喷射策略对柴油转子发动机缸内燃烧过程的影响

Effect of Injection strategy on Combustion Progress in Diesel Rotary Engine

中文关键词: 内燃机  转子发动机  柴油  喷射时刻  二次喷射

英文关键词: IC engine  rotary engine  diesel  fuel injection timings  second fuel injection

中文摘要:

      针对直喷式柴油转子发动机缸内工作过程,基于Fluent软件建立了耦合正庚烷简化机理的二维计算模型,并利用文献数据验证了模型的可靠性。在此基础上,设定喷射持续期不变,对比分析了单次或二次喷油时喷射时刻对燃烧过程的影响。研究结果表明：单次喷射时,缸内压力和缸内温度随喷射时刻的推迟而逐渐提高；喷油提前角为40°CA时CO生成量较高而NO生成量最低。二次喷射时,设置预喷时刻为-40°CA,随着主喷时刻的推迟缸内压力变化不大,CO生成量逐渐降低；当预喷时刻为-40°CA,主喷时刻-8°CA时,与单次喷射时刻为-40°CA相比,保持了较高的缸内压力,CO生成量降低了25%以上,NO生成量有所升高。

英文摘要:

      Based on the Fluent software, a two-dimensional calculation model of a direct injection diesel rotary engine coupled with a reduced reaction mechanism of n-heptane was established. The reliability of the model was verified by literature data. On the basis of this, the injection duration was set unchanged, the influence of single injection timing and second injection timing on the combustion process was compared and studied. The results show that the cylinder pressure and the cylinder temperature were increasing with the injection timing delay, the CO generation was higher and the NO generation was the lowest when the injection advance angle was 40°CA.When the pre-injection timing was -40°CA and the main injection timing was -8°CA, a high in-cylinder pressure was maintained, the CO generation was reduced by more than 25% and the NO generation was increased compared to the single injection timing of -40°CA.