There Will Be Heated Discussions

Thermal Scientists Are Gathering for a Symposium Honoring Chancellor Tien

by Robert Sanders

Chancellor Tien's 60th birthday was July 24, but the hottest birthday bash yet takes place Nov. 14 when more than a hundred of his colleagues, former students and students of former students fly in from around the world for a symposium in honor of Tien the scientist.

The meeting features more than 60 speakers discussing the latest work in heat transfer and thermal science, a field that Tien made his own during a 36-year career. Among the many colleagues attending is one of the pioneers of the field, Ernst R. G. Eckert, now 91 and Regents' Professor Emeritus of Mechanical Engineering at the University of Minnesota, who wouldn't hear of missing the celebration.

Though Tien has achieved international fame since taking the reins as chancellor, his scientific achievements have remained relatively unheralded outside his field.

In Japan though, they consult his papers in designing their celebrated magnetic levitation trains.

His work has also contributed to the design of insulating tiles for the Space Shuttle, emergency cooling systems for nuclear reactors and the safety of high rise buildings in fires.

"Tien has had a tremendous impact on a lot of people, and on the whole of thermal science," said Richard Buckius, who got his PhD from Berkeley in 1975 while working with Tien.

He now is a professor of mechanical and industrial engineering at the University of Illinois at Urbana-Champaign.

"A unique aspect of his career is that he has made fundamental contributions (to the theory of thermal science) as well as actual applications.

"He is a visionary who has always understood where to go (in the field), how to make an impact, which problems need to be addressed," said Buckius, who is among those organizing the Nov. 14 meeting.

Since he joined the faculty in 1959, Tien has contributed to nearly every area of heat transfer and thermal science, building an international reputation as one of the top experts in the field, particularly in the area of radiant heat transfer.

He has supervised more than 60 doctoral students and won several teaching awards, published 280 research papers, edited 10 volumes and written one book. He was elected to the National Academy of Engineering at 41.

"He's pretty much made contributions in all the areas where people are presenting at the symposium," said Per Peterson, himself a former student and now an associate professor of nuclear engineering at Berkeley.

Even today, despite his all-consuming job as chancellor, Tien finds time to work with three graduate students in his laboratory in Etcheverry Hall, though it often means lab meetings in the evening or even the dead of night.

Not bad for someone whose main goal as an undergraduate at National Taiwan University was to become a professional basketball player, who devoted half a dozen hours each day to that end and who wiled away his off hours at the movies.

"I wasn't that good a student. I had no time," he admitted during an interview in his office last month.

Despite these extracurricular interests, he graduated in the top five percent of his class, and after a year as a semiprofessional basketball player in Taiwan, he realized his destiny lay elsewhere.

In 1956 he headed off to the U.S. for graduate school, ending up at the University of Louisville in Kentucky on a full scholarship.

A year later he was at Princeton, where he fell into heat transfer mainly because that's where the research support was.

At the time the field was primarily concerned with burning and combustion, such as rocket exhaust and explosions.

Unlike his years in Taiwan, though, he didn't dawdle. He was secretly engaged, and neither family would let the couple marry until he had finished his PhD in mechanical engineering.

"That was a great incentive--I finished in 20 months," said Tien.

He immediately got a job offer from Berkeley, and in rapid succession welcomed his fiancee, Di-Hwa, to the U.S., married her three weeks later, then drove cross country to Berkeley to start his new job.

It was the summer of 1959 and he was 24.

Not everything went as smoothly once he got here. At his first meeting with mechanical engineering division chair Ralph Seban, he was asked to tackle a totally new area of thermal science, thermal radiation.

All hot bodies radiate heat, primarily as infrared radiation, but a detailed understanding of this--detailed enough so that engineers could take account of it in their design--was lacking.

Ironically, this was the one area he flubbed on his PhD orals at Princeton. Despite promises that he would not be quizzed on the developing area, one member of his orals committee posed only 10 questions--each one on thermal radiation.

"I couldn't answer even one question," Tien says. "It was very embarrassing. I thought I had flunked."

In fact it was a pointed message from the professor that "thermal radiation will be a very important area" in the future, a message reinforced by Seban.

"At the time I almost fainted," he says, but time proved them correct. Tien made his reputation in the field of radiative heat transfer.

"That's one of life's twists," said Tien. "Today my message to students is 'Don't close your mind to the advise and experience of senior people.'"

One of Tien's first projects at Berkeley involved the huge Saturn rocket boosters being developed in the 1960s to hoist satellites and eventually humans into space.

He helped estimate the extent to which the exhaust plume would heat the rocket base, work that went into the design of the exhaust nozzles.

Periodically during his career he returned to the space program.

He looked at how best to build satellites so that the huge temperature difference between the sunny and shady sides wouldn't wreak havoc with the temperature-sensitive electronics inside.

And in the 1970s he helped address the first crisis of the Space Shuttle program--how to keep 36,000 insulating tiles glued to the shuttle during the extreme heat of re-entry.

He often brings out a sample shuttle tile as a prop when he talks about the importance of his field of heat transfer. He and other NASA consultants eventually suggested a better way to fire the ceramic tiles to improve their insulating properties and prevent the heat from penetrating to and melting the glue that holds them in place.

With the 1970s also came an increased emphasis on insulation, what with the Arab oil embargo and the skyrocketing price of fuel, and Tien began to look at the effectiveness of new types of insulation and how well they prevented heat loss from buildings. More importantly he moved into studies of "superinsulation." These are materials that can prevent heat flow into the supercold--liquid helium or the liquid oxygen used in Saturn rocket engines--and heat loss from the superhot, such as rocket exhaust.

He notes with pleasure that the Japanese firm Hitachi uses his basic formulas today in the design of magnetic levitation trains, which rely on low-temperature superconductors to generate immense magnetic fields.

He also began working on the spread of fire in urban high rises. Intense fire can ignite distant objects merely from radiated heat. While colleagues at Berkeley, including Brady Williamson and Pat Pagni, looked at other aspects of spreading fires, Tien concentrated on the effects of radiant heat.

His expertise also came into play in the design of emergency core cooling systems for nuclear reactors.

Because of this experience he was called to consult on the Three Mile Island reactor melt-down in 1982, and again when the Ukrainian reactor melted at Chernobyl in 1986.

In both cases officials wanted to know what happened, and whether the core could have melted through the containment vessel and into the ground, a situation known as the China syndrome.

Until 1990 Tien remained a consultant with the U.S. Nuclear Regulatory Commission.

As the semiconductor industry pushed for greater miniaturization, Tien again saw an area where his expertise was needed.

When packing hundreds of thousands of components onto an integrated circuit, you have to think about where the heat will go.

His work in this area led to a new specialization he refers to as microscale thermal phenomena. With the increasing use of short-pulse lasers, which send out a brief burst of energy and heat every millionth or even billionth of a second, he saw the need to understand how heat is dissipated on such small time scales.

This can be of extreme importance in eye microsurgery or gallstone fragmentation, not to mention semiconductor applications.

As Tien celebrates 36 years in the laboratory, he can look with pleasure across campus at one of his children who is following in his footsteps. Norman Tien, 33, is now a post-doctoral research engineer in the Berkeley Sensor and Actuator Center, and will present a paper at the symposium in honor of his father.

He continues a tradition of academic science that started with Tien's father, who 80 years ago studied physics at Beijing University and later taught in a Chinese university, before becoming a successful financier and banker.

"At first I thought, I'm not ready for this," Tien said about the symposium.

"But I'm very flattered and honored they are doing it."


Copyright 1995, The Regents of the University of California.
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