A Computational Study of Methanol Combustion Engine Assisted by Glow Plug

This work explores the methanol compression ignition combustion assisted with a glow plug. The effects of the glow plug position, spray umbrella angle, the relative angle between the glow plug and jet trajectory, and the injection strategy on the engine performance were evaluated. Of these parameters, the relative angle between the glow plug and jet was found to be the dominant factor affecting the ignition and combustion heat release. At each position of the glow plug, the optimum relative angle differed due to the complex flow and air-fuel mixing within the combustion chamber. Among the four representative regions, the east region yielded slightly higher thermal efficiency and lower combustion loss. Compared to the single injection strategy, the split injection strategy was more effective in promoting the ignition process. The engine performance exhibited a high sensitivity to the pilot and main injection timings. Furthermore, the slightly narrower spray umbrella angle yielded better fuel economy because less fuel was trapped within the squish region, leading to faster flame propagation and less unburned fuel.