Air Entrainment in Pipe-Filling Bores and Pressurization Interfaces
Publication: Journal of Hydraulic Engineering
Volume 146, Issue 2
Abstract
Certain closed conduits may undergo processes of rapid filling, in which the flow regime transits from open channel into pressurized flows. Air bubbles may be entrained through such pressurization interfaces, and this entrainment can have effects on the flow dynamics. Whereas air entrainment in static hydraulic jumps has been studied in closed conduits, such entrainment has not been investigated in moving pipe-filling bores. Experimental tests involving the creation of air-entraining pipe-filling bores were conducted, and key characteristics of the process were recorded. Theoretical propositions based on conservation laws are compared with results of experimental data to develop an expression to estimate air entrainment in the moving bores. The nondimensional dragged air flow rate in the two-phase flow generated by the jump is quantified based on a relatively small number of nondimensional parameters: supercritical Froude number, and the ratio between the bore velocity and the supercritical velocity, being grouped by the closed conduit slope. Agreement between the proposed expression and experimental data in terms of , the coeffcient of multiple determination in multiple regression, is good, and may indicate an alternative way to compute entrained air pocket volume during rapid filling processes.
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Data Availability Statement
Some or all data, models, or code generated or used during the study are available from the corresponding author by request (including analytical, numerical, and experimental test data).
Acknowledgments
The first author thanks the support of CNPq/Brazil, which, through process 307105/2015-6, allowed the collaborative study with Auburn University.
References
Baines, W. D. 1991. “Air cavities as gravity currents on slope.” J. Hydraul. Eng. 117 (12): 1600–1615. https://doi.org/10.1061/(ASCE)0733-9429(1991)117:12(1600).
Camino, G. A., D. Zhu, and N. Rajaratnam. 2015. “Flow observations in tall plunging flow dropshafts.” J. Hydraul. Eng. 141 (1): 06014020. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000939.
Chanson, H. 2004. “Hydraulics of rectangular dropshafts.” J. Irrig. Drain. Eng. 130 (6): 523–529. https://doi.org/10.1061/(ASCE)0733-9437(2004)130:6(523).
Chanson, H., and C. Gualtieri. 2008. “Similitude and scale effects of air entrainment in hydraulic jumps.” J. Hydraul. Res. 46 (1): 35–44. https://doi.org/10.1080/00221686.2008.9521841.
Chosie, C. D., T. M. Hatcher, and J. G. Vasconcelos. 2014. “Experimental and numerical investigation on the motion of discrete air pockets in pressurized water flows.” J. Hydraul. Eng. 140 (8): 04014038. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000898.
Ead, S. A., and N. Rajaratnam. 2002. “Hydraulic jumps on corrugated beds.” J. Hydraul. Eng. 128 (7): 656–663. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:7(656).
Elevatorski, E. A. 1959. Hydraulic energy dissipators. New York: McGraw Hill.
Escarameia, M. 2007. “Investigating hydraulic removal of air from water pipelines.” In Vol. 160 of Proc., Institution of Civil Engineers-Water Management, 25–34. London: ICE Publishing.
Falvey, H. T. 1980. Air-water flow in hydraulic structures: Engineering monograph 41. Denver: US Dept. of the Interior, Water and Power Resources Service.
Fuhrhop, H., H. E. Schulz, and H. Wittenberg. 2014. “Solution for spillway chute aeration through bottom aerators.” Int. J. Comp. Meth. Exp. Meas. 2 (3): 298–312. https://doi.org/10.2495/CMEM-V2-N3-298-312.
Hager, W. H. 1992. “Energy dissipators and hydraulic jump.” In Vol. 8 of Water science and technology library. Dordrecht, Netherlands: Kluwer Academic Publishers.
Hager, W. H., R. Bremen, and N. Kawagoshi. 1990. “Classical hydraulic jump: Length of the roller.” J. Hydraul. Res. 28 (5): 591–608. https://doi.org/10.1080/00221689009499048.
Hamam, M. A., and J. A. McCorquodale. 1982. “Transient conditions in the transition from gravity to surcharged sewer flow.” Can. J. Civ. Eng. 9 (2): 189–196. https://doi.org/10.1139/l82-022.
Hou, Q., A. S. Tijsseling, J. Laanearu, I. Annus, T. Koppel, A. Bergant, S. Vuckovic, A. Anderson, and J. M. C. van’t Westende. 2014. “Experimental investigation on rapid filling of a large-scale pipeline.” J. Hydraul. Eng. 140 (11): 04014053. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000914.
Jain, S. C. 1988. “Air transport in vortex-flow drop shafts.” J. Hydraul. Eng. 114 (12): 1485–1497. https://doi.org/10.1061/(ASCE)0733-9429(1988)114:12(1485).
