A two-dimensional model for jet splashing rainfall intensity distribution in dam discharge based on laboratory experiments.

Flood discharge atomization is a phenomenon of water droplets and mist diffusion caused by dam discharge, which brings heavy rainfall around the dam. The unnatural rainfall is harmful to the safe operation of hydropower stations and the stability of slopes. Jet splashing is the most important factor in the formation of flood discharge atomization. The splashing rainfall intensity and diffusion region are highly dependent on the jet impingement conditions. In this study, a two-dimensional splashing model is derived that describes the splashing rainfall distribution when a jet impinges on a plunge pool surface in terms of the jet impingement conditions. Given the close relationship between the splashing rainfall intensity distribution and the motion trajectories of droplets, it is hypothesized that certain droplet trajectories can accurately represent the distribution of rainfall intensity. The characteristic ejection angle of splashing droplets and the splashing diffusion coefficient are introduced to estimate the characteristic trajectories of droplets. Experimental data from laboratory tests are used to estimate the parameters of the splashing model. The current predictions are compared with the data from laboratory tests and prototype observations. The results suggest that the model accurately predicts the relative rainfall intensity at the upper region of the predicted curves, which corresponds to approximately 1/10 of the total height of the ideal parabola. [ABSTRACT FROM AUTHOR]