摘要
输水管道或泄洪洞常见的内消能方式为孔板和洞塞,结合明渠水流中的消能工形式提出了齿墩状内消能工,并通过物理模型试验对不同面积收缩比的齿墩状内消能工进行了研究,分析了它们的过流能力、消能率、压强沿程变化及脉动压强特性.结果表明:齿墩状内消能工的过流能力主要是由消能工的体型及尺寸决定的,其面积收缩比越大,消能率越低,过流能力就越强;齿墩状内消能工的时均压强在收缩段骤降,在其后部逐渐上升,而后恢复至稳定,其恢复长度基本相同;齿墩状内消能工的脉动压强最大点均出现在收缩段后1倍圆管直径范围内,随后迅速减小,逐渐趋于平稳;面积收缩比为0.471 2的齿墩状消能工的脉动强度最小,因而其抗空化性能优于其他情况,且脉动压强最大点的压强概率密度分布接近正态分布.
Combining the common inner dissipation way of the orifice and the plug in water pipe or spillway with the dissipation way in free flow,the inner energy dissipater of tooth block was proposed,and the tooth block with different area contraction ratio by physical modeling experiment was studied to analyze its conveyance capacity,dissipation ratio,pressure changes along the tube and the characteristics of fluctuating pressure. The results show that the conveyance capacity of tooth block dissipater is mainly determined by the energy dissipater's shape and size. The conveyance capacity is proportional to the area contraction ratio,while the energy dissipation ratio is opposite. The time-averaged pressure of schemes drops suddenly in contraction section,then gradually rises and returns to stability,and their recovering length is almost the same. The maximum point of pressure fluctuation appears at 1 time tunnel diameter away from outlet of the tooth block,and decreases rapidly along the tube,and then becomes stability after 4 times tunnel diameter. The tooth block with area contraction ratio of 0. 471 2 has a better capacity of resisting cavitation than others as its pulsating strength is small,and its distribution of the probability density is approximate to Gauss distribution.
出处
《排灌机械工程学报》
EI
北大核心
2014年第2期136-139,161,共5页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51109155)
山西省自然科学基金资助项目(2013011037-4)
关键词
齿墩状内消能工
时均压强
脉动压强
过流能力
消能
inner energy dissipaters of tooth block
time-averaged pressure
fluctuating pressure
conveyance capacity
energy dissipation
