窄缝急流冲击波与水舌扩散规律研究

Location of the Confluence of Rapid Shock Waves and Regularity of Water Tongue Diffusion of Slit-Type Energy Dissipator

采用模型试验手段,通过改变来流断面水流弗氏数Fr及窄缝收缩比β2个参数,重点研究了窄缝挑坎内急流冲击波交汇点位置及水流出坎后扩散规律。研究结果表明:β对冲击波交汇点位置影响较大,而来流Fr影响较小;β越大,冲击波交汇点越靠近挑坎出口;冲击波交汇后,挑坎内表面水体开始起挑,随着β的增大,水流出射角相应减小,β=0.2～0.25时,冲击波交汇点距挑坎出口距离占挑坎总长30%～40%,此时水舌扩散充分性及稳定性都较优。研究成果进一步丰富了对窄缝挑坎水力特性的认识,并为设计提供一定的理论依据。

By changing the inflow Froude number Fr and the contraction ratio fl of narrow slit in model we researched the confluence location of rapid shock waves and the diffusion regularity of flow out of experiments, the slit-buck- et. Results show that ： fl has larger influence on the confluence location of rapid shock waves than Fr does ; the lar- ger fl is, the closer the confluence location is to the flip bucket outlet. After the shock waves meet, the surface wa- ter in the bucket starts to shoot, and the outflow angle reduces correspondingly as/3 increases. When β = 0.2 - 0.25, the distance of confluence location from the outlet accounts for 30% -40% of the total length of the flip buck- et, in which case the water tongue diffusion is more sufficient and stable. The research results enriched the under- standing of hydraulic characteristics in slit-type bucket, and provide a theoretical basis for relative design.