The combustion vessel is a pressure vessel with optical access which can withstand the pressures and temperatures that occur in combustion and internal combustion (IC) engines. Data will be acquired for the comprehensive study of transport phenomena and thermo-chemical processes including combustion above super-critical conditions of many liquid fuels. Various issues will be examined using this laboratory, such as research with droplets and sprays, flammability and safety, spark-ignited and diesel fuel-air mixing and combustion, as well as bio- and alternative fuels mixing and combustion. Additionally, numerous optical methods will characterize droplet, spray, vaporization and soot. The results of these studies will be used to improve industrial applications involving these processes, and to help develop more efficient combustion processes.
General Motors Single Cylinder Test Engine
Biodiesel Combustion Analysis
Biodiesel is a prospective renewable fuel for diesel engines with the potential to reduce engine exhaust emissions. As the application of diesel engines continues to increase, and so also has the complexity of both these engines and aftertreatment systems to meet lower emissions standards around the world. In the US, both the light duty vehicle Tier II and 2010 on-road heavy duty governmental regulations require greater reductions in emissions, particularly NOX. As a result, the diesel engine and diesel af-tertreatment systems are highly tuned mechanisms that are sensitive to the effects of changing fuel characteristics. Concurrently increases in fuel prices and concerns about atmospheric CO2 con-centrations are leading to the exploration of renew-able and lower net CO2 emission fuels such as ethanol and biodiesel. This investigation focuses on the PM - NOX emissions tradeoff and how the use of biodiesel fuel impacts this relationship.
Tests were carried out on a 1.9 Liter HSDI turbo diesel engine fueled with 15 ppm low sulfur diesel, a B20 fuel and a B100 fuel. In the experiments engine control parameters including fuel injection timing and EGR were varied to determine the ef-fects of the selected fuels.
The results show improvements in PM emissions with a slight increase in NOX emissions. However, as the biodiesel fuels have a reduced ignition de-lay, thus shifting the start of combustion (SOC), additional testing was conducted holding SOC con-stant to eliminate the effects of combustion timing on the PM - NOX tradeoff.
