Simulation-based fuel testing for diesel engine combustion and performance mapping
M Pasternak, F Mauss, F Lange, S Schmerbeck, E Heinl, A Mork
Abstract
The characteristics of different hydrocarbon fuels were simulated under Diesel engine conditions. n-Heptane and its blends with iso-octane, and toluene have been considered as surrogates of a real Diesel fuel. A direct injection stochastic reactor model (DI-SRM) was used as a numerical tool. Simulations covered a broad range of operating conditions defined by variation of pressure (p) and temperature (T) at the inlet valve closure (IVC), and different EGR fractions. The fuel-air equivalence ratio (φ) was kept constant for each fuel. The emission trends of the fuel together with the engine output performance were analysed in form of 2D maps. The maps relate a given engine parameter with p, T, and EGR variations. Such simulations allow comparing engine output performance and engine out emissions with respect to the applied fuel blend. Furthermore, the influence of changes of initial p and T on the chemical kinetic processes for each considered fuel is presented.