Author(s): Huan-Feng Duan
Linked Author(s):
Keywords: No Keywords
Abstract: The factors affecting pressure wave propagation and damping in real-world pipe systems include wall shear under unsteady turbulent conditions, material behavior of the pipe by viscoelastic effect, and energy transformations by interaction between fluids and pipes. This paper investigates the relative importance of unsteady friction (UF) and viscoelasticity (VE) effects in pipe fluid transients and points out new interpretations to the viscoelastic term in waterhammer model. The investigation is carried out using a quasi-2D waterhammer model that incorporates both UF and VE effects. The results show that the contribution of the UF effect to the peak damping of pressure head is comparable to the VE effect during the initial transient stage while, as time increases, the VE effect becomes dominant both in terms of damping and phase shift. In addition, it is shown that the viscoelastic term is wrongly referred to in the literature as being energy dissipation when in actual fact it is the work done by the fluid on the pipe and vice-versa
Year: 2009