Kabiri Samani, A. B., M. Borgheie, and M. H. Saeidi. 2006. “Experimental results of pressure fluctuations in a water conduit section due to formation of unstable two-phase air-water flow.” J. Comput. Methods Eng. 24 (2): 69–86.
Kalinske, A. A., and J. M. Robertson. 1943. “Closed conduit flow.” Trans. Am. Soc. Civ. Eng. 108: 1435–1447.
Kent, J. C. 1952. The entrainment of air by water flowing in circular conduits with downgrade slope. Berkeley, CA: Univ. of California.
Lauchlan, C. S., M. Escarameia, R. W. P. May, R. Burrows, and C. Gahan. 2005. Air in pipelines: A literature review. Wallingford, UK: HR Wallingford.
Lowe, N. J., R. H. Hotchkiss, and E. J. Nelson. 2011. “Theoretical determination of sequent depths in closed conduits.” J. Irrig. Drain. Eng. 137 (12): 801–810. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000349.
Montes, S. 1998. Hydraulics of open-channel flow. Reston, VA: ASCE.
Mortensen, J. D., S. L. Barfuss, and M. C. Johnson. 2011. “Scale effects of air entrained by hydraulic jumps within closed conduits.” J. Hydraul. Res. 49 (1): 90–95. https://doi.org/10.1080/00221686.2010.536695.
Patrick, A. C. 2015. “Air entrainment and acoustic wave celerities following a rapidly moving pipe filling bore.” M.S. thesis, Dept. of Civil Engineering, Auburn Univ.
Pothof, I. W. M. 2011. “Co-current air-water flow in downward sloping pipes.” Ph.D. dissertation, Dept. of Sanitary Engineering, Technical Univ. of Delft.
Pothof, I. W. M., and F. Clemens. 2010. “On elongated air pockets in downward sloping pipes.” J. Hydraul. Res. 48 (4): 499–503. https://doi.org/10.1080/00221686.2010.491651.
Pozos, O., C. A. Gonzales, J. Giesecke, W. Marx, and E. A. Rodal. 2010. “Air entrapped in gravity pipeline systems.” J. Hydraul. Res. 48 (3): 338–347. https://doi.org/10.1080/00221686.2010.481839.
Qian, Y., D. Z. Zhu, W. Zhang, N. Rajaratnam, S. Edwini-Bonsu, and P. Steffler. 2017. “Air movement induced by water flow with a hydraulic jump in changing slope pipes.” J. Hydraul. Eng. 143 (4): 04016092. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001252.
Rabben, S. L., H. Els, and G. Rouve. 1983. “Investigations on flow aeration at offsets downstream of high-head control structures.” In Vol. 4 of Proc., 20th IAHR Congress, 354–360. USSR: Moscow.
Rajaratnam, N. 1967. “Hydraulic jumps.” In Vol. 4 of Advances in hydroscience, edited by V. T. Chow, 197–280. New York: Academic Press.
Schulz, H. E., J. D. Nóbrega, A. L. A. Simões, H. Schulz, and R. M. Porto. 2015. “Details of hydraulic jumps for design criteria of hydraulic structures.” Chap. 4 in Hydrodynamics: Concepts and experiments, edited by H. E. Schulz, 73–116. London: IntechOpen.
Sharma, H. R. 1976. “Air-entrainment in high head gated conduits.” J. Hydrol. Div. 102 (11): 1629–1646.
Stahl, H., and W. H. Hager. 1999. “Hydraulic jump in circular pipes.” Can. J. Civ. Eng. 26 (3): 368–373. https://doi.org/10.1139/l98-068.
USACE. 1980. Engineering and design: Hydraulic design of reservoir outlet works. Washington, DC: USACE.
Vasconcelos, J. G., and S. G. Wright. 2006. “Mechanisms for air pocket entrapment in stormwater storage tunnels.” In Proc., 2006 ASCE EWRI World Environmental and Water Resource Congress. Reston, VA: ASCE.
Vischer, D. L., and W. H. Hager. 1995. “Energy dissipaters.” In IAHR hydraulic structures design manuals 9. New York: Taylor & Francis.
Wisner, P. E., F. N. Mohsen, and N. Kouwen. 1975. “Removal of air from water lines by hydraulic means.” J. Hydraul. Div. 101 (HY2): 243–257.
Zhou, F., F. E. Hicks, and P. M. Steffler. 2002. “Observations of air-water interaction in a rapidly filling horizontal pipe.” J. Hydraul. Eng. 128 (6): 635–639. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:6(635).
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©2019 American Society of Civil Engineers.
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Received: Dec 13, 2018
Accepted: Jun 12, 2019
Published online: Nov 28, 2019
Published in print: Feb 1, 2020
Discussion open until: Apr 28, 2020
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