Modeling and simulating the behaviour of interfaces within multicomponent fluids
Mick Carrozza defended his PhD thesis at the Department of Mechanical Engineering on January 17th.
Many fluids around us consist of drops of one fluid or gas bubbles in another fluid. Think for example of oil drops in water or soapy water. These fluids and their properties are being used in all kinds of practical applications in food processing, consumer care products, pharmaceuticals, petrochemicals and materials processing. During his PhD research Mick Carrozza developed a computational model that describes and predicts the mechanical behavior of the interface in these kinds of fluids with multiple components. This knowledge can be used to develop multicomponent materials further and make use of their potential to the fullest.
The interface between multiple components sometimes has a major effect on the mechanical behavior of fluids. For a large part it governs the structure and the properties of the entire material. It’s important to gain insight in what is happening at the interface between the different components when the fluid is flowing or is influenced by different environmental conditions like temperature for example. That way, the influence of the interface on the shape and distribution of drops in their surrounding fluid can be understood and controlled.
The flow of a drop in another fluid
During his PhD research Mick Carrozza developed and validated a computational model that simulates the flow of a single drop in another fluid under application of shear and extensional flow. A combination of these flows is frequently present in industrial applications. For the input of his simulations, Mick Carrozza developed a theoretical model that describes how the interface between the drop and the other fluid deforms and sustains stress when the surrounding fluids are flowing and exchanging momentum with the interface. Then, the model was fit to experimental data from literature.
Influence on drop deformation
The interface behaves like an elastic solid when it is loaded under small stresses, and like a fluid at higher stresses in the model that Mick Carrozza made. He chose for a model with this kind of behavior because this is frequently observed in this way in everyday applications. The computational model predicts the influence of these kinds of mechanical properties of the interface on the drop deformation. A result of an extensive study with this model is that the drop wants to return faster to its original spherical shape when it sustains stress than without extra stresses within the interface. Another important result of the study is that the local stresses at the interface have to be measured instead of just looking at the drop shape to characterize the mechanical behavior of the interface.
Developing useful multicomponent materials
The results from the model are useful to be able to develop multicomponent materials in a way that the material gets the desired functions for its application. These multicomponent materials can be used for, among other, controlled drug release in the body, the recovery of fuels and other products from crude oil and developing high-performance materials for demanding technology applications.
Research School: EPL (777 plataforma Polymer Laboratories).
Title of PhD thesis: . Promotors: Prof. Patrick Anderson and Dr. Markus Hütter. Co-promotor: Dr. Martien Hulsen.