Document Type

Dissertation

Date of Award

12-31-2022

Degree Name

Doctor of Philosophy in Chemical Engineering - (Ph.D.)

Department

Chemical and Materials Engineering

First Advisor

Piero M. Armenante

Second Advisor

Ecevit Atalay Bilgili

Third Advisor

Murat Guvendiren

Fourth Advisor

Roman S. Voronov

Fifth Advisor

Andrei Potanin

Abstract

The discharge of non-Newtonian, complex fluids through orifices of industrial tanks, pipes, dispensers, or packaging containers is a ubiquitous but often problematic process because of the complex rheology of such fluids and the geometry of the containers. This, in turn, reduces the discharge rate and results in residual fluid left in the container, often referred to as heel. Heel formation is undesired in general, since it causes loss of valuable material, container fouling, and cross-contamination between batches. Heel may be of significant concern not only in industrial vessels but also in consumer packaging. Despite its relevance, the research in this area is significantly limited.

Previous research conducted in simpler systems, such as orifices of pipes and vessels, has already shown that the discharge of fluids through orifices is significantly affected by the geometric parameters and the fluid rheology. More specifically, the geometric properties of the orifice such as the diameter ratio, aspect ratio, and orifice shape, and the rheological properties of the fluid played a critical role on the discharge of complex fluids through orifices of vessels and pipes. However, how these parameters affect the discharge of complex fluids flow from more complicated systems such as consumer dispensing bottles operating with a hand pump has remained uninvestigated.

Therefore, the overall objectives of this work are to quantify the discharge hydrodynamics in dispensing bottles and the resulting heel for a wide range of geometries, operational parameters, and fluid rheology through the use of experimental and computational approaches. Particle Image Velocimetry (PIV) is the main experimental tool used in this work. A novel experimental methodology is also developed and utilized to optimize the transparency of the highly complex fluids such as pastes, for their optical hydrodynamic investigations using PIV. In addition, Computational Fluid Dynamics (CFD) is also utilized to predict the hydrodynamics and the residual heel volume. The simulation predictions are validated against the experimental data.

It is found that the heel volume and profile after the discharge is strongly related to the flow during the discharge, and both static and dynamic aspects of the discharge process can be determined using PIV, and predicted using CFD. Finally, correlations to predict the heel volume based on the rheological and geometric parameters are presented. It is expected that this work will be of significant academic and industrial interest, especially for product developers and packaging engineers to optimize the shape of dispensing bottles so that the discharge process from such containers is facilitated, and the heel volume is minimized.

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