In this work the measurement setup of the TECH flow test setup is expanded with a laser to illuminate two-dimensional slices of the flow in the cavity. Results obtained from Shear Stress Transport...Show moreIn this work the measurement setup of the TECH flow test setup is expanded with a laser to illuminate two-dimensional slices of the flow in the cavity. Results obtained from Shear Stress Transport and Detached Eddy Simulation numerical simulation methods are then compared with laser measurements to determine whether the simulations are accurate, both quantitatively by comparing vortex positions and qualitatively by comparing phenomena that are observed. Finally, the Shear Stress Transport model is used to simulate flow for a number of nozzle designs that were designed to prevent arcing in the coaxial inlet.Show less
In this research project, we attempt to develop numerical simulation models to investigate surface acoustic waves (SAWs) and how they can be efficiently excited using interdigital transducers (IDTs...Show moreIn this research project, we attempt to develop numerical simulation models to investigate surface acoustic waves (SAWs) and how they can be efficiently excited using interdigital transducers (IDTs). These devices already find use in applications such as filtering devices for mobile communication systems. We identified the equation of motion in solids, Gauss’ law of electrostatics and the piezoelectric constitutive equations combined with material properties as the basic physics required to model IDTs. Based on these equations, we developed 2D and 3D finite element method (FEM) simulations in COMSOL, with lithium niobate and gallium arsenide as substrate materials, which we used to investigate the IDT frequency response. We also investigated the transient response of IDTs. Our results are in good agreement with analytic theory, which validates our model and approach. These models can now be used to optimize IDT device designs. Lastly, we propose and implement the first steps toward an optical setup based on a Michelson interferometer to detect surface acoustic waves.Show less
Dielectrophoresis is a widely used technique for on-chip manipulation of polarizable objects like cells, viruses and microparticles. Recently the use of nanotechnology enabled scaling down the...Show moreDielectrophoresis is a widely used technique for on-chip manipulation of polarizable objects like cells, viruses and microparticles. Recently the use of nanotechnology enabled scaling down the dielectrophoretic trapping to the level of nanoparticles and even single molecules. We aim to develop a dielectrophoresis-based tool to trap and actuate single biomolecules in order to study them. In this thesis we have designed and simulated a nanoscale dielectrophoretic trap as well as explored the possibilities of actuating trapped nanoparticles between the two hotspots of the trap. The simulation framework developed in this thesis based on COMSOL Multiphysics and python simulations paves the way to smart engineering of single-molecule dielectrophoretic traps, which can reduce the cost and time for production and development.Show less
