In Memoriam: Professor Peter Griffith (1927–2022)

Journal of Heat Transfer

Fig. 1

Peter Griffith, ca. 1966. Courtesy MIT Museum.

AIChE-ASME Heat Transfer Conference in 1968 and received
the conference’s Best Paper Award for it [9]. The paper was later
published in the Journal of Heat Transfer.
With his student Clark (“Corky”) Graham, Pete measured thedrop size distributions during dropwise condensation of water
onto treated copper [10]. They reported nucleation site densitiesof 200  106=cm2, and, with a model, they determined that thedominating thermal resistance shifted from liquid resistance tointerfacial resistance as the atmospheric pressure was reduced.
This paper remarks “The picture which emerges is just as complicated as the boiling picture, and just as difficult to reduce to anengineering correlation.”
Pete’s work on nucleate boiling mechanisms also proceeded
through a combination of experiments and modeling. His two-partpaper with Chi-Yeh Han [11] develops very detailed transient
conduction models for the liquid surrounding a growing bubble
and compares them to his characteristically rigorous measurements. These bubble growth data were acquired using high-speed
photography through a so-called “fluid crystal”—an enclosing
glass box filled with the same liquid as the test section to eliminate image distortions caused by refraction. The boiling surface
preparation is documented in excruciating detail, for example,
noting that the diamond compound “should be placed at the centerof the grinding wheel and diluted by kerosene.” The prediction of
the data by the theory is excellent.
Yet, this paper notes the inherent randomness of the boilingprocess and states that the good agreement is “partly fortuitous.”
Additional remarks state that, while the theory assumes a periodic
bubble departure, “this is hardly the case” and that “the procedures used here are far too complicated to be of use in prediction
in a practical problem.” Thus, this excellent and well-cited paper

C 2022 by ASME
Copyright V

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Professor Peter Griffith died on Mar. 5, 2022, at the age of 94.
Pete served in the heat transfer laboratory of the Massachusetts
Institute of Technology for more than 60 years. Pete’s researchencompassed two-phase flow, nucleate boiling, dropwise condensation, heat transfer to supercritical fluids, water hammer, andnuclear reactor safety. He also consulted extensively on thermal
and nuclear engineering.
Pete joined the heat transfer lab as a doctoral student in 1952,and he went on to become the longest-serving faculty member inthe lab’s 150-year history [1]. The heat transfer lab is in a basement, but Pete nevertheless kept his office inside this lab, rather
than taking a more sumptuous office on MITs Great Courtyard.
As a result, Pete engaged with every student who worked in thelab up to 2012. He provided technical advice, experimental guidance, mentorship, and critical feedback without hesitation—nomatter who was the student’s actual advisor. His influence,
accordingly, was enormous.
Pete Griffith was born in London, England in 1927, and hegrew up in Huntington, Long Island, in New York State. As achild, Pete was known as a tinkerer, even building forges, and hespent much time in the woods near his home [2]. Pete enrolled at
New York University in 1945, immediately after high school, but wasdrafted into the U.S. Army Air Corps one year later. He served eighteen months as a finance clerk typist in Iceland, Greenland, and Labrador, then returned to NYU and received his BME in 1950 [3]. He
took a master’s degree at the University of Michigan in 1952. Petethen came to MIT for ScD work, completing his dissertation The
dynamics of bubbles in nucleate boiling in 1956 under the guidanceof Warren Rohsenow. Upon graduation, Pete immediately joined the
MIT mechanical engineering faculty as an assistant professor.
One of Pete’s earliest goals was to understand the regimes of
two-phase flow in pipes. Working with his student Graham
Wallis, Pete built an 18-foot-tall Plexiglas pipe through which heflowed a mixture of air and water in varying proportions [4]. The
tube enabled direct visualization of the flow patterns at different
gas/liquid flow rates, and with associated pressure taps, he could
map both the flow regime and the head loss that accompanied it.
Pete spent countless hours making small adjustments to the flow
rates and noting the effect [5]. He mapped out the conditions leading
to bubbly flow, slug flow, and misty annular flow. Pete was to returnto large-scale pipe flow experiments many times during his career. At
a smaller scale, with his student Mikio Suo, he mapped flow patterns
in capillary tubes, combining dimensional analysis with data for combinations of water or heptane with nitrogen, air, or helium [6].
These flow regime maps were of interest for their importance toflow boiling, which was a major focus of the MIT heat transfer lab
at that time, especially in connection with nuclear reactor cooling.
The metal tubes used in boiling work were of course opaque, andso Rohsenow referred to Pete’s substitution of low-temperaturegas–liquid flow in a transparent pipe as “Take a peek” [7].
During the 1960s and early 1970s, Pete’s research also encompassed nucleate boiling, film and dropwise condensation, and heattransfer under supercritical flow in tubes. In 1968, Pete and his
student Bharat Shiralkar reported the first observations ofdegraded heat transfer in supercritical CO2 using a flow loop theybuilt in the heat transfer lab [8]. Degraded heat transfer had previously been seen in water and a few other fluids but seemed absent
from CO2 experiments, which had until then used relatively highinlet temperatures. This paper is a reminder of the early state ofheat transfer research in supercritical fluids at the time. The literature was divided as to whether thermal conductivity did or did not
spike at the pseudocritical temperature—many regarded this now
confirmed phenomenon as merely a measurement error caused bylarge density differences. Additionally, the complex dependenceof heat transfer behavior on the “path” taken past the critical point
was still being explored. Pete presented this research at the 10th

