Do you find geometry intriguing? Do you find flow fascinating? Have you ever travelled on a train moving so fast that you wondered why it didn't simply break up?
If the answer to any of these questions is yes, then this PhD in Modelling High-speed Bubble Trains could be for you.
Information In recent years, lab-on-a-chip microfluidic technology has revolutionised many fields: biology, medicine, analytical chemistry and also printing processes. However bottlenecks remain for improving the technology even further. One issue is that many microfluidic flows involve multiphase fluids, in which bubbles (or analogously droplets) are present: multiphase fluids are inherently more complex than single phase ones. A second issue is that the technology is continually seeking to increase throughput by increasing flow speed along a microfluidic channel: as the throughput increases however, so does the viscous drag between the flow and the channel wall, and that drag can tend to deform the bubble shapes.
Taken together, these two issues lead to a third one. In a slow multiphase flow, bubbles can be organised in a very particular geometric fashion, e.g. with bubbles arranged into a regular train. As the flow speed increases though, there is a risk that viscous drag might disrupt that regular geometry so much that it causes the train to fall apart.
The aim of the present PhD project is to develop models for bubble flows along channels, and then to deploy those models to design bubble trains that can retain their geometric structure despite high-speed flow. By manipulating the bubble size relative to channel size and also manipulating the number of bubbles in a train, it is expected that we will identify structures which are stable against the effects of viscous drag. These then will be candidate structures to use in high-throughput microfluidic devices in the future.
Research questions to be addressed include:
How is a given bubble train predicted to reconfigure as flow speed is increased?
What geometric properties of a bubble train allow it to survive high speed flow along a channel?
How does varying the number of bubbles in a train influence the train's ability to survive high speed flow?
As a PhD candidate you will contribute to the research programme of the Department of Mechanical Engineering at TU Eindhoven, in which there is considerable expertise on flow and microsystems.
In order to address the project aim and research questions, in your role you will:
- develop models on the bubble scale for bubble trains flowing in channels.
- implement the models in a computer simulation program.
- analyse simulation results.
- prepare manuscripts for publication in the scientific literature.
- prepare presentations for scientific conferences.
- report to and interact with the supervisory team.
- interact with external collaborators.
TU Eindhoven values diversity and inclusivity within research teams, so we encourage candidates of all backgrounds to apply.