by Aaron
Hoover
The latest "hurricane machine" developed by engineering
professor Forrest Masters will be deployed first to troubleshoot
effective ways to deter wind-driven rain.
It's huge, deafening, and can muster a 130-mph wind capable of
tearing off roofs and knocking down walls. But University of
Florida engineers say they may first deploy a new 3,800-hp
hurricane simulator to solve a more subtle problem: how wind-driven
rain enters homes.
What engineers call "water intrusion" was a huge damage-producer
during the 2004 and 2005 Florida storms. Although soffits have been
identified as a leading cause, much remains uncertain about where
to cast blame when windblown rain soaks wood floors, collapses
ceilings, or damages drywall, says Forrest Masters, a UF assistant
professor of civil and coastal engineering and lead designer of the
new machine.
The machine, the world's most powerful such portable wind machine,
can pelt windows and other components, as well as entire
structures, with steady or intermittent bursts of wind and
raindrops, mimicking real hurricanes. That should give engineers
the chance to test walls, framing connections, windows, doors, and
soffits — both how they perform together on an actual house
and how they perform separately. "We have a water-intrusion issue,
and we need a systems approach to identify the origin and mechanism
of the intrusion," Masters explains.
This updated "hurrican machine" is the latest version of a growing
arsenal of more and more massive hurricane simulators being
produced by UF, Florida International University, and other
research universities in the U.S. and Canada. It has eight
5-foot-tall industrial fans powered by four marine diesel engines.
The engines get their cooling water from a 5,000-gallon water tank
aboard the machine's tow vehicle, a tank that is also the source of
the simulated rain. At full power, the fans produce winds of about
100 mph. A custom-built duct funnels the air, accelerating the wind
to 130 mph, speeds equivalent to a Category 3
hurricane.
The UF engineers first tested the machine shortly before hurricane
season began June 1. A few weeks later, Masters met with code
officials and representatives from major window companies and test
laboratories. He is now working with these representatives on a
research agenda for the machine.
The wind engineers will also put the machine to use in myriad other
investigations. One of the more surprising: how hurricane winds
affect trees. Kurt Gurley, a UF associate professor of civil and
coastal engineering, notes that the researchers plan to work with
horticultural scientists to learn more about pruning trees for
storm survivability. The goal goes beyond canopy protection, he
says.
"If you could create some pruning policy for various species of
tree that reduces how much wind they feel," he explains, "it would
perhaps be nice preventive medicine for keeping power lines up
longer." — Aaron Hoover