In this paper the rate of convergence, speed of execution and symplectic properties of the time-integrators Leap-Frog (LF2), fourth order Runge-Kutta(RK4) and Crank-Nicholson (CN2) have been studied. This was done by solving the one-dimensional model for a particle in a box (Dirichlet-conditions). The results show that RK4 is the fastest in achieving higher tolerances, while CN2 is the fastest in achieving lower tolerances. Fourth order corrections of LF (LF4)and CN (CN4) were also studied, though these showed no improvements overLF2 and CN2. All methods were shown to exhibit symplectic behavior..

A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.