| 摘要:探讨270 MPa超高喷射压力、70 kg/m3高环境密度下柴油近场喷雾与喷油率映射相关性。应用长距显微法拍摄整个喷射过程中的喷雾发展过程，利用小野测器（FJ-8000）测试喷射特性。通过比较分析喷雾特性与喷油率变化规律，发现喷雾发展过程可以由膨胀、稳定和收缩3个阶段来表征，且与三段式喷油率过程呈一一映射对应关系。试验结果表明，近场喷雾动态发展能够定性地描述喷油率变化，即：在喷射开始后，喷雾开始膨胀，随后逐步进入稳定阶段；在喷射结束前，较小喷孔直径的喷油器喷雾逐渐收缩变窄。需要特别指出的是，对于较大喷孔直径喷油器，针阀落座导致喷雾结束时尾部产生剧烈变化从而使喷雾产生相对不稳定和不对称形状。 |
| 关键词: 超高压喷射 近场喷雾 喷油率 喷雾宽度 |
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| Correlation Between Diesel Near-Field Spray and Fuel Injection Rate Mapping Under Ultra-High Injection Pressure |
| YOU Yue |
| Shanghai Marine Diesel Engine Research Institute，Shanghai 201108，China |
| Abstract:The correlation between diesel near-field spray and fuel injection rate mapping at the ultra-high injection pressure of 270 MPa and the high ambient density of 70 kg/m3 is investigated.The whole spray development process was visualized by long-distance microscopy，and the injection rates were tested by ONO SOKKI FJ8000.By comparing and analyzing the spray characteristics and the change law of fuel injection rate，it is found that the spray development process can be characterized by three stages：expansion，stability and contraction，and it has a one-to-one mapping correspondence relationship with the three-stage injection rate process.The test results show that the dynamic development of near-field spray can qualitatively describe the change of fuel injection rate，that is：the spray begins to expand after start of injection，and gradually enters a stable stage；before the end of the injection，the spray of the injector with the smaller orifice diameter gradually shrinks and narrows.However，for larger nozzle diameter injectors，the needle seat can result in a dramatic change in the spray tail，leading to relative instability and an asymmetric spray shape. |
| Key words: ultra-high injection near-field spray injection rate spray width |
