Effects of injection parameters on combustion characteristics of n-heptane spray and nitrogen oxides NOx concentration under the supercharged conditions were investigated using a constant volume vessel. History of NOx formation during combustion was clarified using a total gas-sampling device. The results show that increasing ambient pressure enhances the spray combustion and offers higher heat release rate. Elevating ambient pressure also promotes NOx formation. In addition, NOx formation is significantly affected by injection parameters.