080101-2 / Vol. 144, AUGUST 2022

Fig. 2 Pete in 2021. Courtesy Kat Griffith.

across the full breadth of the mechanical engineering curriculum,
including many semesters in introductory solid mechanics. Hispassion, however, was experimentation. From 1962 to 1996, he
led a senior-level lab subject that gave students a few weeks towork on each of several different experiments. These experiments
involved diagnosing, explaining, and modeling the behavior ofthermal systems, some steam-operated, and most drawn directlyfrom Pete’s work as a consultant.
When Pete retired, the mechanical engineering department createdan endowed award, The Peter Griffith Prize for Outstanding Undergraduate Experimental Work, to honor his decades of contributions
to teaching experimentation. Pete’s excitement in creating new
knowledge and advising students was such that he continued toengage in research and teaching for many years after retiring.
Pete kept his home life well separated from his job. According
to his daughter, Kat Griffith, he never brought MIT work to his
house [17]. His time at home went entirely to family life. One
may wistfully observe that, in this way, Pete was quite unlike
most professors, then or now.
Pete commuted between home and work on his bicycle, which
he rode through Belmont and Cambridge every day, all year. His
bike was not a fancy racing bike or a techy recumbent, but simply
a sturdy upright bike with a cargo rack over the back wheel. And,whenever time allowed, Pete retreated to his cabin on 100 acres of
undeveloped land in Vermont, where he’d spend much time in thewoods—cutting trees, clearing trails, and collecting mushrooms.
In addition to his daughter Kat, Pete is survived by his son-inlaw, Soren Hauge, his stepdaughter and son-in-law, Sara and Stephen Young, and five grandchildren.
John H. Lienhard, V
Massachusetts Institute of Technology,
Cambridge, MA 02139
email: lienhard@mit.edu
C. Thomas AvedisianCornell University,
Ithaca, NY 14850
Portonovo S. Ayyaswamy
University of Pennsylvania,
Philadelphia, PA 19104
Vijay K. Dhir
University of California,
Los Angeles, CA 90095
Transactions of the ASME

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also reveals the tension Pete saw between highly complex modeling and the problems engineers actually need to solve.
Pete once characterized overcomplicated theories this way:
Two kids who live next door to each other each build a tree house.
Then they string up a tin-can telephone between the treehouses.
One kid talks into a can while the friend listens to the other can,and after speaking the first kid leans out of the treehouse and yells“Did you hear me?” To Pete, models that served only to show off
a theoretical principle were as unhelpful to engineers as the tincan phone was for children’s communication [12].
This impatience with unnecessary theoretical complexity permeated Pete’s teaching at MIT. He emphasized that students
should understand the size of physical variables (say, the relative
magnitudes of thermal resistances) and that they should focus on
picking out primary phenomena and modeling them in a straightforward way. He applied this philosophy in teaching the MIT twophase flow class. Gone were the repetitive recitations of formal
definitions and complex models for steam-water mixture
behavior—rather, Pete created practical demonstration apparatuses (some being similar to Rube Goldberg machines), and hethen challenged students to deduce the principal physical phenomena at play. Similarly, he once advised a young colleague not to“teach procedure” for solving problems [12], since procedures(graphical integration, say) are constantly replaced by more efficient, up-to-date techniques (numerical procedures, say).
Similarly, Pete’s doctoral exam questions never tested how
much math a student could do. Instead, he’d typically adapt aproblem from his consulting work and ask candidates to try to
explain what was going on. He questioned students with a lighttouch—and many jokes—once saying: “You don’t find out how
much someone knows by scaring them to death” [13]. Yet, despite
his easygoing manner, Pete could make hard judgments. He could
be tough with colleagues and could draw firm lines with students.
In the 1970s and later, nuclear reactor safety came to occupy alarge portion of Pete’s time. He consulted for both the U.S. Energy
Research and Development Administration and the U.S. Nuclear
Regulatory Commission (NRC), as well as many companies andseveral federal labs. At the NRC, Pete was an often-sought voiceon the extramural advisory committees that guided technicalinvestigations of critical regulatory issues. His consulting encompassed diverse topics in thermohydraulics, such as liquid metal
fast breeder reactors, natural circulation, spallation, advanced lightwater reactor design, and critical heat flux phenomena.
Pete’s final papers, published after his retirement in 1997 withhis student Marc Hodes and Professor Kenneth A. Smith, dealt
with salt fouling by buoyancy-driven supercritical water flows[14]. Pete spotted this research question while visiting a startup
company that was developing supercritical water oxidation as a
low-temperature alternative to incineration [15]. Long after Peteretired, he was still consulting for the founder of this company, on
sludge management for the city of Orlando, Florida.
Pete’s excellent research, and his practicality, were widely
respected in the heat transfer community. He received the 1975
ASME Heat Transfer Memorial Award “for his outstanding contributions to the art of heat transfer in two-phase flow, boiling,
and condensation.” Similarly, a 1984 Journal of Heat Transfer
paper by Pete and his student Robert Bjorge received the best paper
award of the ASME Heat Transfer Division and was selected forthe 1986 Melville Medal, ASME’s highest honor for an original
research paper. This elegant paper, not quite six pages long, provides an experimentally validated analytical model for the onset ofwater hammer caused by steam bubble collapse in a stratified horizontal pipe [16]. Remarkably, the model required no empirical fitting beyond a single adjustment to the heat transfer coefficient correlation. The simplicity of the work stands in sharp contrast to thecomplex models that Pete published in the early 1960s.
During his long career, Pete supervised 39 doctoral dissertations, 91 master’s theses, and 78 bachelor’s theses, including
many nuclear engineering students. He started teaching at MIT as
an instructor in 1954 and continued until he retired. Pete taught

