The Scope for Increasing the Efficiency of Automotive Engines through Combustion Research

摘要

This report describes the evolution of a program of research in combustion, the broad objective of which was to assist in effecting improvements in the thermal efficiency of automotive engines without undue penalties in other aspects of performance, and at an acceptable cost. The gasoline engine receives first priority, and an extensive review of possible routes for improvement narrowed the field to attempting to increase compression ratios in conjunction with the use of leaner mixtures. The barrier to such developments was the slowness of combustion of lean mixtures. The time of combustion is shown theoretically to depend principally on a flame-stretching factor, which in turn is shown to depend on velocity gradients in the unburnt gas. This treatment of engine combustion is significantly different from the way in which other investigators are approaching the matter.