Computation of spatial submerged hydraulic jump with different abrupt expansion ratios
ZHENG Tie-Gang, DAI Hui-Chao, DING Quan-Lin
(1.Department of Hydraulics,China Institute of Water Resources and Hydropower Research, Beijing 100038, China; 2.State Key Laboratory of HydrologyWater Resources and Hydraulic Engineering, Hohai University,Nanjing, Jiangsu 210098, China; 3.College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu 210098, China)
Since the abrupt expansion can enlarge turbulence intensity level in a local range of water flow, it can be utilized as kind of important energy dissipaters. In order to study effects of abrupt expansion ratio on hydraulic characteristics of down stream flow, spatial submerged hydraulic jumps with the abrupt expansion ratios of 1.000, 0.833, 0.667, 0.500, 0.333 are simulated numerically based on a nonuniform structured mesh, the RNG k-ε turbulence model and the pressure and velocity coupling algorithmPISO. It was found that the change of abrupt expansion ratio has obvious influence on down stream velocity, turbulence kinetic energy and energy dissipation rate. The smaller the ratio, the more obvious the change in velocity, the faster the primary flow diffuses, and the more clearly the flow pattern transition develops. With decreasing expansion ratio, the smaller the turbulent stresses, the larger the energy dissipation rate. Compared with a typical hydraulic jump, the spatial submerged hydraulic jump possesses greatly improved energy dissipation rate. However, once the ratio is less than 0.5, the dissipation rate on longer is improved obviously yet.
ZHENG Tie-Gang,DAI Hui-Chao,DING Quan-Lin. Computation of spatial submerged hydraulic jump with different abrupt expansion ratios[J]. Journal of Drainage and Irrigation Machinery Engin, 2012, 30(6): 670-676.
Seetha Ram K V, Prasad Rama. Spatial Bjump at sudden channel enlargements with abrupt drop[J]. Journal of Hydraulic Engineering, 1998,124(6):643-646.
Hasan R, Matin A. Experimental study for sequent depth ratio of hydraulic jump in horizontal expanding channel[J]. Journal of Civil Engineering (IEB), 2009,37(1): 1-9.
Deng Jun, Xu Weilin, Zhang Jianming, et al. A new type of plunge pool—Multihorizontal submerged jets[J]. Science in China Series E, Technological Sciences, 2008,51(12): 2128-2141.
Rajaratnam N, Subramanya K. Hydraulic jumps below abrupt symmetrical expansions[J]. Journal of the Hydraulics Division, 1968,94(2):481-504.
Zare H K, Baddour R E. Threedimensional study of spatial submerged hydraulic jump[J]. Canadian Journal of Civil Engineering, 2007,34(9): 1140-1148.
Omid M H, Esmaeeli Varaki M, Narayanan R. Gradually expanding hydraulic jump in a trapezoidal channel[J]. Journal of Hydraulic Research, 2007,45(4): 512-518.
Kashefipour S M, Bakhtiari M. Hydraulic jump in a gradually expanding channel with different divergence angles[C]／／33rd IAHR Congress: Water Engineering for a Sustainable Environment. Vancouver, Canada：[s.n.], 2009:91-98.
Liu Chao, Jin Yan. Numerical simulation on three dimensional flow in twoway reversible pumping system[J]. Transactions of the Chinese Society for Agricultural Machinery, 2011,42(9): 74-78.(in Chinese)
刘沛清. 现代坝工消能防冲原理［M］. 北京: 科学出版社, 2010.
Chandra J, Lal P B. spatial hydraulic jump at axisymmetrical sudden expansions in rectangular channels[J]. Indian Journal of Power and River Valley Development, 1978,28(7): 183-188.