Computational Scientist Consults on Engineering for National Security

January 8, 2008

By Colleen Kearney Rich

Rainald Löhner Photo by Nicolas Tan

As director of the Center for Computational Fluid Dynamics, Rainald Löhner conducts research, writes, teaches and mentors. But he sees his role as a consultant, particularly to those in government who are handling issues of national security, as the most important one he and his center can fulfill.

“We are available. We are right here. We can have a chat,” says Löhner, speaking of his group’s proximity to the nation’s capital. “So many contractors are trying to sell the government something. These people need impartial input, and as a university team we can provide this on an engineering level. The government is served by it.”

Most people come to Löhner and his colleagues when an unforeseen problem requiring a more profound understanding of physics needs to be solved. This could be anything from a new luxury car that makes an annoying sound to an expensive electronic system that has a glitch.

And the key to opening the door to this form of understanding and creative problem solving is computational fluid dynamics, a combination of mathematics, physics, engineering, computer science and visualization techniques.

Image courtesy of the Center for Computational Fluid Dynamics

There are cars on the road that Löhner and his team of 15 to 18 scientists have helped design, and there may be a torpedo and a few small spy planes, but he can't give out any details. Löhner says the products that result from their work that do make it into the hands of the general public have been sanitized. The actual analysis is usually highly confidential and is often carried out by personnel with security clearances at locations outside the university.

Over the past two decades, developments in the computational sciences have had a major effect on the mechanics of gathering and producing knowledge. Computational experiments are commonplace across all the sciences, existing alongside the more traditional means of experimentation and analysis.

In engineering, these so-called numerical wind- and water-tunnels revolutionized the design and analysis of products and processes. Computational science has become what Löhner calls “the third pillar” of the empirical sciences. Moreover, computational science may, in many fields, become the dominant form of knowledge acquisition.

Simply put, it is much easier to blow up a building using computer modeling than to blow it up in real life, and the virtual world allows a scientist to create blast after blast, learning more about the building and the blast itself. The same applies to the study of airplanes, ships, cars or even arterial stents.

“We are at the intersection of the sciences,” says Löhner, who is a mechanical engineer by training. As a result, his team is multidisciplinary and highly collaborative, comprising not just engineers, but also physicists, mathematicians, computer scientists and human factors psychologists.

“One of our unique differentiators is that we write everything from scratch. Everything is homegrown,” he says. “It makes certain things slower, but on the other hand, you have complete control and understanding. You can make changes and improvements very quickly, and you aren’t dependent on other people.”

Löhner is the author of more than 500 scientific papers and the textbook "Applied Computational Fluid Dynamics Techniques," which he revised last summer. He is also the principal author of the FEFLO CFD software suite used by academia, industry and government.

The software developed by his group has been used to carry out simulations of the explosions of the World Trade Center in 1993, the American Embassy in Nairobi and the Challenger Space Shuttle. It also has been used to simulate the inflation of airbags and blood flow in carotid, renal and cerebral arteries.

And the small spy planes? The cars on the street? Well, they do exist. Löhner has actually seen them. “One of the greatest things about being an engineer is when you actually get to see what you’ve helped design and build,” he says.

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