基于表面粗糙度参数的管道当量粗糙度快速评测
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摘要
管道水力摩阻系数的精确取值是输水工程水力设计的重要前提,当量粗糙度k是计算水力摩阻系数的基础参数,然而传统的水力学试验方法检测k值需耗费较多的人、财、物、时。研究首先对3种不同粗糙度内衬的球墨铸铁管进行水力学性能的试验检测,基于不确定度理论给出合理的k值。在此基础上,采用触针式表面粗糙度仪对管道内壁的表面粗糙度参数进行检测,将检测结果与k值进行比较,结合国外已有试验数据,分析给出工程中管道k值的快速评测方法:当粗糙度轮廓的算术平均偏差Ra≤10μm或粗糙度轮廓的最大高度Rz≤50μm时,取样长度为lr=2.5 mm,采用中线制评定所得的Rz≈k,可使用Rz值代表k值对管道的水力性能进行评价。研究成果也可用于生产中管道内涂层加工质量的控制和提高。
The accurate friction factor of pipeline is an important prerequisite during the hydraulic designprocess of water conveyance project. The equivalent sand-grain roughness is a key parameter to calculatethe pipeline friction factor. However, it takes lots of manpower, material, financial resources and time tomeasure the equivalent sand-grain roughness by the traditional hydraulic test method. In this study, the hy-draulic performances of 3 kinds of ductile iron pipes with different coatings were tested, and the equivalentsand-grain roughness values were obtained based on the measure uncertainty analysis, respectively. Then,the inner wall surface roughness parameters of 3 kinds of pipes were detected by the E-35 B portable sur-face roughness tester profilometer. By the comparison of the surface roughness parameters and the equiva-lent sand-grain roughness k, and the reanalysis of others researcher's data, a quick evaluation method ofpipe equivalent sand-grain roughness based on the surface roughness parameters was given: when the arith-metical mean deviation of roughness profile Ra≤10μm or the maximum height of roughness profile Rz≤50μm, the sampling length of roughness profile lr set to 2.5 mm, then Rz≈k. So, the equivalentsand-grain roughness k in the Colebrook-White formula was replaced with Rz, and the friction factor canbe calculated. The research results can also be used to control and improve the coating quality of pipeline.
The accurate friction factor of pipeline is an important prerequisite during the hydraulic designprocess of water conveyance project. The equivalent sand-grain roughness is a key parameter to calculatethe pipeline friction factor. However, it takes lots of manpower, material, financial resources and time tomeasure the equivalent sand-grain roughness by the traditional hydraulic test method. In this study, the hy-draulic performances of 3 kinds of ductile iron pipes with different coatings were tested, and the equivalentsand-grain roughness values were obtained based on the measure uncertainty analysis, respectively. Then,the inner wall surface roughness parameters of 3 kinds of pipes were detected by the E-35 B portable sur-face roughness tester profilometer. By the comparison of the surface roughness parameters and the equiva-lent sand-grain roughness k, and the reanalysis of others researcher's data, a quick evaluation method ofpipe equivalent sand-grain roughness based on the surface roughness parameters was given: when the arith-metical mean deviation of roughness profile Ra≤10μm or the maximum height of roughness profile Rz≤50μm, the sampling length of roughness profile lr set to 2.5 mm, then Rz≈k. So, the equivalentsand-grain roughness k in the Colebrook-White formula was replaced with Rz, and the friction factor canbe calculated. The research results can also be used to control and improve the coating quality of pipeline.
引文
[1]李炜,徐孝平.水力学[M].武汉:武汉水利电力大学出版社,2000.
[2]HAMAF R.Boundary-Layer Characteristics for Rough and Smooth Surfaces[C]//Transactions of the Society of Naval Architects and Marine Engineers,1954.
[3]ZAGAROLA M V,SMITS A J.Mean-flow scaling of turbulent pipe flow[J].Journal of Fluid Mechanics,1998,37:33-79.
[4]ALLEN J J,SHOCKLING M A,KUNKEL G J,et al.Turbulent flow in smooth and rough pipes[J].Philosophical Transactions of the Royal Society,2007,365:699-714.
