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Analysis of PVC Pipe-Wall Viscoelasticity during Water Hammer |
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| Authors: | Alexandre Kepler Soares Dídia I C Covas Luisa Fernanda R Reis |
| Affiliation: | 1Postdoctoral Fellow, Dept. of Hydraulic and Sanitary Engineering, S?o Carlos School of Engineering, Univ. of S?o Paulo, Sao Carlos, SP, Brazil; presently, Civil Engineering Dept., Instituto Superior Técnico, Technical Univ. of Lisbon (TULisbon), Ave. Rovisco Pais, 1049-001 Lisbon, Portugal (corresponding author). E-mail: aksoares@gmail.com 2Assistant Professor, Civil Engineering Dept., Instituto Superior Técnico, Technical Univ. of Lisbon (TULisbon), Ave. Rovisco Pais, 1049-001 Lisbon, Portugal. E-mail: didia.covas@civil.ist.utl.pt 3Professor, Dept. of Hydraulic and Sanitary Engineering, S?o Carlos School of Engineering, Univ. of S?o Paulo, C.P. 359, 13566-590 S?o Carlos, SP, Brazil. E-mail: fernanda@sc.usp.br |
| Abstract: | This research work focuses on the analysis of hydraulic transients in polyvinyl chloride (PVC) pipes, which are characterized by a viscoelastic rheological behavior. Transient pressure data were collected in a pipe rig consisting of a set of PVC pipes. The creep function of the PVC pipes was determined by using an inverse transient model based on collected transient pressure data and compared with that obtained by carrying out mechanical tensile tests of PVC pipe specimens. The numerical results obtained from the transient solver have shown that the attenuation, dispersion, and shape of transient pressures were well described. The incorporation of the viscoelastic mechanical behavior in the hydraulic transient model has provided an excellent fitting between numerical results and observed data. Calibrated creep function based on inverse analysis fit the one determined by mechanical tests well, which emphasized the importance of pipe-wall viscoelasticity in hydraulic transients in PVC pipes. |
| Keywords: | Hydraulic transients Viscoelasticity Pipe networks Polyvinyl chloride Water hammer |