Laser diagnostic analysis of no formation in a direct injection diesel engine with pump-line-nozzle and common rail injection systems

Laser-induced fluorescence (LIF) imaging was applied to investigate NO formation in a directly injected diesel engine with realistic combustion chamber geometry. The technique, which uses KrF excimer laser excitation, was preciously successfully applied in gasoline engines. Influences of interfering species depending on the spectral range used for LIF detection was investigated by spectrally resolved LIF detection. Laser and signal attenuation were assessed in separate experiments using spectrally resolved O-2-LIF detection with the same optical path as in the imaging measurements. The in-cylinder NO concentration was compared for different injection systems and operating conditions.