Analysis of the fuel spray diversity in the opposed-piston engine

Abstract

Experimental analysis of combustion in CI engines is difficult due to the very short duration of this process and the unfavourable thermodynamic conditions prevailing in the combustion chamber (high pressure and temperature). An alternative is to perform numerical calculations using the CFD method based on a defined combustion model. Such an approach was used in this paper to investigate the influence of different fuel injection configurations and different swirl ratio on selected parameters of the combustion process in the designed two -stroke opposed piston engine. The combustion chamber of the tested engine was formed of two movable surfaces of pistons. The AVL Fire software was used to perform the simulation. As a result of the calculations, the dependence of rate of heat release, burnt mass fraction, mean pressure in cylinder and heat transfer coefficient on defined calculation cases was obtained. In addition, a spatial distribution of the combustion stream of injected fuel was obtained. On the basis of the results obtained, conclusions regarding the impact of the fuel injection configuration and the swirl ratio on the obtained engine performance were presented.