Theodore Yaotsu Wu (; March 20, 1924 – December 16, 2023) was a Chinese-born American engineer. He was a Professor of

Engineering Science Engineering physics (EP), sometimes engineering science, is the field of study combining pure science disciplines (such as physics, mathematics, chemistry or biology) and engineering disciplines (computer, nuclear, electrical, aerospace, medica ...

at the

California Institute of Technology The California Institute of Technology (branded as Caltech) is a private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small group of institutes ...

. His research contribution included compressible fluid flow, free-streamline theory of cavities, jets and wakes,

water waves In fluid dynamics, a wind wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result of the wind blowing over the water's surface. The contact distance in the direction of the wind is k ...

and free-surface flows, mechanics of fish swimming and bird/insect flight, wind and ocean-current energy, and

internal waves Internal waves are gravity waves that oscillate within a fluid medium, rather than on its surface. To exist, the fluid must be stratified: the density must change (continuously or discontinuously) with depth/height due to changes, for example, in ...

in the ocean.

Early life

Wu came from a Chinese scholar family. His father had a degree in economics and finance, his mother graduated from high school and majored in literature, while his grandfather was a Chinese physician. During the Japanese invasion, the Japanese airplanes flying overhead eventually inspired him to enter aeronautics in the university.

Education and career

Wu received his BSc in 1946 from National Chiao Tung University in Shanghai (now

Shanghai Jiao Tong University Shanghai Jiao Tong University (SJTU) is a public university in Shanghai, China. It is affiliated with the Ministry of Education of the People's Republic of China, Ministry of Education of China. The university is part of Project 211, Project 98 ...

), and spent one year teaching upon graduation. In January 1948 he arrived in the U.S. and enrolled at

Iowa State University Iowa State University of Science and Technology (Iowa State University, Iowa State, or ISU) is a Public university, public land-grant university, land-grant research university in Ames, Iowa, United States. Founded in 1858 as the Iowa Agricult ...

and graduated with an MS in December the same year. After Iowa State, Wu went to

Caltech The California Institute of Technology (branded as Caltech) is a private university, private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small g ...

, where he shared an office with

Julian Cole Julian David Cole (April 2, 1925 – April 17, 1999) was an American mathematician. He is known for his groundbreaking work in mathematical applications to aerodynamics and transonic flow, and in non-linear equations more generally. He graduated 3 ...

. Wu was involved in the research group headed by

Paco Lagerstrom Paco Axel Lagerstrom (February 24, 1914 – February 16, 1989) was a Swedish-American applied mathematician and aeronautical engineer. He was trained formally in mathematics, but worked for much of his career in aeronautical applications. He ...

, where they developed further the asymptotic perturbation method pioneered by

Ludwig Prandtl Ludwig Prandtl (4 February 1875 – 15 August 1953) was a German Fluid mechanics, fluid dynamicist, physicist and aerospace scientist. He was a pioneer in the development of rigorous systematic mathematical analyses which he used for underlyin ...

. Wu received his PhD in (1952), subsequently worked as a research fellow at Caltech for three years, and developed interest in water waves and

hydrodynamics In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in ...

, due to inspiration from then

Qian Xuesen Qian Xuesen ( zh, s=钱学森; December 11, 1911October 31, 2009; also spelled as Tsien Hsue-shen) was a Chinese aerospace engineer and cyberneticist who made significant contributions to the field of aerodynamics and established engineering ...

and

von Karman The term () is used in German surnames either as a nobiliary particle indicating a noble patrilineality, or as a simple preposition used by commoners that means or . Nobility directories like the often abbreviate the noble term to ''v.'' I ...

. After three years Wu became an assistant professor of applied mechanics (1955) at Caltech. In 1960, under the influence of

G. I. Taylor Sir Geoffrey Ingram Taylor Order of Merit, OM Royal Society of London, FRS FRSE (7 March 1886 – 27 June 1975) was a British physicist and mathematician, who made contributions to fluid dynamics and wave theory. Early life and education Tayl ...

and

James Lighthill Sir Michael James Lighthill (23 January 1924 – 17 July 1998) was a British applied mathematician, known for his pioneering work in the field of aeroacoustics and for writing the Lighthill report in 1973, which pessimistically stated t ...

, Wu started to work on fish locomotion and bird flight ( biofluiddynamics). During his time at Caltech he also contributed to the field of

naval architecture 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 op ...

and was involved in the International Towing Tank Conferences. Wu was elected a member of the

United States National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. It is part of the National Academies of Sciences, Engineering, and Medicine (NASEM), along with the National Academy of Sciences (NAS) and the ...

in 1982.

Later life and death

Wu retired in 1996, but remained very active after his retirement. He died on December 16, 2023, at the age of 99.

Selected publications

* *

References

External links

* Wu a
Caltech
(bad link accessed November 19, 2024.) * Interview with Theodore Y. Wu, 2002
Caltech Oral Histories
{{DEFAULTSORT:Wu, Theodore Y. 1924 births 2023 deaths California Institute of Technology alumni California Institute of Technology faculty Chinese emigrants to the United States Fluid dynamicists Iowa State University alumni National Chiao Tung University (Shanghai) alumni Members of the United States National Academy of Engineering Foreign members of the Chinese Academy of Sciences California Institute of Technology fellows