IR Imaging of Combustion Process in a Transparent Euro5 Diesel Engine fed with Biofuels

In the present paper, infrared (IR) measurements were performed in order to study the behavior of biofuels combustion in a transparent Euro 5 diesel engine operating in premixed mode. Commercial diesel fuel (REF) Gas To Liquid (GTL) and Rapeseed Methyl Ester (RME) biofuels has been used. An elongated single cylinder engine equipped with the multi-cylinder head of commercial passenger car and with common rail (CR) injection system was used. A sapphire window was set in the bottom of the combustion chamber, and a sapphire ring was placed in the upper part of the cylinder. Measurements were carried out through both accesses by a high-speed infrared (IR) digital imaging system obtaining information that was difficult to achieve by the conventional UV- visible cameras. IR camera was able to detect the emitted light in the wavelength range 1.5-5 ?m. IR measurements showed the ability to determine temporal and spatial distribution of fuel during evaporation phase and evaluate the late combustion process evolution, so resulting in a good instrument for the analysis of the behavior of alternative fuels in a conventional diesel engine.