The first and second law analyses of a port-injected, spark ignition engine fuelled with compressed natural gas

Availability changes with crank angle at the optimum engine operating point of 4000 rpm and WOT for CNG fuelling, CNG and gasoline engine operations at optimal engine conditions with the equivalence ratio Ö = 1.1, distribution of fuel availability of CNG and gasoline fuelled engine at equivalence ratio of Ö = 1.1, entropy-temperature diagram for the engine optimal operating point and CNG fuelling, specific availability and internal energy vs. temperature for optimal CNG operation at WOT, 4000 rpm, pressure-volume diagram for simulated (fuel/air cycle and air cycle) results and experimental data at WOT, 4000 rpm for CNG fueled V8 engine are presented in the paper.