| 摘要:基于定容弹实验平台，通过纹影法和双色法，探究矩型、斜坡型及靴型等3种喷油规律对柴油喷雾宏观特性及火焰碳烟场的影响机制。研究发现：3种喷油规律的贯穿距差异小于5%，峰值喷油速率是最大贯穿距的主要因素；斜坡型与靴型的远场锥角较矩型分别扩大30.15%和11.29%，这是由于喷油速率增长加速度提高导致喷雾径向扩散增强。将喷油量和喷雾体积相结合，得到喷雾的平均当量比，可以在一定程度上反映出喷雾的混合质量。结果表明，靴型和斜坡型平均当量比较矩型降低约40%，表明通过改变喷雾速率形状，可以显著改善油气混合均匀性，有利于抑制局部高温和未燃物生成。经过对火焰的KL碳烟因子的分析发现，靴型和斜坡型碳烟KL因子较矩型分别降低8.5%和5.9%。本研究为优化柴油机喷油策略以提升燃烧效率及降低碳烟排放提供了实验依据。 |
| 关键词: 可变喷油规律 纹影法 双色法 KL碳烟因子 |
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| Effects of Variable Injection Characteristics on Spray and Flame Soot Fields |
| WANG Keao,SHEN Kun,WEI Daijun,QIAO Yanyu,CHENG Qiang,DONG Quan |
| College of Power and Energy Engineering Department，Harbin Engineering University， Harbin 150001， China |
| Abstract:The effects of rectangular，ramp-shaped，and boot-shaped injection rate profiles on diesel spray macroscopic characteristics and flame soot fields are investigated using a constant-volume bomb experimental platform combined with schlieren method and two-color pyrometry.Key findings include：the penetration differences among the three injection profiles were less than 5%，with peak injection rate being the dominant factor for maximum penetration distance；ramp-shaped and boot-shaped profiles increased far-field spray cone angles by 30.15% and 11.29% respectively compared to the rectangular profile，which was due to the enhanced spray radial dispersion caused by enhancement stems from increment in injection rate acceleration.By combining injected fuel mass and spray volume， the average equivalence ratio was calculated to reflect the mixture quality of spray.The results showed that boot-shaped and ramp-shaped profiles reduced average equivalence ratio by approximately 40% compared to rectangular profile，demonstrating that modifying injection rate shapes significantly improved air-fuel mixing uniformity，thereby suppressing local high-temperature zones and unburned emissions.Analysis of flame KL soot factors revealed reductions of 8.5% and 5.9% for boot-shaped and ramp-shaped profiles respectively compared to rectangular profile. This research provides experimental evidence for optimizing diesel injection strategies to enhance combustion efficiency and reduce soot emissions. |
| Key words: variable injection characteristic schlieren method two-color pyrometry KL soot factor |
