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The PhD defence will be in Abels utsikt - Niels Henrik Abels hus. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.
Ex auditorio questions: the chair of the defence will invite the audience to ask questions ex auditorio at the end of the defence.
- Submit request to access (available from 15th of November 1:15 pm until 29th of November 1:15 pm)
Trial lecture
29th of November, time: 10:15 am, room 1259 (Abels utsikt).
The fluid dynamics of swimming fish and technology solutions inspired by it
Main research findings
Internal waves are a phenomenon that occurs in stratified oceans. These waves play a vital role in the oceanic ecosystem, e.g., influencing the distribution of nutrients. I have conducted high-resolution simulations of internal solitary waves of depression as part of my thesis to gain further insight into the physical mechanisms these waves govern.
I have numerically recreated a well-known laboratory experiment of internal waves to obtain the behavior concerning instability in the bottom boundary layer beneath the wave. During the study, I have established a threshold criterion regarding instability in the bottom boundary layer. I obtained good agreement with laboratory experiments for the transition to instability, where long-standing computational attempts have been unsuccessful. The instability occurs much earlier for waves of considerably smaller amplitude than previously predicted. In the presence of vortices in the bottom boundary layer, Lagrangian tracer particles were seeded, and traced, to represent sediment motion.
A different part of this thesis involves analyzing data obtained by a new method for measuring the two-dimensional water flow in the field near ice.
The new method uses air bubbles as tracers to capture water velocity and has been validated in the laboratory with good agreement with analytical solutions.
Adjudication committee
- Reader Magda Carr, Newcastle University
- Professor Simen Ådnøy Ellingsen, Norwegian University of Science and Technology
- Professor Andreas Carlson, University of Oslo
Supervisors
- Professor John Grue, University of Oslo
- Researcher Johannes Röhrs, Norwegian MET
Chair of defence
Head of Department Geir Dahl.
Host of the session
Professor Andreas Carlson, University of Oslo