# Verification of the Herschel-Bulkley Model by a Visualization Experiment of a Elastoviscoplastic Yield-Stress Fluid Flow in Straight and Bended Tubes

## TL;DR

This study experimentally visualizes elastoviscoplastic yield-stress fluid flows in straight and bended tubes to verify the Herschel-Bulkley model, highlighting the importance of yield stress, viscosity, and viscoelasticity in flow predictions.

## Contribution

The paper provides experimental validation of the Herschel-Bulkley model for yield-stress fluids in complex tube geometries, emphasizing the need to consider viscoelastic effects for accurate modeling.

## Key findings

- Experimental visualization confirms Herschel-Bulkley model predictions.
- Flow behavior is significantly affected by yield stress, viscosity, and viscoelasticity.
- Enhanced models are needed for accurate flow prediction in bended tubes.

## Abstract

The elastoviscoplastic yield-stress fluid flows in a horizontal straight tube and a bended tube have been investigated using hydrogen bubble visualization method. The experimental results are used to verify the empirical Herschel-Bulkley model. Both experimental and theoretical investigations well predict the yield-stress fluid flow behaviors. It is found that the significant factors influencing on the predictions of the Herschel-Bulkley model are the yield stress, viscosity and viscoelasticity. For the yield-stress flows in the bended tube, a more delicate constitutive model with consideration of the viscoelastic effects is expected for accurately predicting the flow behaviors.

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Source: https://tomesphere.com/paper/1903.10888