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Fellows Directory

Kenneth Bray

Kenneth Bray

Professor Kenneth Bray FRS


Elected: 1991


Kenneth Bray has made seminal contributions to the study of gas flows accompanied by chemical reactions and relaxation effects. His early work dealt with flows of dissociating and ionising gases, with special reference to hypersonic flight in the atmosphere. This research was the first to identify the phenomenon of ‘sudden freezing’ of internal molecular energy modes and chemical reactions during the expansion and rapid cooling of hot gases in de Laval nozzles, with implications for the design of rocket motors and high-speed wind tunnels. The effect is also central to the operation of gas dynamic lasers. Work on the de-excitation of molecular vibrational states far from equilibrium followed. Some of his most important achievements lie in extensive studies of turbulent combustion in gases, using probability density function ideas, paying careful attention to the couplings that exist between fluid-mechanical behaviour and combustion-energy release, and exploiting both theory and experiment. This important work has achieved worldwide recognition.

Interest and expertise

Subject groups

  • Engineering
    • Engineering, mechanical
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