Wavy-shaped buildings could cut hurricane wind damage by 60%

As Hurricane Isaias churned toward the Gulf Coast, many homeowners were thinking about their roofs. Hurricane-force winds and flooding cost U.S. households about $34 billion every year, according to the Congressional Budget Office. Reinforced construction and rounded corners can help, but engineers at Florida A&M University and Florida State University think a simpler, cheaper solution might come from the ocean's own curves.

The study

In a paper published in the journal Engineering Structures, the team built 3D-printed models of low-rise buildings with wavy walls and roofs. They tested three versions with wave amplitudes of 5 percent, 7.5 percent and 10 percent of the building's overall height. A 20-foot-tall building with a 10 percent amplitude would have waves extending about 2 feet. Then they put the models in a wind tunnel and measured wind pressure as air hit from different angles.

All the wavy models handled wind better than a flat version. The model with the deepest waves reduced peak wind pressure near roof and wall corners by 40 to 60 percent. Those corners and edges are where damaging forces usually concentrate.

How it works

Wind flowing over a flat roof separates at the leading edge and forms a single large vortex. That creates low pressure above the roof while higher pressure below pushes outward, producing a suction effect that can peel roofs off. Over a wavy surface, the wind skips along like a stone across a lake, forming a series of smaller swirls instead of one big one. That disruption prevents strong suction pockets from forming.

Pedro Fernández-Cabán, a civil engineer at Florida State University and a study co-author, said in a statement: "Changing a building's shape can significantly reduce the intensity of wind forces it has to withstand."

What's next

The researchers caution that the study looked only at wind pressure on model surfaces. They are now running additional experiments to understand how wind flows around the wavy structures and will use computer modeling to fine-tune the wave patterns and test other shapes. If the results hold up, wavy walls and roofs could become an attractive, simple option for architects and engineers in storm-prone areas.

• Engineering Structures
• Florida A&M University
• Florida State University
• hurricanes
• Pedro Fernández-Cabán
• wind damage