Combustion Visualization in Commercial Engines Operating with Diesel-Biodiesel Blend

The Brazilian government encourages the use of renewable fuels in diesel engines through resolutions that define the mandatory addition of biodiesel to automotive diesel oil. The use of biodiesel will reach 15% by 2026. Due to this change in the physicochemical characteristics of commercial fuel, there is a need to deepen studies regarding the combustion process and the effects of this change on engine performance and emissions. With technological advancements, one of the viable techniques for this purpose is high-speed imaging to assess combustion within the cylinder. This paper presents the methodology for constructing a system that allows high-speed imaging, using a high-speed camera, of the combustion process of an MWM 229/4 engine. Other studies published in this area typically involve capturing images inside the cylinder once per cycle and advancing the angular position of capture each cycle. This paper proposes a more refined method, where images are acquired every 2.5°CA, allowing for the observation of a sequence of images from the same cycle. As a result, the images captured in one of the cylinders are presented, in which one can observe the evolution of combustion synchronized with the in-cylinder pressure curve.