关键词: 正丁醇；缸内直喷；喷油正时；燃烧；排放

Abstract: To improve the suboptimal air-fuel mixture quality found when using n-Butanol fuel in direct injection engines, this study uses a specific engine model as an example and establishes a single-cylinder physical model with 3D computational fluid dynamics (CFD) software, based on the engine’s operational process. The study aims to analyze how various injection timings influence engine performance. The investigation reveals that advancing the injection timing, compared to delayed injection, provides more time for the air and fuel to mix, resulting in a better air-fuel mixture quality. Improved mixture quality leads to increased in-cylinder pressure and decreased emissions of CO, soot, and HC. However, it is imperative to note that this adjustment engenders an increment in the emission of NOX.

Key words: N-Butanol; In-cylinder direct injection; Injection timing; Combustion; Emission