Lloyd MacGregor Trefethen (March 15, 1919 – November 6, 2001) was an American expert in

fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...

known for his invention of the heat pipe and his research on the Coriolis effect and card shuffling. He worked for many years as a professor of mechanical engineering at Tufts University.

Early life and education

Trefethen was born on March 15, 1919, in Waltham, Massachusetts. He graduated from the

Webb Institute Webb Institute is a private college focused on engineering and located in Glen Cove, New York. Each graduate of Webb Institute earns a Bachelor of Science degree in naval architecture and marine engineering. Successful candidates for admission r ...

in 1940, and went to the Massachusetts Institute of Technology for a master's degree in

naval engineering Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and o ...

. During World War II, poor eyesight made Trefethen ineligible for the Navy, so instead he signed up for the United States Merchant Marine. There he met Florence Newman, a Navy codebreaker who later became a professor of English at Tufts. They married in 1944. Their son

Lloyd N. Trefethen Lloyd Nicholas Trefethen (born 30 August 1955) is an American mathematician, professor of numerical analysis and head of the Numerical Analysis Group at the Mathematical Institute, University of Oxford. Education Trefethen was born 30 August 19 ...

later became a notable mathematician; they also had an older daughter, quilter Gwyned Trefethen. In 1950, Trefethen completed a Ph.D. at the University of Cambridge. Although his initial plan of research was on cooling turbine blades, his eventual dissertation was ''Heat Transfer Properties of Liquid Metals'', and his work sparked an ongoing interest in magnetohydrodynamics at Cambridge.

Career and later life

On returning to the US, Trefethen took a managerial position at the National Science Foundation before joining Harvard University as an assistant professor of engineering in 1954. He moved to Tufts University in 1958, where he became a full professor and the chair of the mechanical engineering department. He retired in 1989. Trefethen died on November 6, 2001.

Contributions

Trefethen was known for his research on

surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to f ...

in liquid droplets, and he became one of the independent inventors of the heat pipe. In 1963 he produced an award-winning educational film, ''Surface Tension in Fluid Mechanics'', for

Encyclopædia Britannica Films Encyclopædia Britannica Films (also named EB Films for short) was the top producer and distributor of educational 16 mm films and later VHS videocassettes for schools and libraries from the 1940s through the 1990s (by which time the internet ...

. Trefethen's contributions to fluid mechanics also included widely reported experiments on the folklore claims that the

Coriolis force In physics, the Coriolis force is an inertial or fictitious force that acts on objects in motion within a frame of reference that rotates with respect to an inertial frame. In a reference frame with clockwise rotation, the force acts to the ...

can cause the vortex in a drain to rotate in opposite directions in the northern and southern hemispheres. Beyond fluid dynamics, Trefethen's publications include a paper with his son

on the Gilbert–Shannon–Reeds model, a mathematical model of shuffling playing cards. In contrast to earlier research suggesting that seven riffles are needed to remove any patterns from an unshuffled deck of cards, Trefethen and Trefethen showed that, in their model of the problem, five riffles are enough.

Recognition

Trefethen was a

Fellow of the ASME The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing ...

. In 1999, a special issue of the ''Journal of Fluids Engineering'' was dedicated to Trefethen to honor his 80th birthday.

Selected publications

References

{{DEFAULTSORT:Trefethen, Lloyd M. 1919 births 2001 deaths People from Waltham, Massachusetts American mechanical engineers Webb Institute alumni MIT School of Engineering alumni Alumni of the University of Cambridge Harvard University faculty Tufts University faculty Fellows of the American Society of Mechanical Engineers

Lloyd Lloyd, Lloyd's, or Lloyds may refer to: People * Lloyd (name), a variation of the Welsh word ' or ', which means "grey" or "brown" ** List of people with given name Lloyd ** List of people with surname Lloyd * Lloyd (singer) (born 1986), American ...

United States Merchant Mariners of World War II