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Thesis Topics:Tidal Physics
| Headland Secondary Flows
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ADCP measurement and/or
modelling the structure of the Secondary Circulation
cells formed near the tip of a headland due to the
curvature of the flow. |
| Tidal Turbulence |
ADCP meaurement of the
horizontal structure of turbulence in a region where
flow separates from the shore. |
| Dynamical balance of
flow in Otago Harbour |
Flows of 2 knots are
often seen in the Otago Harbour channel where it
passes through the narrow gap between the Halfway
Islands. The rapid flow acceleration with the gap
results in a change in the dynamical balance of
the flow. This project will use a ADCP mounted on
the University's vessel to measure flows
along the channel, momentum balance and drag coefficient
of the flow. |
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Contact Ross
Vennell
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Thesis Topics:Power from Tidal Currents
| Depth effects on power production |
Underwater turbines can extract power from tidal flows along channels. This project looks at the effects that variation in water depth across the channel has on a channel's potential to produce power. |
| Tidal turbines in a boundary layer |
This project explores aspects of the influence the bottom frictional boundary layer and the resulting variation of velocity with depth has on power production. |
| Efficency of ducted turbines |
Tidal turbines in large turbine farms are effectively in ducts created by the channel walls and adjacent turbines. The ducting improves efficency. This project is to quantify their efficency in the rectangular duct created by the sea surface, sea bed and adjacent turbines. |
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Contact Ross
Vennell |
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Thesis Topics:Others
| Dynamics of vessels. |
Use GPS technology to understand acceleration
and performance in vessel ranging from rowing skiffs to
large ships. |
| Drag on Swimmers |
Use Otago's swimming flume facility to
better understand and measure drag and its various components
on human swimmers. |
| Current forces on large ships
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Large ships in confined harbour basins
can significantly distort tidal currents within the basin.
This distortion affects the current forces which act on
the ship. Knowledge of these forces is important in understanding
how to best use tugs to turn vessels over 200m long. This
project would be to make measurements around
a manoeuvring vessel at Port Otago and/or develop models
for the forces acting on the vessel. |
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Contact Ross
Vennell
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Thesis Topics:Sea Ice
| Refrozen cracks
(theoretical) |
When a crack forms
in sea ice it frequently fills with sea water which then
freezes in an environment which is quite different to
that of the host sheet. This project would involve the
development of a theoretical model for the refreezing
of a crack in sea ice. |
| Refrozen cracks
(experimental) |
Laboratory experiments
on the effects of crack width and refreezing time on the
mechanical and physical properties of the refrozen crack. |
| Brine movement
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Measurement and/or
theoretical modelling of brine motion within a single
brine pocket in sea ice. This problem is complicated by
the fact that the shape of the pocket may change in response
to the movement of the fluid. |
| Acoustic emission
studies |
Comparison of the
character of acoustic emission signals from a crack-free
sea ice sheet with one containing a refrozen crack. |
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Thesis Topics:Wave Sea Ice Interaction
| Mathematical modelling
of wave-ice interactions. |
Ocean waves penetrating
a region covered by sea ice, either in the form of pack
ice or a shore fast ice sheet, are changed by the ice;
they are attenuated and their angular distribution is
altered. The ice may also be changed by the waves, e.g.
it may be broken up or redistributed into a different
configuration. Mathematical models of these phenomena
have been under development for several years, supported
by experimental work in Antarctica. |
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