The influence of biodiesel fuel on injection characteristics, diesel engine performance, and emission formation

The presented work focuses on numerical and experimental analyses of biodiesel fuel’s influence on the injection characteristics of a mechanically-controlled injection system, and on the operating conditions of a heavy-duty diesel engine. Addressed are mineral diesel fuel and neat biodiesel fuel made from rapeseed oil. The influence of biodiesel on mechanically controlled injection system characteristics was tested experimentally on an injection system test-bed. The injection test-bed was equipped with a glass injection chamber in order to observe the development of the fuel-spray by using a high-speed camera. The results of the experimental measurements were compared to the numerical results obtained by using our own mathematical simulation program. This program has been used to analyze the influences of different fuel properties on the injection system’s characteristics. The photos taken with a high-speed camera were compared to the simulation results obtained by using the AVL FIRE 3D CFD simulation program. This software was used to simulate the fuel-spray development during different stages of the injection process. Furthermore, the influence of biodiesel fuel on the engine operating condition of a heavy-duty diesel engine and its’ emission formation was tested experimentally on an engine test-bed, and numerically by using the AVL BOOST software. It was found out that the tested biodiesel could be used as an alternative fuel for heavy-duty diesel engines.