NUMERICAL SIMULATIONS OF A SIMULTANEOUS DIRECT INJECTION OF A LIQUID AND GASEOUS FUEL INTO CONSTANT VOLUME CHAMBER

Numerical simulations of a dual fuelling process by simultaneous direct injection of liquid and gaseous fuel into combustion chamber were performed. Diesel fuel and CH4 were introduced into the constant volume vessel through separate nozzles. Injection started for both fuels at the same time.Presented simulations were done using an AVL Fire code – the CFD software dedicated for engine simulations. This work was the first step in a process of modeling the full engine cycle including combustion. The aim of the study was to validate the spray model before applying it to more complex simulations.One major simplification was made to speed up the calculation process, instead of full chamber geometry only 60deg sector of the cylindrical chamber containing only two nozzles, one for gaseous fuel and one for liquid was under investigation.The simulation results were compared with literature data [1]. The images from numerical solution presenting spray droplets and CH4 concentration were compared with images made by shadowgraph technique [1].