Fluid Rheology Effect on Wave Attenuation in an Elastic Pipe

Modeling of Polymeric Liquid Material Properties Effect on Pressure Transients in the Elastic Pipe

“…The following values of parameters, typical for water solutions of polymers, were chosen: θ and the pulse width, defined by 0 τ , were varied. It was supposed that the tube wall material is polypropylene (  -viscoelastic liquid described by the Oldroyd model [5] The data illustrate the effect of the relaxation spectrum on the pressure in the wave. For each moment of time 3 plots, corresponding to the integral rheological model ( 1), the Oldroyd model with one relaxation time [5], and the Newtonian pure viscous model with p η η = , are compared.…”

“…It was supposed that the tube wall material is polypropylene (  -viscoelastic liquid described by the Oldroyd model [5] The data illustrate the effect of the relaxation spectrum on the pressure in the wave. For each moment of time 3 plots, corresponding to the integral rheological model ( 1), the Oldroyd model with one relaxation time [5], and the Newtonian pure viscous model with p η η = , are compared. We can conclude that rheological description of the liquid has essential impact on the pulse form -the integral model, which gives the most detailed description of polymeric liquid behavior in dynamic conditions, yields intermediate values of pressure in the wave, as compared to the data obtained within Oldroyd and pure viscous models, respectively.…”

“…The model was developed within an ideal liquid approximation and was focused on the investigation of the impact of the tube wall inertia and viscoelasticity. Liquid viscoelasticity effect on a step pressure pulse propagation in an elastic tube with viscoelastic liquid, described by Oldroyd model with one relaxation and one retardation times, was studied in [5]. In the present paper, the approach developed in [5] is extended for a more realistic case when material behavior of liquid is characterized by a spectrum of relaxation times caused by essentially different mobility of the macromolecules structure elements.…”