Research interests
A list of publications is available
separately.
Flow over orography
I am currently working as a Research Fellow within the Atmospheric
Dynamics group in the School of the Environment. My research, funded by
NERC through UWERN,
is investigating 'Flow Over Orography'. I am involved in a variety of
projects including a mixture numerical, theoretical and experimental
work. Some of my current interests include :-
Dynamics of flow in forest canopies.
The presence of a forest canopy on a hill can make a significant
difference to the flow in the boundary layer over the hill. This can
impact on important phenomena such as flow separation and drag. I have
been investigating this using numerical simulations and also through
linear analytic solutions of the boundary layer equations.
Profiles of the change in wind speed over a small forested hill. Both
numerical and theoretical results are shown. The reversed flow within
the canopy over the lee slope is shown.
Turbulence closure schemes for boundary layer flow.
There are a variety of turbulence closure schemes in wide (and not so
wide) use for boundary layer flows. I have worked on comparing
various first and second order schemes with wind tunnel measurements
in neutral and stratified flow to assess the schemes suitability in
modelling flow over a hill. I have also been invesigating the use of
second order closure schemes for flow over canopied hills. The
presence of flow separation in the canopy makes this a difficult problem.
PV generation in mountain valleys
Using numerical simulations I have been investigating the generation
of PV near the surface in mountain passes and it's subsequent
advection out of the boundary layer to form PV banners.
2-D numerical simulation of flow through a mountain pass showing
generation of PV at the valley sides. The solid lines are isotherms
and the dotted lines are contours of equal Bernoulli potential. This plot
was generated using blasvis.
Gravity currents
I studied for my PhD in the fluid dynamics
laboratory in DAMTP, University of Cambridge. The title of my
thesis was "Gravity currents on slopes". As I was partly sponsored by
the Health and Safety
Laboratories the motivation was to model the dispersion of dense
gases in the atmosphere. My work consisted of a mixture of laboratory
experiments, numerical simulations and theoretical modelling.
More recently I have continued my interests in this field looking at
simple models for the role of surface fluxes in cold pool evolution
using shallow water theory. Interesting analogies can be made with
sedimenting gravity currents.
A gravity current in the lab. This is an instantaneous release of
salty water into fresh water, on a slope.
This is a numerical simulation of a 2-D lock release gravity current.
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Andrew Ross <aross@env.leeds.ac.uk>
Last updated: 30 May 2004