Read full obituary in the News-Gazette.
After completing his PhD in mechanical engineering at the University of Illinois in 1963, Addy joined the Department of Mechanical and Industrial Engineering as an assistant professor. He was promoted to associate professor in 1967 and to professor in 1973.
Addy served as Department Head from 1987 to 1998. His vision of a state-of-the-art teaching and research facility resulted in the multimillion dollar renovation and remodeling of Mechanical Engineering Laboratory. With state and federal support for the department on the wane, he also focused on developing the department’s base of private funding. By the time he retired, the department had five professorships in place. His wife, Sandra, helped to secure and further many of the accomplishments he made in the advancement of the department.
Internationally renowned for his research in the areas of gas dynamics in high-speed flows, ejectors and nozzles, separated and base flow problems, and fluid dynamic characteristics of valves, Addy was honored with four lectureships from the Advisory Group for Aeronautical Research and Development of NATO, was a two-time visiting research professor for the U.S. Department of the Army and was also a visiting research professor for the U.S. Army Missile Laboratory. In 1983, he received the Outstanding Research Accomplishment Award from the U.S. Army Research Office. He is a Fellow of the American Society for Engineering Education, which awarded him its Ralph Coats Roe Award in 1990, and of the American Society of Mechanical Engineers, which named him an Honorary Member in 2006 in recognition of “a lifetime of internationally distinguished research in fluid dynamics and national advocacy of quality and innovation in engineering education; and for more than two decades of superb leadership of a nationally recognized academic department.” He is also an Associate Fellow of the American Institute of Aeronautics and Astronautics.
A pioneer of fluid mechanics, Addy attributed his education at Illinois as what motivated him to conduct research on ejectors and separated flows.
He began this research while a graduate student in the Department of Mechanical Science and Engineering, formerly known as the Department of Mechanical and Industrial Engineering. After earning his PhD, he joined the faculty and continued researching innovative theoretical flow models. These models were the first departure from piecewise one-dimensional analysis to an integrated two-dimensional interaction model with viscous mixing. They established a foundation to the understanding of ejector theory and operation that has become a classic.
Addy also made lasting contributions to the areas of base drag and separated flow. He investigated specialized applications in missile and aircraft propulsion and fundamental contributions to the understanding of high-energy chemical laser performance. His research was so impressive that the U.S. Army Research Office and the U.S. Army Missile Command funded him and his colleagues continuously for more than 30 years.
His research models provided powerful estimates of the behavior of phenomena in high-speed compressible flows that had not been previously understood. Addy used this information to build computer programs that were widely used by military and civilian aircraft and missile propulsion systems designers during the 1960s to 1980s. Among the most notable programs his system was used for were the Concorde and the Space Shuttle.
In addition to being a successful researcher, he was also an award-winning faculty member at Illinois. His enthusiasm for teaching, support for interdisciplinary team projects, student societies, and general student concerns made him popular among undergraduates. In 1993, a college-wide committee of students selected him as an Honorary Knight of St. Patrick because of his support for undergraduate students.
During this time as Department Head, Addy had a profound impact on the department’s direction by paying close attention to the quality of education provided, research conducted, and public service completed. During his tenure, the department was consistently ranked among the best in the nation.
The support he gave to faculty, as well as the strong ties he built with private industry helped him aggressively pursue resources and national recognition for the department, which increased faculty potential and accomplishments. He also recognized the importance of philanthropic support. Currently, 15 of the department’s faculty members hold professorships that are due in large part to his fundraising efforts.
In 2006, he was named an Honorary Member of the American Society of Mechanical Engineers (ASME), the society’s highest honor. He is also a Fellow of the American Society for Engineering Education (ASEE).
He was named as one of the College of Engineering’s Distinguished Alumni in 2017.