The Effect of Some Engine Variables on Ignition Delay and Other Combustion Phenomena in a Diesel Engine

Abstract

Measurements of ignition delay and other combustion phenomena were made on a single-cylinder, openchamber, supercharged research diesel engine. The influence of engine speed, fuel/air ratio, and air-charge pressure are reported. The results show that the elapsed time from the start of injection until illumination occurs is longer than that for pressure rise due to combustion. As expected, the measured ignition delay is decreased with increased speed. However, when a correction was made for cylinder air temperature change due to speed, the ignition delay increased with speed. Increase in the fuel/air ratio decreased the measured ignition delay. However, when corrected, the ignition delay was unaffected by fuel/air ratio. The smoke increased with engine speed and fuel/air ratio. References are given in Appendix 13. I .section of the pressure traces for the engine during motoring and firing (IS), or the combustion of a certain

Effects of fuel composition at varying air-fuel ratio on knock resistance during spark-ignition combustion

“…This effect on the in-cylinder charge temperature persists from cycle to cycle; as the in-cylinder wall temperature increases, more heat is transferred to the in-cylinder charge during intake and compression strokes. Therefore, reaction rates during the end-gas autoignition process are increased through elevated temperatures, decreasing the ignition delay time (Gauthier et al, 2004) and hence, autoignition in the end-gas occurs more easily (Bolt and Henein, 1969;Dec and Sjöberg, 2004). As a result, the operating limit of engine CR must be lowered so as to offset the additional in-cylinder temperature gained by mixture enrichment, in order to reduce the severity of the resultant knock.…”

Dizel Motorlarında Tutuşma Gecikmesini Etkileyen Faktörlerin İncelenmesi

“…Reaktif karışımların tutuşma gecikmesi süresince uğradığı değişimler ve tutuşma olayı, klasik içten yanmalı motorlarda (Bolt, 1970), yakıtların özelliklerini incelemek üzere hazırlanmış CFR (Combustion Fuels Research Corporation) motorlarında (Sahetchian, 1990;Leppard, 1991), tutuşma ve yanma olaylarının fotoğraf veya kamera tekniğiyle incelenmesine olanak sağlayan özel motorlarda (Barituad, 1994) incelenebildiği gibi akış reaktörleri (Davis, 1999;Cavaliere, 1993;Beerer, 2009), çabuk sıkıştırma makinaları (Brett, 2001;Minetti, 1995), şok tüpleri (Fieweger, 1997;Abu-Elyazeed, 2015;Hoang, 2015) ve sabit hacimli yanma odaları (Taylor, 1985;Lapuerta, 2017) gibi farklı şekillerde hazırlanmış deney sistemleriyle incelenmektedir. Bu sistemlerin herbiri farklı amaç ve deney şartlarında kullanılmıştır.…”