Combustion Processes in a Medium-Speed Diesel Engine

A detailed knowledge of the combustion processes is essential for the continued development of the medium-speed diesel engine. This paper describes the development and use of electronic and photographic techniques on a constant volume bomb and an 8-in bore diesel engine. Both Schlieren and direct photography were used to study fuel-spray formation and penetration. An equation to predict the motion of vapour in the spray is proposed. Using the knowledge gained, improvements of combustion in existing engines and its extension to high brake mean effective pressure (b.m.e.p.) engines are discussed. Of particular interest are the results obtained from engines of up to 12 1/2-in bore running at a b.m.e.p. of 300 lb/in².