尾坎位置对坎式阶梯溢洪道水力特性影响研究
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摘要
坎式阶梯溢洪道具有较高的掺气效率,然而目前为止对其详细流场结构以及消能特性开展的研究尚不多见。为此结合VOF法,采用标准k-ε紊流模型对带尾坎的阶梯溢洪道进行了三维数值模拟,研究了不同尾坎位置对其水力特性的影响。结果表明:随着尾坎向上游移动,水面线和尾坎下游侧的旋涡大小均无明显变化,但尾坎上游侧的旋涡尺度逐渐减小;对于不同体型,同一台阶凸角上流速呈先增加后不变的规律,而对于同一体型,下游台阶凸角上流速大于上游的;台阶水平面上最大压强先增加后不变,台阶竖直面上最小压强逐渐减小,而尾坎下游侧竖直面上最小压强则呈增加的趋势;台阶面上最大紊动能耗散率逐渐增加,而尾坎上的则相反,总的消能率变化甚微。
Stepped spillway has high aeration efficiency, but little research has been done on its detailed flow field structure and energy dissipation characteristics. In this paper, combined with VOF method, the three-dimensional numerical simulation of stepped spillway with tail bucket was carried out by using standard k-ε turbulence model, and the influence of different tail bucket positions on its hydraulic characteristics was studied. The results showed that with the tail bucket moving to upstream, the vortex size near the water surface and the lower side of the tail bucket didn't change obviously, but the vortex scale on the upper side of the tail bucket decreased gradually. For different body types, the velocity on the convex angle of the same step increased at first and then remained unchanged, and for the same body type, the velocity on the convex angle of the downstream step was larger than that on the upstream step. The maximum pressure on the horizontal surface of the step increased at first and then didn't change, the minimum pressure on the vertical surface of the step decreased gradually while the minimum pressure on the vertical surface of the downstream side of the tail ridge tended to increase. The maximum turbulent energy dissipation rate on the step surface increased gradually. On the contrary, the total energy dissipation rate changed little on the tail bucket.
Stepped spillway has high aeration efficiency, but little research has been done on its detailed flow field structure and energy dissipation characteristics. In this paper, combined with VOF method, the three-dimensional numerical simulation of stepped spillway with tail bucket was carried out by using standard k-ε turbulence model, and the influence of different tail bucket positions on its hydraulic characteristics was studied. The results showed that with the tail bucket moving to upstream, the vortex size near the water surface and the lower side of the tail bucket didn't change obviously, but the vortex scale on the upper side of the tail bucket decreased gradually. For different body types, the velocity on the convex angle of the same step increased at first and then remained unchanged, and for the same body type, the velocity on the convex angle of the downstream step was larger than that on the upstream step. The maximum pressure on the horizontal surface of the step increased at first and then didn't change, the minimum pressure on the vertical surface of the step decreased gradually while the minimum pressure on the vertical surface of the downstream side of the tail ridge tended to increase. The maximum turbulent energy dissipation rate on the step surface increased gradually. On the contrary, the total energy dissipation rate changed little on the tail bucket.
引文
[1] Thorwarth J.Hydraulics of pooled stepped spillways—Self-induced unsteady flow and energy dissipation[D].Aachen:University of Aachen,2008.
[2] André S.High velocity aerated flows on stepped chutes with macro-roughness elements[D].Lausanne:Laboratoire de Constructions Hydrauliques (LCH),2004.
[3] K kpinar M A.Flow over a stepped chute with and without macro-roughness elements[J].Canadian Journal of Civil Engineering,2004,31(5):880-891.
[4] Felder S,Chanson H.Aeration,flow instabilities,and residual energy on pooled stepped spillways of embankment dams[J].Journal of Irrigation & Drainage Engineering,2013,139(10):880-887.
[5] Emiroglu M E,Baylar A.An investigation of effect of stepped chutes with end sill on aeration performance[J].Water Quality Research Journal of Canada,2003,38(3):1097-1102.
[6] Felder S,Fromm C,Chanson H.Air entrainment and energy dissipation on a 8.9° slope stepped spillway with flat and pooled steps[R].Queensland:The University of Queensland,2012.
[7] Zare H K,Doering J C.Inception point of air entrainment and training wall characteristics of baffles and sills on stepped spillways[J].Journal of Hydraulic Engineering,2012,138(12):1119-1124.
[8] Li S,Zhang J,Xu W.Numerical investigation of air–water flow properties over steep flat and pooled stepped spillways[J].Journal of Hydraulic Research,2018(2):1-14.
[9] Felder S,Guenther P,Hubert C.Air-water flow properties and energy dissipation on stepped spillways:a physical study of several pooled stepped configurations[R].Queensland:The University of Queensland,2012.
