Fuel and OH radical distribution measurements in a SI engine using planar laser induced fluorescence

There are two important factors in the combustion chamber of an engine to improve engine performance and emissions. One is air-fuel mixture preparation related to flow field and the other combustion flames. Improper mixture preparation causes poor combustion and bad emissions, which then lead to unstable engine operation. To study these phenomena, we have applied laser induced fluorescence to an optical accessible engine. Fuel concentration images are acquired during intake and compression processes. Also, during combustion the OH radical is excited by KrF excimer laser on Q/sub 1/(11) and P/sub 2/(8) line.