A detailed knowledge of the combustion processes in internal combustion engines is required if one wishes to further improve on the remarkable development of engine technology and related fuel technology. Such improvements aim at the efficient use of fuels with a minimal amount of pollutant emissions. In the specific case of the spark ignited engine, i. e., the Otto engine, a thermodynamic analysis of the engine cycle shows that overall efficiency will increase as one increases the compression ratio. Furthermore, the absolute power output increases when more mass is inducted on each intake stroke. Unfortunately, as the compression ratio is increased, the onset of a phenomenon called engine knock occurs. Knock is ruinous to the engine. Understanding the chemical basis of knock is the subject of this chapter.
KeywordsCompression Ratio Detonation Wave Flame Front Octane Number Ignition Delay Time
Unable to display preview. Download preview PDF.