Date of Award
Mechanical, Automotive, and Materials Engineering
With increasingly stringent emission standards it is necessary to develop new methods of emission reduction in the internal combustion engine. With the addition of fuel efficiency requirements being added by 2020 the diesel engine is an attractive option for heavy duty applications, due to its greater thermal efficiency compared to its gasoline counterpart. However, diesel engines require a combination of in-cylinder emission reduction and after-treatment devices in order to meet the current emission regulations, but with the implementation of these in-cylinder emission reducing strategies there may be an increase in cyclic variation of combustion. This cyclic variation can cause issues as extreme as misfire, or catastrophic failure from excessive cylinder pressure, or lesser issues such as increased noise or periodic decreases in efficiency. This study investigated the combustion stability of diesel single shot combustion and ethanol port fuel injection and diesel direct injection combustion. The effect of exhaust gas recirculation and combustion phasing on the cycle-to-cycle variation of diesel single shot combustion, and the effect of exhaust gas recirculation and diesel – ethanol ratio on the combustion stability of ethanol port fuel injection with diesel direction is reported. It was found that exhaust gas recirculation did not cause a significant increase in the COVIMEP for the majority of the tests carried out, the exceptions were for tests with over 95% of the fuel energy provided by ethanol port injection. The standard deviation of CA50 increased with the application of EGR, retarding of combustion phasing for diesel single shot combustion, and diesel – ethanol dual fuel combustion.
Bryden, Geraint Andrew Howard, "INVESTIGATION ON CYCLIC VARIATION OF LOW TEMPERATURE COMBUSTION SRATEGIES" (2018). Electronic Theses and Dissertations. 7351.