Neil E. Todreas
Massachusetts Institute of Technology,
Cambridge, MA 02139

Marc Hodes
Tufts University,
Medford, MA 02155
Jeffrey S. Horowitz
Poway, CA
Gail E. Kendall
Hong Kong Climate Change Forum,
Hong Kong
John S. Maulbetsch
Maulbetsch Consulting,Atherton, CA 94027

John Rose
Queen Mary University of London,
London E1 4NS, UK
Zvi RuderWorld Scientific Press,
Cary, NC 27518
Senator John E. Sununu
New Hampshire
Hock E. Tan
Broadcom Inc.,San Diego, CA 95131

Journal of Heat Transfer[1] Lienhard, J. H., 2003, “A History of the MIT Heat Transfer Laboratory,”
Heat Transfer Eng., 24(2), pp. 3–17.
[2] MIT News, 2022, “Professor Emeritus Peter Griffith, A Pioneer in Heat
Transfer and Fluid Mechanics, Dies at 94,” MIT News, Cambridge, MA,
accessed May 1, 2022, https://news.mit.edu/2022/professor-emeritus-petergriffith-dies-0315[3] Griffith, P., 1956, “The Dynamics of Bubbles in Nucleate Boiling,” Sc.D.
thesis, Massachusetts Institute of Technology, Cambridge, MA.
[4] Griffith, P., and Wallis, G. B., 1961, “Two-Phase Slug Flow,” ASME J. Heat
Transfer-Trans. ASME, 83(3), pp. 307–318.
[5] Maulbetsch, J. S., 2022, Comments at Pete’s memorial gathering, Apr. 10.
[6] Suo, M., and Griffith, P., 1964, “Two-Phase Flow in Capillary Tubes,”
ASME J. Basic Eng., 86(3), pp. 576–582.
[7] Rohsenow, W. M., 1997, Anecdote at Pete’s retirement event, May.
[8] Shiralkar, B. S., and Griffith, P., 1969, “Deterioration in Heat Transfer to Fluids at Supercritical Pressure and High Heat Fluxes,” ASME J. Heat TransferTrans. ASME, 91(1), pp. 27–36.
[9] The written record is vague as to which of Pete’s conference papers received
the award, but only this one fits the chronology.
[10] Graham, C., and Griffith, P., 1973, “Drop Size Distributions and Heat Transfer
in Dropwise Condensation,” Int. J. Heat Mass Transfer, 16(2), pp. 337–346.
[11] Han, C.-Y., and Griffith, P., 1965, “The Mechanism of Heat Transfer in
Nucleate Pool Boiling–Part I: Bubble Initiation, Growth and Departure,” Int.
J. Heat Mass Transfer, 8(6), pp. 887–904.
[12] Comments made to John Lienhard, mid-1990s.
[13] Comment reported by Jeffrey Horowitz.
[14] Hodes, M., Griffith, P., Smith, K. A., Hurst, W. S., Bowers, W. J., Jr., andSako, K., 2004, “Salt Solubility and Deposition in High Temperature andPressure Aqueous Solutions,” AIChE J., 50(9), pp. 2038–2049.
[15] MODAR, Inc., founded by Professor Michael Modell of MIT Chemical
Engineering.
[16] Bjorge, R. W., and Griffith, P., 1984, “Initiation of Water-Hammer in Horizontal and Nearly Horizontal Pipes Containing Steam and Subcooled Water,”
ASME J. Heat Transfer-Trans. ASME, 106(4), pp. 835–840.
[17] Griffith, K., 2022, Comments at Pete’s memorial gathering, Apr. 10.

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Borivoje B. Mikić
Massachusetts Institute of Technology,
Cambridge, MA 02139

References