Abstract
For better understanding of in-cylinder combustion characteristics in a direct injection DME engine, radicals were observed using the spectroscopic method. In this experiment, after passing through a spectroscope emission intensity was measured by photomultiplier. Two strong emission intensities were found in 427nm and 431.4nm. Emission intensity of 427nm became strong from the early stage to middle stage of diffusion combustion period. Emission intensity of 431.4nm became strong from the middle stage to second half of diffusion combustion period. The line spectra where strong emission intensities were observed in this DME engine shift from those that are obtained on the burner flame.
