James Lighthill FRS (1924 - 1998)

James Lighthill FRS (1924 - 1998)

Sir James Lighthill was born on 23 January 1924 in Paris where his father , Ernest Balzar Lighthill was working as a mining engineer. Lighthill was educated at Winchester College and, at the age of 15, he won a scholarship to Trinity College, Cambridge but did not start studying until 1941 at the age of 17. He graduated with a BA in 1943. Following college Lighthill worked at the Aerodynamics Division of the National Physical Laboratory at Teddington until 1945.

Lighthill specialised in fluid dynamics and was elected a fellow of Trinity College in 1945 and he held this fellowship until 1946. In 1946 he was appointed as a Senior Lecturer at Manchester University and there he set up a very strong fluid dynamics group which soon dominated research in fluids. In 1950 Lighthill was promoted to Beyer Professor of Applied Mathematics at Manchester University until 1959 when he moved to become director of the Royal Aircraft Establishment at Farnborough. There he worked on the development of television and communications satellites, and on the development of manned spacecraft.

Outstanding contribution to science

Concorde supersonic airliner

Lighthill's work at the Royal Aircraft Establishments was used in the development of the Concorde supersonic airliner.

Kinematic waves, fluid and traffic flow

In 1955, together with his doctoral student G. B. Whitham, Lighthill set out the first comprehensive theory of kinematic waves (an application of the method of characteristics), with a multitude of applications, prime among them fluid flow and traffic flow. 

Dimensional aerofoil theory and supersonic flow around solids

His early work included the two dimensional aerofoil theory and supersonic flow around solids of revolution.

Shock and blast waves

In addition to the dynamics of gas at high speeds he studied shock and blast waves.

Aeroacoustics

He founded the subject of aeroacoustics, a subject vital to the reduction of noise in jet engines. Lighthill's eighth power law states that the acoustic power radiated by a jet engine is proportional to the eighth power of the jet speed. He also was the father of non-linear acoustics, and showed that the same non-linear differential equations could model both flood waves in rivers and traffic flow in highways. 

Manchester

Lighthill at Manchester

In 1946 he was appointed as a Senior Lecturer and later a Professor of Fluid Mechanics at The University of Manchester where he worked for 13 years. At Manchester he set up a very strong fluid dynamics group which soon dominated research in fluids.

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Sir J Lighthill. Acoustic Streaming, p9, 1978.
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