横向射流影响管内水流压力的实验研究
摘要
输水管路的三通结构是城市供水管路系统的重要组成部分,当主管截面积大于支管截面积时,可将支管视作横向射流。在有压管路的设计计算中经常需要考虑到管路的压力损失以及产生管道压降等的相关因素,尤其是对于较短三通汇流管道和汇流节点较多的管路系统,更需要考虑其汇流处的压力场分布情况,在这种条件下,对射流流场压力特性的探究显得尤为重要。
本文采用实验方法对管内横向射流的压力场进行实验研究,在射流入射方向与主流之间的角度为90°,且射流速度是主流速度的1~6倍的情况下,测量了射流截面以及主流方向上流体的压力值分布情况。测量结果显示,在射流截面上,入射口附近有一个对称分布的压力相对较低的区域;在主流方向上则有一个向下游偏斜分布的压力相对较低的区域。研究表明,入射流体在横流的作用下,其迎流面与背流面会产生压力差,这使得射流主轴线向下游弯曲。而对于本实验条件下的横向射流,由于管道的约束,射流的弯曲程度会比无约束条件下的横向射流更加明显。
分析表明,对于有压管道内的横向射流,管道入射口附近存在一个向下游偏斜的射流核心区,该射流核心仅影响入射口附近区域,在射流核心区内,入射流体的动能没有全部转换为压力能;在射流核心区之外,入射的动能全部转换为压力能,使管道内部流体压力产生大幅提升,管内流体压力的增量与射流速度的二次方相关。
For the shorter three-way structure pipelines and the pipelines have more confluence nodes, the flow characteristics similar to jet-into-crossflow, the pressure distribution characteristics of the jet flow field is particularly important to explore. In this paper, an experimantal investigation was performed to a single jet issuing into a constant flow in a pipe.
The pressure distribution on jet cross section and the pressure distribution of the mainstream were measured under the condition of having a right angle between the jet and the mainstream, as well as having the speed of jet which was 1 to 6 times of the mainstream’s. After, according to the fluid momentum relationship of the confluence of main pipe and branch in pressure pipe, analysed the changes situation of the pressure incremental caused by jet.
The measurement results shown that,near the entrance port existed a symmetrical distribution of relatively low pressure region on jet cross section. Along the direction of the mainstream,near the entrance port existed a relatively low pressure region with skewing to downstream. The studies shown that, because of the role of cross-flow, emerged a pressure difference between front and back interface of jet on direction of the mainstream, and the main axis of jet skew to the downstream. Under the experimental conditions of this paper, because of the constraint of pipe, the jet was more curved than the jet with no constraint.
The analysis shown that, near the entrance port existed a jet core with skewing to downstream, the jet core only affect the region near the entrance port. In the jet core region, not all of the incident kinetic energy was converted to pressure energy in the core. Outside the the core, all of the incident kinetic energy was converted to pressure energy, caused the pressure of the flow inside of the pipe has been increased significantly by the incident flow, the pressure increment correlated with the jet velocity’s quadratic dependence.
本文采用实验方法对管内横向射流的压力场进行实验研究,在射流入射方向与主流之间的角度为90°,且射流速度是主流速度的1~6倍的情况下,测量了射流截面以及主流方向上流体的压力值分布情况。测量结果显示,在射流截面上,入射口附近有一个对称分布的压力相对较低的区域;在主流方向上则有一个向下游偏斜分布的压力相对较低的区域。研究表明,入射流体在横流的作用下,其迎流面与背流面会产生压力差,这使得射流主轴线向下游弯曲。而对于本实验条件下的横向射流,由于管道的约束,射流的弯曲程度会比无约束条件下的横向射流更加明显。
分析表明,对于有压管道内的横向射流,管道入射口附近存在一个向下游偏斜的射流核心区,该射流核心仅影响入射口附近区域,在射流核心区内,入射流体的动能没有全部转换为压力能;在射流核心区之外,入射的动能全部转换为压力能,使管道内部流体压力产生大幅提升,管内流体压力的增量与射流速度的二次方相关。
For the shorter three-way structure pipelines and the pipelines have more confluence nodes, the flow characteristics similar to jet-into-crossflow, the pressure distribution characteristics of the jet flow field is particularly important to explore. In this paper, an experimantal investigation was performed to a single jet issuing into a constant flow in a pipe.
The pressure distribution on jet cross section and the pressure distribution of the mainstream were measured under the condition of having a right angle between the jet and the mainstream, as well as having the speed of jet which was 1 to 6 times of the mainstream’s. After, according to the fluid momentum relationship of the confluence of main pipe and branch in pressure pipe, analysed the changes situation of the pressure incremental caused by jet.
