Thermal efficiency optimization of a single cylinder gasoline engine based on active jet ignition

Jet ignition is a promising technology for improving the thermal efficiency of internal combustion engines (ICEs). To achieve the highest possible thermal efficiency, the jet ignition strategy was studied on a gasoline engine. Firstly, a combustion process featuring three stages of heat release, based on uniformly distributed jet ignition, was proposed. Next, the geometric structure of an active jet igniter was optimized using numerical simulations. Using the designed jet igniter, the effects of engine operating conditions were explored, including auxiliary fuel injection in the jet igniter, gross excess air ratio, and engine load and speed, with the goal of maximizing thermal efficiency. A highest indicated thermal efficiency of 50.3% was achieved, verifying the effectiveness of the proposed combustion strategy with uniformly distributed jet ignition. This study provides a technical reference for developing high-efficiency gasoline engines using jet ignition.