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A mighty wind
Research project will create tornado in Howe Hall.
- As big as Howe Hall is on the Iowa State campus, it seems amazing that
a new research project involving Bill Gallus, associate professor of geological
and atmospheric sciences, will create a tornado in the building that will
rise to four feet in diameter with winds of 60 mph.
"This will be the biggest vortex in a wind tunnel anywhere," Gallus
says. "I'm really excited to see a man-made vortex of that scale and
see what data we can collect from it."
Gallus and two faculty members in the College of Engineering’s Department
of Aerospace Engineering (Partha Sarkar and Fred Haan) are collaborating
on the project. The trio will design and build a simulator that will create
moving tornados.
Their ultimate goal is to learn how to construct homes and other buildings
or structures that better withstand the wrath of a tornado.
"At the minimum we hope to find out what exact forces and pressures
are placed on a structure by high wind," Gallus said. "Hopefully
with our findings we’ll be able to actually change how construction
firms build structures."
Gallus is in charge of collecting full-scale wind speed data and numerically
simulating the wind flow near the ground.
"We are basically trying to build the first tornado wind simulator
ever that has a 'translating tornado,'" Gallus said.
A translating tornado is one that moves in a path similar to a real tornado.
Gallus says tornado simulators typically use a stationary vortex. The researchers
believe that the wind loads on buildings struck by a moving, or translating,
tornado may be significantly higher than those measured in traditional wind
tunnel experiments.
That's the engineering component of the study.
What Gallus is particularly interested in is the wind speed data near the
ground.
"The first goal has an entirely engineering focus to it," he said.
"I'm also going to investigate why two storms look exactly the same
and one will produce a tornado and one won't."
The temperature and air currents may hold the key to determining why tornados
are formed sometimes and sometimes not. If Gallus can determine that key
issue, then weather forecasters will be able to better warn individuals
in the path of such a storm.
"The simulator should directly help improve the safety of the general
public," Gallus said.
The simulator is being built in Howe Hall through a three-year, $300,000
National Science Foundation grant. The research team also received a Faculty
Development Grant from the College of Liberal Arts and Sciences to begin
the project.
In addition to the data from the simulator, the team will be using data
collected by "Doppler on Wheels" radars, which will help them
get an accurate idea of the actual wind velocity near the ground during
a tornado for the purpose of evaluating the laboratory simulator.
"We hope to compare the real data from the near-ground-level Doppler
with computer model data and the data we create from the Howe Hall simulator,"
Gallus said. "This will hopefully verify the results we are getting
from the simulator to show that it is producing something that is happening
in the real world."
Gallus feels that the Howe Hall simulator data will provide a more accurate
reading of what happens at the ground level of a tornado than anything else
available.
Around LAS
October 6-19, 2003
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