LAUSR

In this study, the fluid hammer of viscoelastic flow in pipes is studied numerically. Here, the Oldroyd-B model is used as the constitutive equation. This model is suitable for dilute viscoelastic solutions and Boger liquids. The numerical solution is obtained using a two-step variant of the Lax–Friedrichs (LxF) method. The derived equations are non-dimensionalized, and the effect of Deborah and Reynolds numbers and the viscosity ratio on the behavior of viscoelastic flow during fluid hammer caused by the sudden closure of a downstream valve in a reservoir-pipe-valve system is investigated in detail. Present results show that the attenuation of the laminar fluid transient is affected by viscoelastic properties of the non-Newtonian fluid. Moreover, the results indicate that the shear stress in viscoelastic fluid hammer phenomena is significantly lower than those in Newtonian fluid with similar viscosity.