Investigation of viscoelastic effects on transient flow in a relatively long PE100 pipe

In this paper, the dynamic effect of the viscoelastic behavior of PE100 material, on the transient flow in a relatively long pipe, has been studied. At first, to study the transient flow in pipes with fluid structure interaction (FSI), two mathematical models, i.e., fully coupled four equation model and simplified two equation model, have been developed. The method of characteristics has been used to solve the model. Then, we have demonstrated that the viscoelastic behavior of PE100 plays a primordial role in the damping of the water hammer phenomenon. It has a dynamic effect to cause the decrease of pressure wave velocity with increase of pressure along the wave front. At the end of the paper, It has been shown that the coupled model with FSI does not introduce many changes from the simplified viscoelastic model.