The measurement results shown that,near the entrance port existed a symmetrical distribution of relatively low pressure region on jet cross section. Along the direction of the mainstream,near the entrance port existed a relatively low pressure region with skewing to downstream. The studies shown that, because of the role of cross-flow, emerged a pressure difference between front and back interface of jet on direction of the mainstream, and the main axis of jet skew to the downstream. Under the experimental conditions of this paper, because of the constraint of pipe, the jet was more curved than the jet with no constraint.
The analysis shown that, near the entrance port existed a jet core with skewing to downstream, the jet core only affect the region near the entrance port. In the jet core region, not all of the incident kinetic energy was converted to pressure energy in the core. Outside the the core, all of the incident kinetic energy was converted to pressure energy, caused the pressure of the flow inside of the pipe has been increased significantly by the incident flow, the pressure increment correlated with the jet velocity’s quadratic dependence.
引文
[1]水利水电规划设计总院,水利水电地下建筑情报网.水利水电工程地下建筑物设计手册[M].成都:四川科学技术出版社,1993.
[2]平浚.射流理论基础及应用[M]. 1版.北京:宇航出版社,1995.
[3] A.J.Reynods. Observations of liquid-into-liquid jet[J]. Cavendish Laboratory,1962.
[4] K.J.Mcnaughton,C.G.Sinclair. Submerged jets in short cylindrical flow vessls[J]. Journal of Fluid Mechanics,1966(25):367-376.
[5] Pratte B .D,Baines W.D. Profiles of the round turbulent jet in a crossflow[J]. Journal of the Hydraulics Division,ASCE,1967(93):53-64.
[6] Subramananga K,Porey P D. Trajectory of a turbulent cross jet[J]. Journal of Hydraulic research,1984(22):343-354.版) ,1986(3):9-19.
[7]徐孝平.横向淹没射流和表面射流问题[J].武汉大学学报(工学),1986(3):9-19.
[8]肖佐庭,周炳良,余常昭.淹没的水平热射流在横流中扩散特性的实验研究[J].水力发电学报,1987(3):49-61.
[9] Sobey Rodney J,Kean Richarl D. Horizontal round buoyant jet in shallow water[J]. Journal of Hydraulic Engineering,1988,114(8):910-929 .
[10]熊熬魁,詹德新,全贵均,等.近水面淹没喷嘴射流流场特性的实验研究[J].水动力学研究与进展,1995,10(4):429-433.
[11] J.W.Ramsey,R.J.Goldstein. Interaction of a Heated Jet With a Deflecting Stream[J]. Journal of Heat Transfer,1971,93(4):365-373.
[12] G.W.Rankin,K.Sidhar,M.Arulaja,K.R.Kumar. An experimental investigation of laminar axisymmetric submerged jets[J]. Journal of Fluid Mechanics ,1983(133): 217-231.
[13] Subhasish Dey,Arindam Sarkar. Characteristics of submerged jets in evolving scour hole dowmstream of an apron[J]. Journal of Engineering Mechanics,2008,134(11):927-937.
[14] Jian Hong-sun,Chin-Tasu Hsu. Flow Visualization of Submerged Jets in Narrow Channels[J]. Modern Physics Letters B,2009,23(3):377-380.
[15] L.P.Xia,K.M.Lam. Velocity and concentration measurements in initial region of submerged round jets in stagnant environment and in coflow[J]. Journal of Hydro-environment Research,2009,3(1):21-34.
[16] V.P.Karlikov,S.L.Tolokonnikov,O.V.Trushina. Possible Classification of the Self-Oscillatory Spouting Regimes of Plane Vertical Submerged Jets of a Heavy Fluid[J]. Fluid Dynamics,2009,44(3):351–361.
[17]槐文信,那宇彤,童汉毅,等.静止浅水环境中铅垂紊动射流的试验研究[J].水利学报,2002(9):32-36.
[18]肖洋,唐洪武,华明,王志良.同向圆射流混合特性实验研究[J].水科学进展,2006,17(4):512-517.
[19]许多鸣,余常昭.平面水射流对槽底的冲击压强及其脉动特性[J].水利学报,1983(5):52-58.
[20]董志勇,等.掺气对射流冲击水垫塘底部动水压强的影响,中国科学(A辑),1994,24(4):431-439.
[21]田中,许唯临,王韦,等.高速淹没冲击射流的压强特性[J].水利学报. 2005,36(4):401-404.
[22]胡鹤鸣,陈永灿,李玲,等.旋转水射流冲击压强的实验分析[J].长江流域资源与环境,2007,16(1):42-47.
