Remembering Rolf Sabersky, 1920‑2016

Rolf Sabersky, professor of mechanical engineering, emeritus, died on October 24. He was 96 years old.

Sabersky made pioneering contributions to our understanding of boiling heat transfer, free convection, granular flows, and indoor air quality. He taught courses in thermodynamics, fluid mechanics, and heat transfer.

Sabersky earned his bachelor's, master's, and PhD degrees in mechanical engineering from Caltech in 1942, 1943, and 1949, respectively. He joined the faculty of the Division of Engineering and Applied Science (EAS) as an assistant professor in 1949, became associate professor in 1955, and was named professor in 1961. He retired in 1988.

He was preceded in death by his wife of 70 years, Bettina, who died five months before his passing. Friends and family describe Sabersky as a devoted family man with a gentle manner and a wry sense of humor; colleagues note that he was a gifted teacher and a mentor to students and junior faculty members alike.  

"Rolf was just a wonderful person who wanted me to succeed and for my colleagues to succeed," says Melany Hunt, Dotty and Dick Hayman Professor of Mechanical Engineering, who first met Sabersky when she joined Caltech as an assistant professor in 1988.  

Born on October 20, 1920, in Berlin, Sabersky attended the Französisches Gymnasium, a French high school founded by the Huguenots in 1689, until he was 17 years old. A few months after his graduation in the spring of 1938, he and his family, who were devoted Jews, emigrated to the United States from Germany.

"We didn't realize how late it was," Sabersky said in a 1990 interview at Caltech. "Soon thereafter, November '38, the so-called Kristallnacht took place."

Sabersky, along with his parents, brother, and sister, stopped first in Switzerland, then went to Los Angeles, where Sabersky had been accepted as a student at Caltech. There, he became a member of Dabney House. "From '39 on, I've been here ever since, every day," he said in the 1990 interview. "Pretty much every day of my life, I've been on campus since that day."

The bombing of Pearl Harbor during his senior year brought the war to the United States, and suddenly Sabersky—who was not yet a citizen—was legally an "enemy alien." A group of students organized to guard the campus, which housed several war-related projects. Sabersky joined the group but, because of his citizenship status, he was deemed unable to participate as a guard. Instead, he volunteered as the group's secretary until the student-run group was replaced by professional guards. Later, as a graduate student, Sabersky joined the campus's civil defense unit as a member of the fire brigade, alongside J. E. Wallace Sterling, who would go on to become the director of the Huntington Library and Art Gallery and then the president of Stanford University.

After earning his master's degree, Sabersky took his one professional turn outside of academia, accepting a job offer from Aerojet, a rocket and missile propulsion manufacturing company that had been founded by Theodore von Kármán in 1942. At the time, von Kármán was the director of what was then called the Guggenheim Aeronautical Laboratories of the California Institute of Technology (GALCIT), and so the nascent company—which resided in an automobile agency near campus that had been left vacant by the war—included many faculty and students from the Institute. At Aerojet, Sabersky worked on the development of sustained-duration liquid-rocket engines, building personal and professional connections that would last for the rest of his career. Decades later, he met with former Aerojet colleagues for regular lunches at the Athenaeum.

Sabersky met his future wife, Bettina Schuster, while visiting his sister Lore at the University of California, Berkeley, where Bettina was a graduate student studying romance languages. Like Sabersky, Bettina had been born in Germany but ended up in California after fleeing the Nazis.

In 1946, with the war over, the newly married Sabersky returned to Caltech and resumed his studies. In 1949, he received a PhD in mechanical engineering for his work on axial flow compressors, which use spinning airfoils to continuously pressurize gases. The compressors are still used today in jet engines.

Over his career, Sabersky made pioneering contributions to our understanding of boiling heat transfer, free convection, granular flows, and indoor air quality—work for which he received the Heat Transfer Memorial Award from the American Society of Mechanical Engineers in 1977. In particular, his research focused on what he described as "funny fluids"—materials such as ketchup, which have complicated flow characteristics that manufacturers are keen to understand. He was the author of two popular textbooks, Elements of Engineering Thermodynamics, and Fluid Flow: A First Course in Fluid Mechanics, which he coauthored with Allan Acosta, Richard L. and Dorothy M. Hayman Professor of Mechanical Engineering, Emeritus.

Sabersky taught courses in thermodynamics, fluid mechanics, and heat transfer for nearly four decades at Caltech, and was beloved by his students—in 2011, former students organized a dinner in his honor. He was equally appreciative of them and of Caltech, Hunt says. "He was ever grateful to Caltech for everything that Caltech had done for him, and he wanted to pass that along."

Sabersky is survived by his two daughters, Carol and Sandy, and their families.