低弗劳德数水跃的水跃长度计算方法
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摘要
低弗劳德数水跃具有消能率低、稳定差等特点,其水跃长度除了需考虑首部旋滚区外,还需要考虑后部波动区长度。基于12个适用于低弗劳德数水跃长度的计算公式,利用Hughes的模型试验结果对比各公式的差异性,分析获得产生差异的主要原因在于是否考虑跃后波动区长度和波动区长度判断标准。然后以Fr1为2.5～4.5作为控制边界,进行了7组水槽试验并提出波动区长度的判定方法。研究表明,朱荣林公式与水槽试验结果符合较好,可用于计算水跃长度;得出了考虑波动区后水跃长度与旋滚区长度之间的函数关系,为实际工程设计提供了指导。
Hydraulic jump with low Froude number has the characteristics of low energy dissipation rate and the poor stability.The length of hydraulic jump should consider the rolling zone and the fluctuation area.Twelve jump length formulas are collected and the results of these formulas are compared based on Hughes test.After analysis,the main reasons for the differences of the results are whether we consider the fluctuation zone or not and the different criteria for judging the length of fluctuation region.Taking the Fr1 in the range of 2.5 and 4.5 as control boundary,seven groups of flume tests are then carried out,and a method is put forward to determine the length of wave zone.The results show that Zhu Ronglin's formula is in good agreement with the experimental results,and it is recommended for the calculation of the hydraulic jump length.The relationship between the rolling area and the jumping zone is obtained.So,the research can provide guidance for the practical engineering design.
Hydraulic jump with low Froude number has the characteristics of low energy dissipation rate and the poor stability.The length of hydraulic jump should consider the rolling zone and the fluctuation area.Twelve jump length formulas are collected and the results of these formulas are compared based on Hughes test.After analysis,the main reasons for the differences of the results are whether we consider the fluctuation zone or not and the different criteria for judging the length of fluctuation region.Taking the Fr1 in the range of 2.5 and 4.5 as control boundary,seven groups of flume tests are then carried out,and a method is put forward to determine the length of wave zone.The results show that Zhu Ronglin's formula is in good agreement with the experimental results,and it is recommended for the calculation of the hydraulic jump length.The relationship between the rolling area and the jumping zone is obtained.So,the research can provide guidance for the practical engineering design.
引文
[1]刘沛清.关于水平矩形渠道中水跃长度的讨论[J].水利学报,1993(1):58-60,67.
[2]张迎春.自由临界水跃长度的探讨[J].中国农村水利水电,1997(10):38-41,48.
[3] Hughes W C,Flack E J.Hydraulic Jump Properties over a Rough Bed[J].Journal of Hydraulic Engineering,1984,110:1 755-1 771.
[4]张志昌,李若冰,傅铭焕,等.矩形明渠自由水跃长度的理论分析[J].水力发电学报,2013,32(6):108-114.
[5]傅铭焕,张志昌.密排加糙床面消力池自由水跃跃长计算[J].水利水运工程学报,2016(6):69-75.
[6]王勤香.泄水建筑物下游低弗劳德数水跃长度研究[J].人民长江,2014,45(17):63-65,93.
[7]张志昌,赵莹,傅铭焕.矩形平底明渠水跃长度公式的分析与应用[J].西北农林科技大学学报:自然科学版,2014,42(11):190-198.
[8]王冰洁,刘韩生.折坡扩散消力池水跃共轭水深计算方法及水跃长度、消能率分析[J].水电能源科学,2014,32(8):108-111.
[2]张迎春.自由临界水跃长度的探讨[J].中国农村水利水电,1997(10):38-41,48.
[3] Hughes W C,Flack E J.Hydraulic Jump Properties over a Rough Bed[J].Journal of Hydraulic Engineering,1984,110:1 755-1 771.
[4]张志昌,李若冰,傅铭焕,等.矩形明渠自由水跃长度的理论分析[J].水力发电学报,2013,32(6):108-114.
[5]傅铭焕,张志昌.密排加糙床面消力池自由水跃跃长计算[J].水利水运工程学报,2016(6):69-75.
[6]王勤香.泄水建筑物下游低弗劳德数水跃长度研究[J].人民长江,2014,45(17):63-65,93.
[7]张志昌,赵莹,傅铭焕.矩形平底明渠水跃长度公式的分析与应用[J].西北农林科技大学学报:自然科学版,2014,42(11):190-198.
[8]王冰洁,刘韩生.折坡扩散消力池水跃共轭水深计算方法及水跃长度、消能率分析[J].水电能源科学,2014,32(8):108-111.