observed in the downstream channel with a gradual decrease in downstream level to 70%, 80%, and 90% of tailwater depth in the conditions the reference experiments were tested. Measurement of three-dimensional velocities to determine the parameters of flow uniformity, momentum, and energy coefficients, analysis of three-dimensional velocity distributions, turbulent kinetic energy, supplementary studies on the development of isothermal line concentration and drop energy losses of reference experiments, and optimal case compositions were examined. The results showed that in addition to the similar qualitative trends of β and α, the flexibility of the dissipation structure has high efficiency in the effective homogenization of the flow in the abrupt expansion channel, even in the downstream water level conditions.