Air-core characteristics in a swirling tunnel flow

doi:10.1007/s42241-022-0047-y

	Air-core characteristics in a swirling tunnel flow
	Nan, Jun-hu 1,3; Gao, Huan 1; Wang, Chao-qun 1; Ma, Kang-ning 1; Yang, James 2; Wei, Jia-fang 1; Li, Guo-dong 3
刊名	Journal of Hydrodynamics
	2022
关键词	Air entrainment Hydroelectric power Swirling flow Air-carrying capacity Air-core Condition Core features Cost effective Energy Horizontal tunnel Hydropower system Scale effects Tunnel flow
ISSN号	1001-6058
DOI	10.1007/s42241-022-0047-y
英文摘要	A cost-effective technique to dissipate the energy in hydropower systems is the formation of a swirling flow within a tunnel. In such flows, an air core with a significant cross section usually occurs. To reveal the air-core features in the horizontal tunnel of a high-head shaft spillway, laboratory tests, numerical modeling, and prototype observations are performed, to examine issues such as the formation of the air core, the interjacent air motion, the air-carrying capacity, and the scale effects. It is shown that the shape of the air core varies greatly in the axial and radial directions along the tunnel and that the center of the core deviates from the axis of the tunnel. The motion of the air within the core is caused by the combined action of the water entrainment on the inner surface of the swirling flow and the axial pressure difference in the air core. The aeration process can be divided into five processes with respect to the changes of the gate openings. A theoretical expression is established for the air-carrying capacity of the swirling flow. The vacuum degree is the similarity condition of the air-carrying capacity of the swirling flow between the model and prototype tests based on the Froude law of the similitude, and this similarity condition is verified by both the model and prototype results. This work provides a reference for the application of the swirling flows in horizontal hydropower tunnels. © 2022, China Ship Scientific Research Center.
WOS研究方向	Mechanics
语种	英语
出版者	Springer
WOS记录号	WOS:000842366600001
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/159775]
专题	能源与动力工程学院
作者单位	1.College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; 2.Department of Civil and Architectural Engineering, Royal Institute of Technology (KTH), Stockholm, Sweden 3.State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an; 710048, China;
推荐引用方式 GB/T 7714	Nan, Jun-hu,Gao, Huan,Wang, Chao-qun,et al. Air-core characteristics in a swirling tunnel flow[J]. Journal of Hydrodynamics,2022.
APA	Nan, Jun-hu.,Gao, Huan.,Wang, Chao-qun.,Ma, Kang-ning.,Yang, James.,...&Li, Guo-dong.(2022).Air-core characteristics in a swirling tunnel flow.Journal of Hydrodynamics.
MLA	Nan, Jun-hu,et al."Air-core characteristics in a swirling tunnel flow".Journal of Hydrodynamics (2022).