Numerical Investigation of Leakage from Steel Pipes Submerged in Water Based on the Experimental Results of Non-submerged Pipes

Document Type : Research Article

Authors

1 Ph.D. Student, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran

2 Professor, Center of Excellence for Engineering and Management of Civil Infrastructures, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran.

3 M.Sc., Islamic Azad University, Tehran Central Branch, Tehran, Iran.

Abstract

Few studies are made about the effect of environmental conditions on the leakage flow rate. Some of these researches show that environmental conditions play an important role in leakage flow rate. On the contrary, there are other researches opposing this idea. The purpose of this research is to investigate evidence of the effect of environmental conditions on leakage flow rate. Based on this idea, some tests were carried out in the college of engineering at the university of Tehran, using a circular experimental set up at high pressure discharging to the atmosphere. Various ranges of pressure up to 50 m of water were imposed on a 110 mm diameter aged steel pipe with some holes on the pipe surface. In the next step, by using the experimental results, an analytical model in ANSYS software was developed and outputs were compared with experimental data. Later a proper mathematical turbulent model was derived. Furthermore, the effect of submerged conditions was investigated by this appropriate numerical model. The results of this research showed that static pressure fluctuations in submerged jet had significant effect on discharge and the rate of leakage was reduced in comparison with atmospheric discharge. According to the results, pressure reduction in 5 m head pressure could affect the leakage discharge under submerged condition up to 55 percent when compared with the case of discharging to the atmosphere. With pressures above 20 m, smaller changes were observed. These changes were limited to less than 10 percent. The aforementioned reduction depended on the imposed head of water at leakage point and pressure value inside the pipe. Finally, a relationship between leakage outflow and internal pressure of pipe was proposed.
 

