Recent Developments in High-Speed Oil Engines *

Abstract

The developments since the author's paper to the Institution in 1932 are reviewed under the subdivisions: combustion chamber design; injection systems; fuels. While few novel features can be reported under combustion chamber design, the growth of knowledge concerning injection systems and the properties of fuels has been considerable. The processes in fuel-injection systems are now well understood, while the conditions governing the break-up of fuel sprays are now also reasonably clear. The fundamentals of combustion and what determines ignition lag still remain obscure; the interaction of break-up of spray and course of combustion are also indefinite, and trial-and-error methods must still be employed. On the other hand, the cetane scale for assessing the suitability of fuels has been introduced. Reference is made to electrical indicators and the determination of impact loading on running gear during combustion. Two-stroke working and supercharging are discussed.