Combustion And Ionization In Cat C7 Diesel Engine Operating On Ulsd And Jp8

Abstract COMBUSTION AND IONIZATION IN CAT C7 DIESEL ENGINE OPERATING ON ULSD AND JP8 By Prasad Dnyayneshwar Raut January 2016 Advisor: Dr. Naeim A. Henein Major: Mechanical Engineering Degree: Master of Science The ion current measured in internal combustion engines carries basic information about auto-ignition, combustion, performance and engine-out emissions. This investigation compares between the characteristics of ion current and combustion characteristics in a heavy duty diesel engine running on JP8 (aviation fuel used in military ground vehicles) and ULSD (conventional fuel used in commercial engines). In addition, engine cycle computer simulation is developed for engine operation on JP8. The experimental work is conducted on a 6-cylinder Caterpillar C7 military diesel engine equipped with an HEUI (Hydraulic Electronically controlled Unit Injector) and is controlled by a production ECU (Engine Control Unit). Measurements are made for cylinder gas pressure, injection command, ion current measured by a glow plug. The ion current signal has two peaks. First peak is produced by the pre-mixed combustion fraction. Second peak is produced by the mixing-diffusion controlled combustion fraction. Comparison is made between these two peaks and the corresponding peaks in the rate of heat release (RHR). Both have been found to be strongly dependent on the engine load. A correlations is developed for start of the ion current (SOIC) and the location of peak of pre-mixed combustion (LPPC). In addition a correlation is made between the start of ion current (SOIC) and the start of combustion (SOC). 3D simulation was made for the combustion of JP8 using a two-component surrogate mechanism developed at WSU for JP8 fuel. Comparison is made between simulated cylinder gas pressure and measurements