A Mighty Wind

By Jeff Kelly Lowenstein
A Mighty Wind
Photo: Michael Gross

On January 28, 1967, two days after one of the heaviest blizzards in Chicago history, 20-year-old Hassan Nagib met Engineering Professor Andrew Fejer for the first time.

Fresh off of work and study stints in multiple European countries, Nagib (MAE ’68, M.S. ’69, Ph.D. ’72) did not know that he was looking at the man who would become a towering influence in his career. Nor did the Cairo native know that he had entered the university where he would spend the next 40 years.

But Nagib did know that he was unsure if Chicago was a city where he wanted to stay.

“I remember looking out the window and saying, ‘Is this really a place where I want to live?’” recalls Nagib, John T. Rettaliata Distinguished Professor of Mechanical and Aerospace Engineering.

Urged repeatedly by Fejer to remain on campus, despite the infamous Chicago winters, Nagib has done just that—and IIT has reaped tremendous benefits from his decision. In addition to earning all of his degrees here, Nagib has had an extraordinarily productive career as a researcher, teacher, administrator, and facilities builder, and has made a substantial local and international impact.

“He has great passion for his work and sets exceptionally high standards for all of us in the university community,” says President Lew Collens. A key factor in Nagib’s decision to stay on for graduate studies at IIT was the freewheeling intellectual environment—cultivated by professors like Fejer and turbulence expert Mark V. Morkovin—where Nagib was allowed to pursue his own research and to play a significant role in building several of the university’s wind tunnels and the first world-class wind tunnel, the National Diagnostic Facility (NDF).

In addition to his work on the NDF, Nagib’s early work centered on hydrodynamic stability. But it is in the area of flow quality of wind tunnels that he has made his largest professional mark. Nagib explains that turbulence can be either a positive or a negative force, depending on the context, and he has focused on reducing areas of resistance.

The financial stakes are enormous.

For example, a 7 percent reduction in resistance on the body of an airplane would equal the fuel savings that would occur if all automobiles increased their gas mileage from five miles per gallon to 60 miles per gallon.

An important element in obtaining meaningful results is having a testing site with a sufficiently large Reynolds number. Named for Osborne Reynolds, the number is the ratio of intertial forces to viscous forces. Small Reynolds numbers indicate that a fluid’s viscosity is dominant. Large Reynolds numbers, however, mean that viscosity is minimal and intertial effects are ascendant.

During the 1980s, Nagib oversaw the construction of the larger NDF that would be an effective testing ground to make some of those advances. The tunnel contains several revolutionary design features, including the installation of a cooling system that did not add any new parts to the tunnel. The facility has become an intermediate testing ground that is larger than those in many universities, but smaller and less expensive to operate than tunnels at companies such as Boeing, Lockheed Martin, or Bell Helicopter.

Completed in 1992, the tunnel was funded primarily through a government grant of about $2 million. Now valued at close to $10 million, the facility has yielded multiple benefits for IIT. In addition to drawing scholars and graduate students from across the country, it has helped to boost undergraduate student recruitment. “They see the opportunity [and ask], ‘You mean, one day I could work here?’” Nagib says.

Nagib’s work also has resulted in academic programming that benefits students and distinguishes the university—namely, the Interprofessional Projects (IPRO) Program, a signature component of the undergraduate experience. “He’s the guy that drove the creation of IPRO, and did it with great passion, energy, and vigor,” Collens says.

A former dean and department chair, Nagib has taken pride simultaneously in helping to improve the caliber of students at IIT, serving as academic vice president (mid- to late 1990s) and becoming the founding director of IIT’s Fluid Dynamics Research Center, which the United States Department of Defense recognized in the 1980s as a Center of Excellence.

Perhaps foremost as a dedicated teacher, Nagib has helped to create a supportive climate at IIT in which students are unafraid to make mistakes while receiving opportunities to advance their budding careers. Nagib says he tells students not to be defensive about errors, but rather to admit them, accept them, show that they understand the mistake, and move on to the next part of the problem.

He also has tried to pass to his graduates the standard of knowledge that he received from Morkovin and Fejer. “When you start your Ph.D. work with me, I better know more about the subject than you do,” Nagib says. “But when you leave, you better know more about your subject than I.”

According to Candace Wark (MAE ’88), former doctoral student and a current colleague of Nagib, he allowed her a lot of independence during her doctoral work and provided travel funds that enabled her to present at scholarly conferences.

The reputation and facilities of the Fluid Dynamics Research Center that Nagib directed were the reasons why Wark joined the faculty after completing her doctorate.

And as a young faculty member, she continued to receive support from Nagib.

“He provided the tools and motivation for me to teach, secure funding, and publish so that I could become a successful faculty member,” says Wark, now associate dean of Armour College of Engineering.

The Constant Factor

Hassan Nagib is rapidly approaching the 40th anniversary of his first visit to IIT, but his passion for research, teaching, and tackling knotty issues remains undimmed.

He continues to travel widely, visiting more than a dozen countries during a recent three-month stint, and serves as co-adviser to students in some of the very same countries where he worked and studied in his youth. Last year he was elected as a fellow of the American Institute of Aeronautics and Astronautics, an honor bestowed upon the most respected individuals in the aerospace industry.

Nagib also co-directs an ambitious effort to answer an unresolved question. The answer—the universality of the von Kármán Constant—could have substantial consequences for all turbulent flows adjacent to surfaces. The constant value of the logarithmic wind profile in the surface layer, the von Kármán Constant has long been held to have a value of .40, plus or minus .01.

Because Nagib is not convinced, he is heading the Center for International Cooperation in Long Pipe Experiments, or CICLoPE, project in Bologna, Italy, to crack the problem.

Working with a team of scholars from Italy, Sweden, Switzerland, England, Germany, Australia, Japan, and the United States, Nagib will record detailed turbulence measurements in combination with computational efforts to provide a focus of activity for leading international researchers in the field of wall-bounded turbulent flows.

Occurring in long tunnels built during the period between World War I and II, his research could have industrial applications and facilitate confirmation of the von Kármán Constant’s validity.

The quest has scientific and personal dimensions for Nagib, who calls von Kármán his intellectual grandfather. One of Theodore von Kármán’s students at California Institute of Technology was the late Andrew Fejer. Fejer, in turn, mentored Nagib during his undergraduate and graduate career at IIT as well as during his years as a fledgling scholar.

Unearthing and proving the answer could take five years, Nagib says, while understanding and modeling the correct information could last another decade.

Nagib is confident that by that time he will have left the university. “I’ll be out of this business,” he says, smiling. “I’ll just watch the young guys do it.”

Jeff Kelly Lowenstein is a writer based in Evanston, Ill.