Engine Diagnostics Using Laser Induced Fluorescence Signals Collected Through an Endoscopic Detection System

In this paper an alternative method for collecting laser induced fluorescence (LIF) signals from engines with limited optical access is presented. An endoscopic detection system has been used for LIF visualisation of both gaseous and liquid fluids in a DISI-engine. The use of an endoscope made it possible to monitor parts of the combustion chamber that could not be accessed through the piston with conventional optics.

Brief investigations of the signal collection efficiency have been performed on the endoscopic system as well as on a system based upon conventional optics.

The technique shows promising results and the use of endoscopic detection systems should be considered as a complement to using advance design quarts piston crowns for conventional detection through the piston.