Abstract:Combining the common inner dissipation way of the orifice and the plug in water pipe or spillway with the dissipation way in free flow, the inner energy dissipater of tooth block was proposed, and the tooth block with different area contraction ratio by physical modeling experiment was studied to analyze its conveyance capacity, dissipation ratio, pressure changes along the tube and the characteristics of fluctuating pressure. The results show that the conveyance capacity of tooth block dissipater is mainly determined by the energy dissipater′s shape and size. The conveyance capacity is proportional to the area contraction ratio, while the energy dissipation ratio is opposite. The time-averaged pressure of schemes drops suddenly in contraction section, then gradually rises and returns to stability, and their recovering length is almost the same. The maximum point of pressure fluctuation appears at 1 time tunnel diameter away from outlet of the tooth block, and decreases rapidly along the tube, and then becomes stability after 4 times tunnel diameter. The tooth block with area contraction ratio of 0.471 2 has a better capacity of resisting cavitation than others as its pulsating strength is small, and its distribution of the probability density is approximate to Gauss distribution.
张婷, 田淳, 李永业, 尤志强, 樊盼. 齿墩状内消能工的消能及压力特性[J]. 排灌机械工程学报, 2014, 32(2): 136-139.
Zhang Ting, Tian Chun, Li Yongye, You Zhiqiang, Fan Pan. Characteristics of energy dissipation and pressure within inner energy dissipaters of tooth block. Journal of Drainage and Irrigation Machinery Engin, 2014, 32(2): 136-139.
[1]Qu Jingxue, Xu Weilin, Yang Yongquan, et al. Nume-rical simulation of flow through orifice energy-dissipators in Xiaolangdi flood-discharge tunnel [J]. Journal of Hydrodynamics, 2000, 12(3): 41-46.[2]刘善均, 杨永全, 许唯临,等. 洞塞泄洪洞的水力特性研究[J].水利学报, 2002, 33(7): 42-46. Liu Shanjun, Yang Yongquan, Xu Weilin, et al. Hydraulic characteristics of throat-type energy dissipater in discharge tunnel [J].Journal of Hydraulic Engineering, 2002, 33(7): 42-46.(in Chinese)[3]田忠.洞塞式内流消能工的水力特性研究[D].成都:四川大学水利水电学院,2006.[4]Tian Zhong, Xu Weilin, Wang Wei, et al. Hydraulic characteristics of plug energy dissipater in flood discharge tunnel [J].Journal of Hydrodynamics, 2009, 21(6):799-806.[5]张建民,许唯临,刘善均,等.突扩突缩式内流消能工的数值模拟研究[J].水利学报,2004, 35(12): 27-33. Zhang Jianmin, Xu Weilin, Liu Shanjun, et al. Nume-rical simulation of turbulent flow in throat type energy dissipators[J]. Journal of Hydraulic Engineering,2004, 35(12): 27-33.(in Chinese)[6]Wu Jianhua, Ai Wanzheng. Flows through energy dissipaters with sudden reduction and sudden enlargement forms [J]. Journal of Hydrodynamics, 2010, 22(3):360-365.[7]Fossa M, Guglielmini G.Pressure drop and void fraction profiles during horizontal flow through thin and thick orifices[J].Experimental Thermal and Fluid Science,2002,26(5):513-523.[8]Ramamurthi K, Nandakumar K.Characteristics of flow through small sharp-edged cylindrical orifices[J]. Flow Measurement and Instrumentation, 1999, 10(1):133-143.[9]Ai Wanzheng, Ding Tianming. Orifice plate cavitation mechanism and its influencing factors[J]. Water Science and Engineering, 2010, 3(3): 321-330.[10]何宁,赵振兴.孔板消能问题数值研究[J].水动力学研究与进展,2009,24(3):358-363. He Ning, Zhao Zhenxing. Numerical research on orifice energy dissipation [J]. Journal of Hydrodynamics, 2009, 24(3):358-363.(in Chinese)[11]赵振兴,何宁.孔板泄洪洞水流三维数值模拟研究[J].华北水利水电学院学报,2010,31(1):10-13. Zhao Zhenxing, He Ning. Numerical simulation of three-dimensional flow through flood-discharge tunnel with orifices [J]. Journal of North China Institute of Water Conservancy and Hydroelectric Power, 2010, 31(1):10-13.(in Chinese)[12]尹则高,朱慧洁,曹先伟,等. 二级洞塞泄流的消能特性分析[J].排灌机械工程学报,2012, 30(1): 85-90. Yin Zegao, Zhu Huijie,Cao Xianwei, et al. Analysis on discharge energy dissipation in two-stage plugs[J].Journal of Drainage and Irrigation Machinery Engineering,2012, 30(1):85-90.(in Chinese)[13]夏庆福,倪汉根.洞塞消能的数值模拟[J].水利学报,2003,34(8):37-42. Xia Qingfu, Ni Han′gen. Numerical simulation of plug energy dissipater [J]. Journal of Hydraulic Enginee-ring, 2003,34(8):37-42.(in Chinese)[14]廉玲军,王韦,徐威,等.洞塞泄洪洞的3维数值模拟研究[J].四川大学学报:工程科学版,2011,43(3):1-6. Lian Lingjun, Wang Wei, Xu Wei, et al. Numerical simulation of 3-D turbulent flows of plug discharge tunnel[J]. Journal of Sichuan University:Engineering Science Edition, 2011, 43(3): 1-6.(in Chinese)