Effects of diluting the intake air of SI engine with argon inert gas on the NOx emissions and performance

The Argon inert gas is used to dilute the intake air of a spark ignition engine to decrease nitrogen oxides. A Ricardo E6 research engine was used. A test rig has been designed to admit the gas to the intake air of the engine for up to 15% of the intake air. The system could admit the inert gas and oxygen at preset amounts. The variables studied included the engine speed, Argon to inlet air ratio, and the results presented here included the combustion pressure, temperature, burned mass fraction, heat release rate, brake power, thermal efficiency, exhaust temperature, brake specific fuel consumption and emissions of CO, CO₂, NO and O₂. It was found that the addition of Argon gas to the intake air of the gasoline engine causes the nitrogen oxide to reduce effectively.