Investigating Diesel Engine Combustion by Means of a Timed Sampling Valve

The design and application of a high speed, timed, sampling valve for the extraction of gas samples, at a variety of points and times, from the combustion chamber of a medium speed diesel engine is described.

The valve was traversed radially into the combustion chamber and combined with rotation of the central fuel injector gave sampling at sixteen points relative to the fuel spray. For any given sample the valve opened and closed at the same time each cycle. Samples were analysed and the levels of carbon monoxide, carbon dioxide and nitric oxide were recorded for the complete combustion process.