Optical diagnostics for the analysis of hydrogen–methane blend combustion in internal combustion engines

Abstract This chapter highlights the effect of hydrogen on the methane combustion process. The analysis of the effect of the addition of hydrogen on the methane combustion process in a small displacement optical port fuel injection spark ignition engine fueled with pure methane and two methane–hydrogen blends at 20% (v/v) (20MH 2 ) and at 40% (v/v) (40MH 2 ) of hydrogen in methane was provided. A brief introduction on the state of the art of the use of methane and hydrogen as fuel in the internal combustion engine is given. Advanced diagnostics based on optical techniques can give relevant results to complex phenomena in the internal combustion engine being nonintrusive and nonintegral measurements. The most used optical diagnostics, such as 2D digital imaging as well as ultraviolet–visible spectroscopy, for a comprehensive analysis of the combustion process with high spatial and temporal resolutions are described.