Effect of hydrogen blending on the combustion performance, emission, and cycle-to-cycle variation characteristics of a single-cylinder GDI spark ignition dual-fuel engine

The effect of hydrogen addition on combustion, performance, emission and cyclic variation under different hydrogen flow rates (2, 5, 8, 11, and 14 LPM) were investigated based on a SI engine with hydrogen port induction and gasoline direct injection. The in-cylinder pressure increases by 52.04% with an 8LPM of hydrogen flow rate. The rate of pressure rise and heat release from the hydrogen-gasoline mixture combustion are more concentrated and 95.53% increase in the engine torque. For the specified hydrogen flow rate, brake specific energy consumption was reduced by 92.27% and brake thermal efficiency increased by 25%. Moreover, CO emission was improved after hydrogen addition under all operating conditions. CO2 and NOX emissions were continuously increased with hydrogen addition. The cyclic variation was increased with the increase in the hydrogen flow rate and reduced with the increase in gasoline injection quantity. © 2023