Experimental Study on Backwater in Cavity of Aerator on Chute with Mild Slope

Abstract:

Aerator is often used in the spillways or tunnels to protect these discharge release works from cavitation damage. But for the flow chutes with mild bottom slope, the backwater may occur easily in the aerators cavity. There are a lot of factors to influence the backwater in the cavity. Based on the model experiments and analysis, the backwater in the bottom aerators cavity on the chutes with mild bottom slope and some influence factor to the backwater are investigated. The research presented in this paper provides some laws of how backwater exists in the aerators cavity and how to reduce backwater in the cavity. Results show, in the case of other conditions remain unchanged, flow discharge is inversely proportion to the depth of backwater, and the takeoff angle of aerator affects the depth of backwater larger than the slope of chute; the greater the flow discharge is, the lower the depth of backwater. And the depth of backwater increases with aerator height. More attention should be paid to the backwater in the cavity for the chute with small bottom slope.

• Periodical: Applied Mechanics and Materials (Volumes 405-408)
• Pages: 495-498
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.405-408.495
• Online since: September 2013
• Authors: Liang Qiao, Yi Min Xu, Yan Rong, Guan Bo Ma, Chun Ying Shen
• Keywords: Aerator, Depth of Backwater, Hydraulics, Jet Flow Impact Angle, Mild Slope

References

[1] MICHAEL P., HAGER W. H. Chute aerators II: Hydraulic design [J]. Journal of Hydraulic Engineering, ASCE, 2010, 136(6): 360-367.

DOI: 10.1061/(asce)hy.1943-7900.0000201

[2] MICHAEL P., HAGER W. H. Chute aerators I: Air transport characteristics [J]. Journal of Hydraulic Engineering, ASCE, 2010, 136(6): 352-359.

DOI: 10.1061/(asce)hy.1943-7900.0000189

[3] RUAN Shi-ping, WU Jian-hua, WU Wei-wei. Hydraulic research of aerators on tunnel spillways[J]. Journal of Hydrodynamics, Ser. B, 2007, 19(3): 330-334.

DOI: 10.1016/s1001-6058(07)60066-3

[4] SU Pei-lan, LIAO Hua-sheng, QIU Yue, LI Chen-juan. Experimental study on a new type of aerator in spillway with low Froude Number and mild slope flow [J]. Journal of Hydrodynamics, 2009, 21(3): 415-422.

DOI: 10.1016/s1001-6058(08)60165-1

[5] WU Jian-hua, RUAN Shi-ping. Cavity length below chute aerators [J]. Science in Chnia, Ser. E: Technology Science, 2008, 51(2); 170-178.

DOI: 10.1007/s11431-008-0009-9

[6] MICHAEL P. Chute aerators: Steep deflectors and cavity sub-pressure [J]. Journal of Hydraulic Engineering, ASCE, 2011, 137(10): 1208-1215.

DOI: 10.1061/(asce)hy.1943-7900.0000436

[7] KÖKPINAR M. A., GÖĞŰŞ M. High-speed jet flow chute aerators [J]. Canadian Journal of Civil Engineering, 2002, 29(6): 885-898.

[8] ZHANG Jian-min, CHEN Jian-gang and XU Wei-lin etal. Three-dimensional numerical simulat6ion of aerated flows downstream sudden fall aerator expansion-in a tunnel [J]. Journal of Hydrodynamics, 2011, 23(1): 415-422.

DOI: 10.1016/s1001-6058(10)60090-x

[9] MA Fei, WU Jian-hua. Flow regimes below aerators for discharge tunnels[J]. Journal of Hydrodynamics, Ser. B, 2012, 24(3): 378-382.

DOI: 10.1016/s1001-6058(11)60258-8

[10] Yimin Xu, Wei Wang, Hongxuan Yong, Wei Zhao. Investigation on the cavity backwater of the jet flow from the chute aerators [J]. Procedia Engineering 31 (2012) 51-56.

DOI: 10.1016/j.proeng.2012.01.989