A Hurricane on Wheels

Researchers at the University of Florida (UF) have developed a portable wind and rain simulator that can create a hurricane environment in a laboratory setting for scientific study. The unique device, reaching wind speeds equivalent to those of Hurricane Katrina, is equipped with eight industrial fans powered by four marine diesel engines. The simulator is mounted on a trailer and will be used on vacant homes to test building products, urban landscapes, and anything else that might be affected during a storm.

“This device will really help us be able to better understand storm-related problems [with building construction] and is certainly important for the rapid advancement of technology to become more hurricane resistant,” says Rick Dixon, the executive director of the Florida Building Commission.

Since the late 1990s, UF has been leading a program called the Florida Coastal Monitoring Program, a consortium of schools that has been deploying portable towers in the path of land-falling hurricanes to take turbulence measurements. The UF researchers have used this data as a basis for building the simulator to replicate what they have observed. “The portable wind simulator is an apparatus that can produce sufficient wind and wind-driven rain at a large scale to damage full-size structures, and that allows us to conduct experiments where we look at what worked and what didn’t work,” says Forrest Masters, an assistant professor of civil and coastal engineering and leader of the hurricane-simulator project.

The simulator is outfitted with eight five-foot-tall industrial fans, each weighing approximately 1,200 pounds and stacked in two rows. The fans will be powered by four 700-horsepower marine diesel engines, a type of boat engine. The transfer of power from the engines to the fans is controlled by an innovative hydraulic drive system designed by Linde Hydraulics Corporation and Cunningham Fluid Power. Once the engines are redlined, they turn a set of hydraulic pumps that drive fluid through the motors housed in the fans, which spins the fans, explains Masters.

The wind from the fans will pass through a custom-built duct that enables it to accelerate to the desired speed. At the end of the duct are rudders that allow the researchers to direct the wind. Inside the rudders is a water-injection system to simulate wind-driven rain.

“The wind flow that comes out of such a device should be one that reproduces reasonably well the features of real atmospheric flows generated by hurricanes,” says Emil Simiu, a research professor at the International Hurricane Research Center, at Florida International University (FIU). Simiu is working on a similar device, called the Wall of Winds, with a team at FIU. Unlike Masters’s device, the Wall of Winds is stationary, so all tests must be conducted in the steel fabricated building on the FIU campus where the simulator is housed. The group, led by Arindam Gan Chowdhury, an assistant professor of civil and environmental engineering at FIU and director of the wind-engineering lab at the International Hurricane Research Center, just received $2 million from the state to enhance the six-fan design of the simulator.

Masters’s simulator will begin testing on vacant homes donated by the state in the next few weeks. He and his colleagues will be looking at the effects of hurricanes on certain corners and edges where a building’s walls come together and at how to keep cladding on roofs, windows, and doors to prevent water intrusion. The group will also be testing road signage, utilities, and infrastructure systems used in typical hurricane preparations. According to Dixon, the group’s work will directly translate into new building standards and code for 2007.

“In addition to uncovering the science behind … hurricane winds, I am looking forward to bringing industry together to look at these problems,” says Masters.