Keywords

References

ببران، ص. و هنر بخش، ن. (1387). "بحران وضعیت آب در جهان و ایران"، فصلنامه راهبرد، سال شانزدهم، شماره 48، ص‌ص. 193-212.
تابش، م. (1395). مدل‌سازی پیشرفته شبکه‌های توزیع آب، انتشارات دانشگاه تهران، تهران، ایران.
شرکت مهندسی آب و فاضلاب کشور. (1393). شاخص آب بدون درآمد، آدرس سایت http://www.moe.gov.ir.
معاونت برنامه‌ریزی و نظارت راهبردی نهاد ریاست جمهوری. (1391). راهنمای شناخت و بررسی عوامل مؤثر در آب به‌حساب نیامده و راهکارهای کاهش آن، نشریه شماره 556، تهران، ایران.
Albertson, M. L., Dai, Y. B., Jensen, R. A., and Rouse, H., (1950). “Diffusion of submerged jets”, Transactions of the American Society of Civil Engineers, 115(1), 639-664.
American Water Works Association (AWWA), (1999). Water conservation guide bookNo. 5, Water audits and leak detection, American water works association (California-Nevada section) and Department of Water Resources Water Conservation Office.
Cassa, A. M., van Zyl, J. E., and Laubscher, R. F. (2006). “A numerical investigation into the behaviour of leak openings in UPVC pipes under pressure”, In WISA2006 the Water Institute of Southern Africa Biennial Conference and Exhibition, South Africa.
Cassa, A. and van Zyl, J. (2008). “A numerical investigation into the behaviour of cracks in UPVC pipes under pressure”, 10th Annual Water Distribution Systems Analysis Conference, Kruger National Park, South Africa.
Cassa, A. M., van Zyl, J. E., and Laubscher, R. F. (2010). “A numerical investigation into the effect of pressure on holes and cracks in water supply pipes”, Urban Water Journal, 7(2), 109-120.
Cassa, A. M., and van Zyl, J. E. (2013). “Predicting the head-leakage slope of cracks in pipes subject to elastic deformations”, Journal of Water Supply: Research and Technology- AQUA, 62(4), 214-223.
Coetzer, A. J., van Zyl, J. E., and Clayton, C. R. I., (2006). “An experimental investigation into the turbulent-flow hydraulics of small circular holes in plastic pipes”, In 8th Annual Water Distribution Systems Analysis Symposium, Cincinnati, Ohio, U.S.A.
De Paola, F., Galdiero, E., Giugni, M., Papa, R., and Urciuoli, G. (2014). “Experimental investigation on a buried leaking pipe”, Procedia Engineering, 89, 298-303.
Farley, M., and Trow, S. (Eds.)., (2003). Losses in water distribution networks: a practitioner's guide to assessment, monitoring and control, IWA Publishing. 
Ferrante, M., Massari, C., Cluni, F., Brunone, B., and Meniconi, S. (2009). “Leak discharge and strains in a polyethylene pipe”, Integrating Water Systems, 203-208, Laiden, Netherlands.
Ferrante, M., Massari, C., Brunone, B., and Meniconi, S. (2011). “Experimental evidence of hysteresis in the head–discharge relationship for a leak in a polyethylene pipe”, Journal of Hydraulic Engineering, 137(7), 775–780.
Ferrante, M. (2012). “Experimental investigation of the effects of pipe material on the leak head-discharge relationship”, Journal of Hydraulic Engineering, 138(8), 736–743.
Fox, S., Collins, R., and Boxall, J. (2016). “Physical investigation into the significance of ground conditions on dynamic leakage behaviour”, Journal of Water Supply: Research and Technology-AQUA, 65(2), 103-115.
Franchini, M., and Lanza, L., (2014). “Leakages in pipes: generalizing Torricelli's equation to deal with different elastic materials, diameters and orifice shape and dimensions”, Urban Water Journal, 11(8), 678-695.
Greyvenstein, B., and Zyl, J. V., (2007). “An experimental investigation into the pressure-leakage relationship of some failed water pipes”, Aqua-Journal of Water Supply, 56(2), 117-124.
Guo, S., Zhang, T. Q., Shao, W. Y., Zhu, D. Z., and Duan, Y. Y., (2013). “Two-dimensional pipe leakage through a line crack in water distribution systems”, Journal of Zhejiang University SCIENCE A, 14(5), 371-376.
Kingdom, B., Limberger, R. and Marin, P., (2006). “The challenge of reducing non-revenue water (nrw) in developing countries: how the private sector can help: a look at performance- based service contracting”, Water Supply and Sanitation Sector Board Discussion Paper Series, 8, 1-52.
Lambert, A., (1997). “Pressure management / leakage relationships: theory, concepts and practical applications”, Proceeding of Minimizing Leakage in Water Supply / Distribution Systems, IQPC Seminar, London.
Massari, C. (2012). “Diagnosis and hydraulic characterization of pressurized pipe systems”, Ph.D. Thesis, Department of Civil and Environmental Engineering, University of Perugia, Italy.Massari, C., Ferrante, M., Brunone, B., and Meniconi, S. (2012). “Is the leak head–discharge relationship in polyethylene pipes a bijective function?”, Journal of Hydraulic Research, 50(4), 409-417.
Tabesh, M., (1998). “Implications of the pressure dependency of outflows on data management, mathematical modelling and reliability assessment of water distribution systems”, Ph.D. Thesis,
Department of Civil Engineering, University of Liverpool, England.
Thornton, J., and Lambert, A., (2005). “Progress in practical prediction of pressure: leakage, pressure: burst frequency and pressure: consumption relationships”, Paper to IWA Special Conference ‘Leakage 2005’, Halifax, Canada.
Walski, T., Whitman, B., Baron, M., and Gerloff, F., (2009). “Pressure vs. flow relationship for pipe leaks”, World Environmental and Water Resources Congress, Kansas City, Missouri, U.S.A.
World Health Organization (WHO), (2001). Leakage management and control– a best practice manual, WHO, Geneva.

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History

  • Receive Date: 15 March 2016
  • Revise Date: 25 February 2017
  • Accept Date: 08 March 2017

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