Modeling of transient flow in plastic pipes

Abstract

We present a numerical code for calculating transient flow in plastic pipes, especially in the polyethylene pipe, to analysis water hammer phenomena. The set partial differential equations to be solved is obtained using conservation laws and behavior for the fluid and the pipe wall, associated with constitutive equations of the two media, and relationships compatibility of interfaces on velocities and stresses. Coupling due to Poisson's ratio is also incorporated in this model. A global digital processing is achieved using the method of characteristics. The results obtained are in good agreement with those found in the literature. a E m m = ( ) / / 0 1 2 ρ : Celerity of sound in the pipe wall

Numerical Analysis of Transient Pressure Damping in Viscoelastic Pipes at Different Water Temperatures

“…Both friction and viscoelasticity have significant impacts on the calculation of the peak pressure damping of transient flows in viscoelastic pipes, especially at different water temperatures [ 2 ]. This is because the water temperature affects not only the fluid characteristics [ 3 ], such as the density and viscosity of the water, but also the range of linear viscoelasticity with respect to the viscoelastic pipes [ 4 , 5 , 6 ]. Therefore, it is necessary to investigate the influence of viscoelastic and frictional factors in the numerical simulation of the peak pressure damping of transient flows in viscoelastic pipes at different water temperatures.…”