[23]李艳玲,华国春,张建民,杨永全,胡耀华.单层多股和多层多股水平淹没射流的消能特性分析[J].水动力学研究与进展,2006,21(1):26-31.
[24]茅泽育,罗昇,罗以.圆形管道90°汇流口局部能量损失[J].河海大学学报(自然科学版),2006,34(4):387-391.
[25]茅泽育,罗昇,赵凯,姚程.矩形断面压力管道汇流口局部能量损失[J].水利水电科技进展,2006,26(3):62-66.
[26]茅泽育,赵凯,赵璇,等.管道汇流口局部阻力试验研究[J].水利学报,2007,38(7):812-818.
[27]槐文信,李炜.径向射流的相似分析[J].水利学报,1992(9):50-58.
[28]槐文信,李炜,彭文启.横流中单圆孔紊动射流计算与特性分析[J].水利学报,1998(4):8-15.
[29]张晓元,李炜,李长城.横流环境中射流的数值研究[J].水利学报,2002(3):32-38+43.
[30] Xia L P. An experimental and numerical investigation of a turbulent round jet issuing into an unsteady crossflow [D] . Hong Kong :The University of Hong Kong,1998.
[31]夏丽萍,林杰明,杨志峰,等.圆射流在非恒定横向流中的掺混扩散[J].水利学报,2001(5):82-88.
[32]周连伟.三维非恒定流场中圆形浮射流的数值模拟研究[D].大连:大连理工大学,2004.
[33]马健.纯射流在非恒定横流中的流动特性研究[D].浙江:浙江大学,2006.
[34] Lauder B.E,Spalding D.B. The numerical calculation of turbulent flows[J]. Computation Methods in Applied Mechanics and Engineering,1974,3(2):269-289.
[35] V.Yakhot , S.A.Orzag. Renormalization-group analysis of turbulence[J]. Applied and Computational Mathematics,1986,57(14):1722-1724.
[36] C.G. Speziale,S. Thangam.Analysis of an RNG based turbulence model for separated flows[J],International Journal of Engineering Science,1992,30(10):1379-1388.
[37]曲延鹏,陈颂英,王小鹏,腾书格.不同湍流模型对圆射流数值模拟的讨论[J].工程热物理学报,2008,29(6):959-957.
[38]卜琳,李会雄,王海军,陈听宽.斜向三通管内射流混合特性的三维数值模拟[J].核动力工程,2008,29(5):124-128.
[39]江山,张京伟,吴崇健,许清,彭文波.基于FLUENT的90°圆形弯管内部流场分析[J].中国舰船研究,2008,3(1):37-41
[40]周承福,陈小榆,刘德生,宋文涛.三通管二维湍流数值模拟[J].石油化工设备,2008,37(2):37-40.
[41]孙鑫. T型三通和圆弧型三通流场的试验研究及数值模拟[D].新疆:新疆农业大学,2009.
[2]平浚.射流理论基础及应用[M]. 1版.北京:宇航出版社,1995.
[3] A.J.Reynods. Observations of liquid-into-liquid jet[J]. Cavendish Laboratory,1962.
[4] K.J.Mcnaughton,C.G.Sinclair. Submerged jets in short cylindrical flow vessls[J]. Journal of Fluid Mechanics,1966(25):367-376.
[5] Pratte B .D,Baines W.D. Profiles of the round turbulent jet in a crossflow[J]. Journal of the Hydraulics Division,ASCE,1967(93):53-64.
[6] Subramananga K,Porey P D. Trajectory of a turbulent cross jet[J]. Journal of Hydraulic research,1984(22):343-354.版) ,1986(3):9-19.
[7]徐孝平.横向淹没射流和表面射流问题[J].武汉大学学报(工学),1986(3):9-19.
[8]肖佐庭,周炳良,余常昭.淹没的水平热射流在横流中扩散特性的实验研究[J].水力发电学报,1987(3):49-61.
[9] Sobey Rodney J,Kean Richarl D. Horizontal round buoyant jet in shallow water[J]. Journal of Hydraulic Engineering,1988,114(8):910-929 .
[10]熊熬魁,詹德新,全贵均,等.近水面淹没喷嘴射流流场特性的实验研究[J].水动力学研究与进展,1995,10(4):429-433.
[11] J.W.Ramsey,R.J.Goldstein. Interaction of a Heated Jet With a Deflecting Stream[J]. Journal of Heat Transfer,1971,93(4):365-373.
[12] G.W.Rankin,K.Sidhar,M.Arulaja,K.R.Kumar. An experimental investigation of laminar axisymmetric submerged jets[J]. Journal of Fluid Mechanics ,1983(133): 217-231.
