This paper is intended to supplement a part of the paper by Mr. F. W.
Armstrong on ‘The aero engine and its prospects—fifty years after Griffith’.
It deals in more detail with Dr. A. A. Griffith's early ideas on the
aerodynamic aspects of turbomachines.
Even with reasonably optimistic use of materials and operating
temperatures it was essential in 1926 that very high component efficiencies
were obtained to make the gas turbine competitive with the piston engine on
fuel consumption. Griffith believed that efficiencies of over 90% could be
obtained for the compressor and turbine components, if the correct attention
was given to the aerodynamic design of the blades. His 1926 report on ‘An
aerodynamic theory of turbine design’ showed how such high efficiency
designs should be carried out and gave appropriate formulae for the
compressor and turbine efficiencies.