Structured fluidization: Oscillatory gas-solid bubble flows.

Gas-solid fluidized beds are widely used in industry as an effective way to put in contact gases and powders. Their design however is not a reliable because the interaction between the air and the particle phase renders a rather unpredictable hydodynamics. In recent times, advanced designs have looked into the application off external forces to introduce some degree of structure into an otherwise chaotic system. Among other so-called assisted methods, the use of vibration or pulsating flows is a common way to enhance the performance of bubbling fluidized beds. The use of a oscillating or pulsating gas flow in particular can be used to create a coherent and sometimes a responsive flow structure. The use of oscillations causes the powder to compress and dilate intermittently, behaving in turns as a fluid or an elastic solid. Under certain conditions, this results in sections of the powder bed becoming compressed and channeling the gas forming bubbles in a very precise and predictable way. This turn a seemly chaotic bubbling process into a very ordered systems where bubbles are perfectly aligned into a specific pattern. The way solids mix and contact the gas in such a "dynamically structured bed" (https://www.sciencedirect.com/science/article/abs/pii/S025527012030605X) presents definitive advantage suggesting this phenomenon can be engineered into a completely new type of operation. In this project, we will study the creation of a stable structure bubble flow in a fluidized bed using computational fluid dynamics CFD and potentially Discrete Element Methods to look at the way in which a bubble pattern emerges in every flow oscillation, and how it propagates into a macroscopic flow structure.

Other Comments: 

Student requirements:
- A quality-oriented mentality and good mathematics .
- Genuine interest in modelling multiphase flows.
- Programming expertise with Python, Fortran or C++ (OpenFOAM), or the ability to quickly develop it.

Supervisor name: 
Dr Victor Francia
Supervisor and Deputy email addresses: 
v.francia@hw.ac.uk; a.ozel@hw.ac.uk
Deputy name: 
Dr Ali Ozel