[5]LANGELANDSVIK L I,KUNKEL G J,SMISTS A J.Flow in a commercial steel pipe[J].Journal of Fluid Mechanics,2008,595:323-339.
[6]SLETFJERDING E.Friction Factor in Smooth and Rough Gas Pipeline[D].Trondheim:Norwegian University of Science and Technology,1999.
[7]SLETFJERDING E,GUDMUNDSSON J S.Friction factor directly from roughness measurements[J].Journal of Energy Resources Technology,2003,125(2):126-130.
[8]FARSHAD F F,RIEKE H H.Technology innovation for determining surface roughness in pipes[J].Journal of Petroleum Technology,2005,57(10):82-85.
[9]FARSHAD F F,PESACRETA T C.Coated pipe interior surface roughness as measured by three scanning probe instruments[J].Anti-Corrosion Methods and Materials,2003,50(1):6-16.
[10]FARSHAD F F,PESACRETA T C,GARBER J D,et al.A Comparison of surface roughness of pipes as measured by two profilometers and atomic force microscopy[J].The Journal of Scanning Microscopies,2001,23(4):241-248.
[11]郑双凌,马吉明,南春子.预应力钢筒混凝土管(PCCP)的阻力系数与粗糙度研究[J].水力发电学报,2012,31(3):126-130.
[12]杨开林,郭永鑫,付辉,等.管道当量粗糙度的率定及不确定度[J].水利学报,2012,43(12):1397-1404.
[13]国家质量技术监督局计量司.测量不确定度评定与表示指南[M].北京:中国计量出版社,2000.
[14]GB/T 3505-2009,产品几何技术规范(GPS)表面结构轮廓法术语、定义及表面结构参数[S].
[15]GB/T 10610-2009,产品几何技术规范(GPS)表面结构轮廓法评定表面结构的规则和方法[S].
[2]HAMAF R.Boundary-Layer Characteristics for Rough and Smooth Surfaces[C]//Transactions of the Society of Naval Architects and Marine Engineers,1954.
[3]ZAGAROLA M V,SMITS A J.Mean-flow scaling of turbulent pipe flow[J].Journal of Fluid Mechanics,1998,37:33-79.
[4]ALLEN J J,SHOCKLING M A,KUNKEL G J,et al.Turbulent flow in smooth and rough pipes[J].Philosophical Transactions of the Royal Society,2007,365:699-714.
[5]LANGELANDSVIK L I,KUNKEL G J,SMISTS A J.Flow in a commercial steel pipe[J].Journal of Fluid Mechanics,2008,595:323-339.
[6]SLETFJERDING E.Friction Factor in Smooth and Rough Gas Pipeline[D].Trondheim:Norwegian University of Science and Technology,1999.
[7]SLETFJERDING E,GUDMUNDSSON J S.Friction factor directly from roughness measurements[J].Journal of Energy Resources Technology,2003,125(2):126-130.
[8]FARSHAD F F,RIEKE H H.Technology innovation for determining surface roughness in pipes[J].Journal of Petroleum Technology,2005,57(10):82-85.
[9]FARSHAD F F,PESACRETA T C.Coated pipe interior surface roughness as measured by three scanning probe instruments[J].Anti-Corrosion Methods and Materials,2003,50(1):6-16.
[10]FARSHAD F F,PESACRETA T C,GARBER J D,et al.A Comparison of surface roughness of pipes as measured by two profilometers and atomic force microscopy[J].The Journal of Scanning Microscopies,2001,23(4):241-248.
[11]郑双凌,马吉明,南春子.预应力钢筒混凝土管(PCCP)的阻力系数与粗糙度研究[J].水力发电学报,2012,31(3):126-130.
[12]杨开林,郭永鑫,付辉,等.管道当量粗糙度的率定及不确定度[J].水利学报,2012,43(12):1397-1404.
[13]国家质量技术监督局计量司.测量不确定度评定与表示指南[M].北京:中国计量出版社,2000.
[14]GB/T 3505-2009,产品几何技术规范(GPS)表面结构轮廓法术语、定义及表面结构参数[S].
[15]GB/T 10610-2009,产品几何技术规范(GPS)表面结构轮廓法评定表面结构的规则和方法[S].