According to the definition of frictional head loss, the theoretical relations of frictional head loss with coefficient of bed resistance, conjugate depth ratio of hydraulic jump, ratio of width to height of initial section, and initial depth are deduced. The theoretical calculation equations of frictional head loss coefficient and the local head loss coefficient of free hydraulic jump in rectangular open channel are given, and the simple fitting formulas of frictional, local, and total head loss coefficients are put forward. It is shown that frictional head loss grows with the rise of the initial depth of hydraulic jump and the coefficient of bed resistance; but declines with the increase of the conjugate depth ratio and the ratio of width to height of initial section. Local head loss coefficient augments with the increasing of the Froude number of initial section. The proportion of local head loss in the total head loss becomes larger with the increase of Froude number. When Froude number is 3, the proportion of local head loss is 90%, and when Froude number is 6, the proportion of local head loss is over 95%. The research results could improve and enrich the theoretical system of hydraulic jump.
Key words
rectangular open channel /
stilling pool /
hydraulic jump /
frictional head loss /
local head loss /
total head loss
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References
[1] 吴持恭.水力学(上册)[M].北京:高等教育出版社,2003:284-301.
[2] 清华大学水力学教研组.水力学(下册)[M].北京:高等教育出版社,1982:198-203.
[3] 张志昌,赵 莹.矩形明渠水跃段沿程和局部水头损失的计算[J].水力发电学报,2015,34(11):88-94.
[4] 倪汉根,刘亚坤.击波 水跃 跌水 消能[M].大连:大连理工大学出版社,2008:134-192.
[5] EAD S A, RAJARATNAM N. Hydraulic Jumps on Corrugated Beds[J]. Journal of hydraulic engineering, 2002, 128(7): 656-663.
[6] ABBASPOUR A, HOSSEINZADEH DALIR A, FARSADIZADEH D, et al. Effect of Sinusoidal Corrugated Bed on Hydraulic Jump Characteristics[J]. Journal of Hydro-environment Research, 2009, 3(2):109-117.
[7] 张志昌,傅铭焕,李若冰.波状床面消力池共轭水深和水跃长度的计算[J].水力发电学报,2014,33(5):120-127.
[8] 张志昌,傅铭焕,赵 莹,等. 波浪形底板消力池自由水跃特性的探讨[J].应用力学学报,2013,30(6):870-875.
[9] 张志昌,傅铭焕,李若冰,等.波状床面消力池的流速分布和壁面阻力系数[J].长江科学院院报,2014,31(8):45-49,81.
[10] 张志昌,傅铭焕,赵 莹,等.人工粗糙壁面的水跃特性研究[J].应用力学学报,2014,31(2):270-274.
[11] 宁利中,宁碧波,田伟利,等.矩形扩散水跃方程的近似解[J].西安建筑科技大学学报(自然科学版),2013,45(6):875-879.
[12] 张志昌.水力学(下册)[M].北京:中国水利水电出版社, 2011:75,120-125.
[13] 张志恒.矩形扩散水跃的水力计算[J].陕西水利,1973(1):10-26.
[14] RAJARATNAM N. The Hydraulic Jump as a Wall Jet[J]. Journal of the Hydraulics Division, 1965, 91(5): 107-132.
[15] FRANCESCO G C, VITO F, VINCENZO P. Hydraulic Jumps on Rough Beds[J]. Journal of Hydraulic Engineering, 2007, 133(9): 989-999.
[16] HUGHES W C, FLACK J E. Hydraulic Jump Properties over a Rough Bed[J]. Journal of Hydraulic Engineering, 1984,110(12):1755-1771.
[17] 张志昌 张巧玲.明渠恒定急变流和渐变流水力特性研究[M].北京:科学出版社,2016:13-16.
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