Direct injection diesel engine combustion analysis using a new high-speed spectral infrared imaging method and KIVA-II computer code

In this work we investigate in-cylinder events of a direct injection diesel engine by using a new high-speed spectral infrared imaging system. The imaging system which was developed at the Rutgers University IC Engine Laboratory employs a two-color IR imaging arrangement. The imaging system was set up with the single cylinder DI diesel engine which was equipped with optical access converted from one of two intake valves. The valve train system was also modified to accommodate the change of the valve system.; The characteristics of the two-color method were investigated by the graph method and certified by analytical verification. The flame temperature and KL distribution was analyzed from the measured IR images by using the two-color method.; A computational prediction was attempted by using the KIVA-II computer program which was developed by the Los Alamos National Laboratory. Also, the sensitivity of parameters which affect the penetration of flame, such as grid size, swirl, spray parcel, and distribution of fuel drops, was studied.; The first ever high speed two-color infrared images of the in-cylinder process in a DI diesel engine were obtained. Among the significant observations was that the temperature was relatively low along the axis of the projected fuel spray view at the early part of combustion.; In real measurement, some data exhibited that {dollar}Tsb{lcub}a1{rcub}{dollar}, the blackbody equivalent temperature of the flame at short wavelength {dollar}lambdasb1{dollar}, was actually smaller than {dollar}Tsb{lcub}a2{rcub}{dollar} of long wavelength {dollar}lambdasb2{dollar}, which is in conflict with the characteristics of the two-color method, in other words, there is no solution in this domain for the temperature and KL calculation.; The first flame was advanced and flame temperature increased according to the increase of engine load. The first flame and the start of high intensity combustion were almost the same as the advanced crank angle of the fuel injection time. However, the end of the high intensity combustion period was quite shortened.; The results obtained from our computational analysis and experimental measurement do not compare each other, including some key flame characteristics.