[10] 徐鹏,赵信峰,白兆亮.倒V形阶梯与传统阶梯流场特性对比研究[J].水资源与水工程学报,2017,28(5):180-185.
[11] 靳晟,李琳.基于数值模拟的某阶梯溢洪道方案优化研究[J].水资源与水工程学报,2013,24(5):17-22.
[12] 高梦露,刘亚坤,孙洪亮,等.阶梯式溢洪道的数值模拟研究[J].水利与建筑工程学报,2015(2):28-32.
[13] 耿敬,马世领,李刚,等.龙头桥水库溢洪道流场数值模拟及优化研究[J].水力发电学报,2017,36(10):74-83.
[14] 李登松,杨庆,范鹏源,等.曲线型局部超高阶梯溢洪道的水力特性[J].工程科学与技术,2018(4):81-86.
[15] 钟晓凤,张法星,孙宁,等.某水库阶梯溢洪道水力特性研究[J].人民黄河,2016,38(6):115-118.
[16] 向蕾.溢洪道挑流消能段水气两相流的数值模拟[J].人民长江,2016,47(S1):161-163.
[17] 张一,刘韩生.察汗乌苏溢洪道流场二维和三维数值模拟对比[J].人民长江,2010,41(8):89-91.
[18] 王继保,张守磊.威远江水电站溢洪道挑流鼻坎数值模拟研究[J].人民长江,2010,41(8):92-95.
[19] Celik I B,Ghia U,Roache P J,et al.Procedure of estimation and reporting of uncertainty due to discretization in CFD applications[J].Journal of Fluids Engineering,2008,130(7):78001-78004.
[2] André S.High velocity aerated flows on stepped chutes with macro-roughness elements[D].Lausanne:Laboratoire de Constructions Hydrauliques (LCH),2004.
[3] K kpinar M A.Flow over a stepped chute with and without macro-roughness elements[J].Canadian Journal of Civil Engineering,2004,31(5):880-891.
[4] Felder S,Chanson H.Aeration,flow instabilities,and residual energy on pooled stepped spillways of embankment dams[J].Journal of Irrigation & Drainage Engineering,2013,139(10):880-887.
[5] Emiroglu M E,Baylar A.An investigation of effect of stepped chutes with end sill on aeration performance[J].Water Quality Research Journal of Canada,2003,38(3):1097-1102.
[6] Felder S,Fromm C,Chanson H.Air entrainment and energy dissipation on a 8.9° slope stepped spillway with flat and pooled steps[R].Queensland:The University of Queensland,2012.
[7] Zare H K,Doering J C.Inception point of air entrainment and training wall characteristics of baffles and sills on stepped spillways[J].Journal of Hydraulic Engineering,2012,138(12):1119-1124.
[8] Li S,Zhang J,Xu W.Numerical investigation of air–water flow properties over steep flat and pooled stepped spillways[J].Journal of Hydraulic Research,2018(2):1-14.
[9] Felder S,Guenther P,Hubert C.Air-water flow properties and energy dissipation on stepped spillways:a physical study of several pooled stepped configurations[R].Queensland:The University of Queensland,2012.
[10] 徐鹏,赵信峰,白兆亮.倒V形阶梯与传统阶梯流场特性对比研究[J].水资源与水工程学报,2017,28(5):180-185.
[11] 靳晟,李琳.基于数值模拟的某阶梯溢洪道方案优化研究[J].水资源与水工程学报,2013,24(5):17-22.
[12] 高梦露,刘亚坤,孙洪亮,等.阶梯式溢洪道的数值模拟研究[J].水利与建筑工程学报,2015(2):28-32.
[13] 耿敬,马世领,李刚,等.龙头桥水库溢洪道流场数值模拟及优化研究[J].水力发电学报,2017,36(10):74-83.
[14] 李登松,杨庆,范鹏源,等.曲线型局部超高阶梯溢洪道的水力特性[J].工程科学与技术,2018(4):81-86.
[15] 钟晓凤,张法星,孙宁,等.某水库阶梯溢洪道水力特性研究[J].人民黄河,2016,38(6):115-118.
[16] 向蕾.溢洪道挑流消能段水气两相流的数值模拟[J].人民长江,2016,47(S1):161-163.
[17] 张一,刘韩生.察汗乌苏溢洪道流场二维和三维数值模拟对比[J].人民长江,2010,41(8):89-91.
[18] 王继保,张守磊.威远江水电站溢洪道挑流鼻坎数值模拟研究[J].人民长江,2010,41(8):92-95.
[19] Celik I B,Ghia U,Roache P J,et al.Procedure of estimation and reporting of uncertainty due to discretization in CFD applications[J].Journal of Fluids Engineering,2008,130(7):78001-78004.