Abstract
Pistons of the engine for JR diesel railcars often suffer damage caused by the fusion of piston head due to the high temperature of combustion flames. The authors have proposed an investigation method to measure the spectrum on diesel flames using optical fibers, and estimated the flame temperature from the data obtained by a simplified procedure. They applied this method to the practical engine to find solutions to the above mentioned problems. As a result, the process of the piston damage was made clear, and an adequate trouble-shooting measure was established.
