Professor Ephraim M. Sparrow (1928–2019)
Family, friends, and the thermal science community must say goodbye to a great friend. We report with sorrow the passing of Professor Ephraim Sparrow on August 1. “Eph” was an intellectual giant whose contributions to the field of heat transfer are undoubtedly well known to everyone reading this memoriam. The numbers of researchers he has touched and whose research he has influenced are nearly uncountable. Before we list and discuss his intellectual accomplishments, we wish to talk about Eph as a friend.
It is very likely that most readers have interacted with Eph in some way during his long and prolific career. We all have our own personal stories. Some of us met Eph early in his career, after he left the NACA Lewis Research Center in Cleveland and joined the faculty at the University of Minnesota in 1959. For others, the encounter was later, in the 1960s–1980s, when he was at the height of his scientific productivity, publishing papers at an unbelievable rate. Yet others among us met him in the 1990s–2000s when his scholarly interests had shifted to tackling challenging real-world problems. But regardless of our/your Eph story, it undoubtedly was marked by interactions with a kind, caring, charismatic, mentor who became a friend. And that he truly was to so many of us. A scholarly mentor for sure, but first and foremost, a friend. Many of us have shared long, late-night hours with him working on projects or discussing deeper issues of life. His most treasured word, possibly his guiding signpost, was “kindness.” He lived and breathed a deep affection and kindness to all – and we were the beneficiaries.
Eph’s career achievements are astonishing. His research, which encompasses almost all aspects of heat transfer, has been published in over 850 peer-reviewed journal papers. He has supervised more than 100 PhD students, and over 250 MS students. His work is widely cited, with over 40,000 current citations. These are numbers that place him at the very top in the field of heat transfer. But behind those numbers is a remarkable journey.
He received his B.S. degree from MIT in 1948 at the age of 19. He then completed an MS at MIT in1949 and an MA and PhD at Harvard in 1950 and 1952, respectively. His doctoral thesis advisor was H.W. Emmons. He began his professional career at Raytheon, working on a number of heat transfer problems including radar, the first microwave oven, and electronics cooling. He then was employed at NACA (now NASA) where he began to appreciate and master the importance and skills of computation. His work at NACA involved fundamental studies in both heat transfer and fluid mechanics. At NACA, he was one of the early practitioners of numerical solution techniques. He used to tell us about how early numerical computations of boundary layer flows were done by rows of human “computers,” with each row representing a forward step in the marching integration process! Other interesting vignettes he shared with us include how he obtained laminar flow at very high Reynolds numbers by running his experiments in the middle of night when traffic vibrations from the road outside his lab would be lessened. Similarly, his wind tunnel work required so much electricity that he was forced to experiment on Sunday evenings when the load on the municipal electrical grid was sufficiently low to allow his power usage. Did this start his characteristic of working through the night, only to bike home in the early morning?
After moving to the University of Minnesota in 1959, he began the fruitful career we remember him by. His research is exceptional for both its breadth and depth. It is hard to identify an area he was not involved in. His early work included foundational studies in radiation heat transfer, turbulent flows in ducts, natural convection, film condensation, boundary layer flows with separation, laminar-turbulent transitions, forced convective heat transfer with flow over objects, solid-liquid phase change problems, flow and heat transfer in porous media, inverse solutions, thermal optimization, biological heat transfer and fluid flow, development of new numerical modeling techniques, and many more. The list of subtopics would be endless. One of his favorite experimental tools was the naphthalene sublimation technique which allows very detailed measurements of local mass transfer coefficients. For many years, visitors to the mechanical engineering building would get a strong whiff of naphthalene!
Between 1986 and 1988 Eph worked at the NSF, first as Program Manager for Heat Transfer and subsequently as Division Director for the CBET division in the engineering directorate. Those years at the NSF had a profound impact on his thinking. When he returned to the University of Minnesota, he focused his attention on real-world engineering problems and left, to some extent, the world of academic problems. He worked with hundreds (yes, hundreds) of students on industry-inspired problems. He applied his deep and broad knowledge to solve the toughest problems companies presented to him. Simultaneously he fostered in his students an intellectual curiosity and a diligence that served them for life. Companies would flock to him for help and advice, and Eph would help them all, asking little or nothing from them in return for his effort.
Eph’s record of service to the heat transfer community is a fitting counterpart to his research record. He coauthored one of the first graduate-level textbooks on radiative heat transfer. He served as the Senior Technical Editor of the ASME Journal of Heat Transfer between 1972 and 1980. Along with one of us (W.J. Minkowycz) he co-founded the journal Numerical Heat Transfer in 1979 to serve as a forum for the dissemination of ideas in the emerging field of computational fluid dynamics and heat transfer. During his NSF years, he helped to reorient heat transfer researchers away from contrived problems of academic interest to real-world problems of practical importance. Many young researchers were motivated by him to study heat transfer problems in areas such as manufacturing processes and microelectronic packages.
His awards are too numerous to list here but we note that he received the prestigious Max Jakob award in 1976. He also was an elected member of the National Academy of Engineering. It was, however, the student-elected awards that he cherished most. He won numerous teaching awards – many readers of this memorial fondly remember the time that they learned from Eph. Teaching was one of his greatest joys, experiencing and conveying “Eureka” insights to his students in the classroom and the laboratory.
Eph is survived by his wife and daughter…. as well as hundreds of his academic progeny. He is a man who exhausts superlatives. He certainly was the “father of modern heat transfer.” But he is so much more than that. We thank him for being a friend, a family member, and a mentor. We, the undersigned, acknowledge many others could be cosigned here and we acknowledge your presence in spirit if not in typeset.
Goodbye Eph, we miss you.
J.M. Gorman University of Minnesota
J.P. Abraham University of St. Thomas
S. Acharya Illinois Institute of Technology
T. Avedisian Cornell University
B.R. Baliga McGill University
A. Bejan Duke
M. Charmchi University of Massachusetts Lowell
P. Cheng Shanghai Jiaotong University
J.H. Davidson University of Minnesota
V.K. Dhir UCLA
W.K. Durfee University of Minnesota
A. Faghri University of Connecticut
M. Faghri University of Rhode Island
A. Ghajar Oklahoma State
R. Goldstein University of Minnesota
J. Hong University of Minnesota
S. Kang Boyd Corporation
J. Kim University of Maryland
U. Kortshagen University of Minnesota
J.R. Lloyd Michigan State University
W.J. Minkowycz University of Illinois, at Chicago
M. Molki Southern Illinois University Edwardsville
J. Mostaghimi University of Toronto
J.Y. Murthy UCLA
T. Myrum retired
M. Ohadi University of Maryland
G. Peterson Georgia Institute of Technology
B. Plourde University of St. Thomas
S. Ramadhyani retired
R. Schmidt retired, IBM
W.Q. Tao Xi'an Jiaotong University, China
T. W. Simon University of Minnesota
J. Stark 3M Corporation
K. Tamma University of Minnesota
K. Vafai University of California, Riverside
S. Muscanto retired