Momentum Member Spotlight – April 2016

AIAA Congratulates Earl H. Dowell

By Duane Hyland, AIAA Communications

Using its short stint in Washington, DC, to recharge its batteries, this month the Spotlight felt it was up to some short travel and pointed its beam south of DC to fall on Durham, North Carolina, and the campus of Duke University, illuminating Earl H. Dowell, an AIAA Honorary Fellow, and William Holland Hall professor in the university’s Mechanical Engineering department.

Dowell is this year’s winner of the AIAA Reed Aeronautics Award. He will receive the award on 15 June during the AIAA Aerospace Spotlight Awards Gala at the Ronald Reagan Building and International Trade Center in Washington, DC The award honors Dowell’s “pioneering contributions to aeroelasticity, structural dynamics, and unsteady aerodynamics, which has an enormous influence on aerospace technology.”

Dowell’s work has focused on several areas of aerospace, including studying panel flutter – or how aircraft panels behave at speed; the problem of limit cycle behavior in various military aircraft at transonic speeds; and the performance of helicopter blades. All of his work has created a wide body of literature used by researchers across the aerospace community. Among his critical contributions were recognizing the nonlinear nature of panel flutter; improving computational fluid mechanics models, as well as computational structural dynamics models; and creating a substantial body of literature for researchers to draw on in the field of Reduced Order Modeling (ROM). Dowell was among the first to recognize the important role of geometric nonlinearities on the aeroelastic stability of helicopter rotor blades. He and his colleague, Dewey Hodges, developed basic equations describing rotor blade behavior that researchers use in the analysis of hingeless rotor blades in hover and forward flight. He is the editor and co-author of “A Modern Course in Aeroelasticity,” considered to be the leading text in the field.

Dowell’s numerous honors include the 2008 Guggenheim Medal; 2007 Walter J. and Angeline H. Crichlow Trust Prize; the 2007 American Society of Mechanical Engineers (ASME) Spirit of St. Louis Medal; the 2002 AIAA von Kármán Lectureship in Astronautics; and the 1980 AIAA Structures, Structural Dynamics and Materials Award. Dowell is an elected member of the National Academy of Engineering and an ASME Fellow.

When I asked Professor Dowell what his inspiration was to pursue aerospace as a career, he noted that his inspiration came from his childhood, stating: “Growing up in a small town of less than 2,000 inhabitants in Illinois, I fantasized from about the age of ten as to where an airplane could take me,” and, illustrating that the dreams of youth are often resilient, he concluded, “and I am still enjoying that fantasy, which has often turned to reality.”

Dowell had a long list of mentors and points of inspiration for his career, noting that it his Uncle Bill, a pilot and Air Force veteran, who first inspired him. Other mentors included “Harry Hilton, a professor at the University of Illinois who is still active as he is about to celebrate his 90th birthday”; AIAA Fellow John Dugundji, Dowell’s doctoral adviser at MIT; “along with committee members – Holt Ashley, Marten Landahl, and Herb Voss.” Dowell also pointed out that Voss was his first boss at The Boeing Company, and he cited Jon Turner, Voss’ boss as another influence. He also mentioned that “Court Perkins, our Department Chair at Princeton and later President of the National Academy of Engineering, was also a powerful and much appreciated mentor,” and added, “When I came to Duke it was Terry Sanford then our President, and former governor, and future senator.”

When asked what his favorite career memory was to this point, Dowell replied, “There are far too many to name, but being in charge of a major wind tunnel test program at the advanced age of 23 with much more experienced engineers on the team was a memorable experience. Some of those fellows were over 40!” He continued, remembering his “first faculty position at Princeton was exciting as I was the most junior member of an otherwise, all-star cast.” He continued, “joining Duke as the Dean of Engineering was a major challenge that worked out well.” He reflecting that “looking back on all these experiences I am not sure why I was brave or foolish enough to take them on.”

When it came to advice for students who are seeking a career in aerospace, Dowell reached back to his childhood and shared some things his mom taught him: “The very best career advice I have ever received was from my mom. She told me ‘always try to work with people who are a step ahead of you.’” Dowell noted his mom also “really did not think it would be all that hard for me to find them.”

For young professionals just starting out in aerospace, Dowell advised: “As a parent, I discovered that when it comes to advice, often less is more. All three of our children have been personally and professionally successful even though the oldest received much more advice than the youngest. It is hard to see the difference in their subsequent success. When it comes to offering advice and mentoring, timing is critical. You look for the learning moment.”

When I asked Professor Dowell what he felt the value of AIAA was to engineers and scientists, he responded, “AIAA and I have been together since my student days and the opportunity to learn from our heroes and peers has been exciting and very rewarding.” He shared this memory: “I still remember seeing Theodore von Kármán at an AIAA meeting – at that time it was IAS – and having the courage to say hello and his gracious reply.”

We closed our talk by discussing the future of aerospace, specifically what great advances in aerospace technology and/or science are on the horizon? Dowell replied, “In my own field of aeroelasticity substantial progress has been made in understanding – and exploiting on occasion – nonlinear phenomena.” Dowell continued, “Panel flutter was an early success, but freeplay induced flutter and limit cycle oscillations and even unsteady separated flows (buffet) are beginning to be modeled with some fidelity. The holy grail in my opinion is a rational nonlinear dynamics model of turbulence and I hope to be active long enough to see us well along that path,” humorously concluding “but I may have to stay healthy for several more years.”

AIAA congratulates Earl Dowell for his selection as the April 2016 Spotlight subject, and for winning this year’s AIAA Reed Aeronautics Award.