Exact Solution for Viscoelastic Flow in Pipe and Experimental Validation.

Area of Science:

• Rheology and Fluid Dynamics
• Computational Mechanics
• Polymer Physics

Background:

• Analytical solutions for viscoelastic fluid flows are challenging to develop.
• Existing methods often rely on specific rheological models like Giesekus or Phan-Tien-Tanner.
• The eXtended Pom-Pom model is a significant advancement in describing complex fluid behavior.

Purpose of the Study:

• To propose a novel parametric method for analyzing viscoelastic fluid flows.
• To provide solutions without requiring additional assumptions for rheological models.
• To validate the proposed method and compare different rheological models against experimental data.

Main Methods:

• A parametric representation of unknown velocity and stress tensor components was employed.
• The method allows for solutions without additional assumptions on the fluid's state equations.
• Experimental flow visualization using smoke image velocimetry (SIV) was conducted for validation.

Main Results:

• The proposed parametric method successfully yields solutions for viscoelastic fluid flows.
• Experimental data obtained via SIV were used to assess the accuracy of rheological models.
• The eXtended Pom-Pom model demonstrated superior predictive capability compared to the Giesekus model.

Conclusions:

• The developed parametric method offers a versatile approach to solving viscoelastic flow problems.
• The eXtended Pom-Pom model provides a more accurate description of the studied viscoelastic flows than the Giesekus model.
• Experimental validation confirms the effectiveness of rheological models in predicting complex fluid behavior.