Smits wins science awards

Mechanical and aerospace engineering professor Alexander Smits, a 25-year veteran of the University and a former chair of his department, has been chosen to receive two major awards for his extensive work in the field of fluid mechanics.

The first honor, the 2007 Pendray Aerospace Literature Award, acknowledges his contribution to aerospace literature while the second, the 2007 Fluids Engineering Award from the American Society of Mechanical Engineers, recognizes his extensive research.

Smits' research has focused on determining the basic laws governing turbulence in fluids.

"We live in a turbulent system, the atmosphere," Smits said. "We understand fairly well what happens in a simple system, like a pipe. But for something more complex, like a ship in water, we can't predict how it will behave."

By performing experiments to measure turbulence in controlled systems, he hopes to understand the basic rules of turbulence, enabling better fluid-flow simulation programs and more efficient designs for ships and aircraft. As it stands, "Ninety percent of the energy used by a cruising ship is lost by turbulence," he said.

Smits' latest experiments attempt to create high Reynolds number turbulence, a measure of the complexity of turbulence in a system. A slow-flowing liquid in a small tube under laboratory conditions will have a relatively simple turbulence pattern and therefore a low Reynolds number.

In a more complicated system, such as the eddies caused by a submarine, the flows are more complex and have a high Reynolds number. High Reynolds number turbulence is harder to predict and simulate but is frequently encountered in real-life systems.

To study high Reynolds number turbulence in a lab, Smits conducts experiments at the Forrestal Campus on the flow of highly compressed air.

At about 200 atmospheres, air has a quarter of the density of water and creates complex turbulence without the use of the extremely large apparatus needed for a comparable study under atmospheric pressure.

He is also in the process of completing a wind tunnel on the Forrestal campus, which will allow him to "do the kind of [basic] research that it's very hard to do anywhere else." Though many wind tunnels exist in the United States, most of them are dedicated to optimizing a specific design — like an airplane wing — rather than basic research.

Included in the new wind tunnel will be a magnetic suspension system, which allows objects to be suspended without using physical supports that disturb airflow. Smits hopes to be one of the first scientists to study airflow around a suspended sphere.

"[Smits'] elegant experiments have greatly enriched our ability to understand and predict unsteady fluid motions," MAE department chair Philip Holmes said in an email. "We are delighted that his work has been recognized by the ASME Fluids Engineering Award and the AAAS Pendray Award."