[13] Subhasish Dey,Arindam Sarkar. Characteristics of submerged jets in evolving scour hole dowmstream of an apron[J]. Journal of Engineering Mechanics,2008,134(11):927-937.
[14] Jian Hong-sun,Chin-Tasu Hsu. Flow Visualization of Submerged Jets in Narrow Channels[J]. Modern Physics Letters B,2009,23(3):377-380.
[15] L.P.Xia,K.M.Lam. Velocity and concentration measurements in initial region of submerged round jets in stagnant environment and in coflow[J]. Journal of Hydro-environment Research,2009,3(1):21-34.
[16] V.P.Karlikov,S.L.Tolokonnikov,O.V.Trushina. Possible Classification of the Self-Oscillatory Spouting Regimes of Plane Vertical Submerged Jets of a Heavy Fluid[J]. Fluid Dynamics,2009,44(3):351–361.
[17]槐文信,那宇彤,童汉毅,等.静止浅水环境中铅垂紊动射流的试验研究[J].水利学报,2002(9):32-36.
[18]肖洋,唐洪武,华明,王志良.同向圆射流混合特性实验研究[J].水科学进展,2006,17(4):512-517.
[19]许多鸣,余常昭.平面水射流对槽底的冲击压强及其脉动特性[J].水利学报,1983(5):52-58.
[20]董志勇,等.掺气对射流冲击水垫塘底部动水压强的影响,中国科学(A辑),1994,24(4):431-439.
[21]田中,许唯临,王韦,等.高速淹没冲击射流的压强特性[J].水利学报. 2005,36(4):401-404.
[22]胡鹤鸣,陈永灿,李玲,等.旋转水射流冲击压强的实验分析[J].长江流域资源与环境,2007,16(1):42-47.
[23]李艳玲,华国春,张建民,杨永全,胡耀华.单层多股和多层多股水平淹没射流的消能特性分析[J].水动力学研究与进展,2006,21(1):26-31.
[24]茅泽育,罗昇,罗以.圆形管道90°汇流口局部能量损失[J].河海大学学报(自然科学版),2006,34(4):387-391.
[25]茅泽育,罗昇,赵凯,姚程.矩形断面压力管道汇流口局部能量损失[J].水利水电科技进展,2006,26(3):62-66.
[26]茅泽育,赵凯,赵璇,等.管道汇流口局部阻力试验研究[J].水利学报,2007,38(7):812-818.
[27]槐文信,李炜.径向射流的相似分析[J].水利学报,1992(9):50-58.
[28]槐文信,李炜,彭文启.横流中单圆孔紊动射流计算与特性分析[J].水利学报,1998(4):8-15.
[29]张晓元,李炜,李长城.横流环境中射流的数值研究[J].水利学报,2002(3):32-38+43.
[30] Xia L P. An experimental and numerical investigation of a turbulent round jet issuing into an unsteady crossflow [D] . Hong Kong :The University of Hong Kong,1998.
[31]夏丽萍,林杰明,杨志峰,等.圆射流在非恒定横向流中的掺混扩散[J].水利学报,2001(5):82-88.
[32]周连伟.三维非恒定流场中圆形浮射流的数值模拟研究[D].大连:大连理工大学,2004.
[33]马健.纯射流在非恒定横流中的流动特性研究[D].浙江:浙江大学,2006.
[34] Lauder B.E,Spalding D.B. The numerical calculation of turbulent flows[J]. Computation Methods in Applied Mechanics and Engineering,1974,3(2):269-289.
[35] V.Yakhot , S.A.Orzag. Renormalization-group analysis of turbulence[J]. Applied and Computational Mathematics,1986,57(14):1722-1724.
[36] C.G. Speziale,S. Thangam.Analysis of an RNG based turbulence model for separated flows[J],International Journal of Engineering Science,1992,30(10):1379-1388.
[37]曲延鹏,陈颂英,王小鹏,腾书格.不同湍流模型对圆射流数值模拟的讨论[J].工程热物理学报,2008,29(6):959-957.
[38]卜琳,李会雄,王海军,陈听宽.斜向三通管内射流混合特性的三维数值模拟[J].核动力工程,2008,29(5):124-128.
[39]江山,张京伟,吴崇健,许清,彭文波.基于FLUENT的90°圆形弯管内部流场分析[J].中国舰船研究,2008,3(1):37-41
[40]周承福,陈小榆,刘德生,宋文涛.三通管二维湍流数值模拟[J].石油化工设备,2008,37(2):37-40.
[41]孙鑫. T型三通和圆弧型三通流场的试验研究及数值模拟[D].新疆:新疆农业大学,2009.
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