Unsteady friction and visco-elasticity in pipe fluid transients

Huanfeng Duan, Mohamed Ghidaoui, Pedro J. Lee, Yeou Koung Tung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

140 Citations (Scopus)


The current waterhammer models coupled with friction models cannot adequately represent the pressure wave attenuation observed in real-world pipe systems, because the pressure wave damping is affected by additional effects not accounted for. One such effect is pipe visco-elasticity from the material behaviour of pipe-wall to be investigated herein. The numerical results indicate that the pressure head attenuation attributable to unsteady friction is comparable to the visco-elastic effect during the initial transient stage, while the visco-elastic effect becomes dominant both in terms of damping and phase shift at later stages. An analytical analysis shows that the visco-elastic effect is more critical if the visco-elastic retardation time is less than the wave travel time along the entire pipeline length. In addition, it is demonstrated that the visco-elastic term in waterhammer models is wrongly referred to in the literature as energy dissipation instead of energy transfer between fluid and pipe-wall by the work done by the pressure force.
Original languageEnglish
Pages (from-to)354-362
Number of pages9
JournalJournal of Hydraulic Research
Issue number3
Publication statusPublished - 1 Jun 2010
Externally publishedYes


  • 2D model
  • Energy analysis
  • fluid transients
  • Fourier transform
  • pipe system
  • unsteady friction
  • visco-elasticity

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Water Science and Technology


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