渐扩散水跃跃长的研究

首先通过对作用于渐扩散水跃的压力分析,阐述了渐扩散水跃跃长总比非扩散水跃跃长短的原理。在此理论基础上,考虑边墙扩散角的影响,建立了渐扩散水跃表面质点运动方程,并结合动量方程和连续方程,推导出渐扩散水跃跃长的半理论、半经验公式。同时,引入非扩散水跃跃长经验公式,使渐扩散水跃跃长公式大大简化。其次,对该理论的局限性进行了分析,得到了该公式的适用范围。在该范围内,该公式能较好地吻合实验结果,从而该理论得以证实。最后对各家渐扩散水跃跃长经验公式进行分析归类,并推荐工程适用公式,以便工程运用。

Length of hydraulic jump in gradually broadened channel

The length of hydraulic jump in the gradually broadened channels is studied in this paper. Firstly, the hydraulic pressure acting on the hydraulic jump in the gradually broadened channel is analyzed, and why the length of hydraulic jump is always shorter in the gradually broadened channel than in the non-broadened channel expounded. Considering the influence of the divergence angles on the jump, an approximate expression for the water surface profile of the jump in the gradually broadened channel is written based on this analysis. From the expression, the momentum equation and the continuous equation of the flow, the semi-empirical formula for calculating the length of the jump in the gradually broadened channel is derived. At the same time, the simplified solution to the semi-empirical formula is proposed by employing an empirical formula for calculating the length of hydraulic jump in the non-broadened channel. Secondly, the limitations of the semi-empirical formula are pointed out. Based on the limitations, lidity of the semi-empirical formula is the length of hydraulic jump in the the stilling basin. We hope that the the applicable ranges of the semi-empirical formula are obtained. In the ranges the vaverified with the experimental data. Lastly, the most empirical formulae for calculating gradually broadened channel are classified and recommendation is useful to the designers. some are recommended for the designers of the stilling basin. We hope that the recommendation is useful to the designers.