Hydrogen-diesel fuel co-combustion strategies in light duty and heavy duty CI engines

The results showed NOx emissions increase with increasing H2 in the case of the light duty engine, however, in contrast, for the heavy duty engine NOx emissions were stable/reduced slightly with H2, attributable to lower in-cylinder gas temperatures during diffusion-controlled combustion. CO and particulate emissions were observed to reduce as the intake H2 was increased. For the light duty, H2 was observed to auto-ignite intermittently before diesel fuel injection had started, when the intake H2 concentration was 20% vol/vol. A similar effect was observed in the heavy duty engine at just over 8% H2 concentration.