| 黄晓冬，袁银男，邓海鹏，王宇鹏.针阀升程对乙醇柴油的空化现象及近场喷雾特性的影响[J].内燃机工程,2019,40(2):22-28. |
| 针阀升程对乙醇柴油的空化现象及近场喷雾特性的影响 |
| Experimental Investigation into Effect of Needle Lift on Cavitation Characteristics and Near-Field Spray of Ethanol-Diesel |
| DOI：10.13949/j.cnki.nrjgc.2019.02.004 |
| 关键词:空化 近场喷雾 针阀升程 可视化试验 |
| Key Words:cavitation near-field spray needle lift visual experiment |
| 基金项目:“十二五”国家科技支撑计划项目（2014BAG11B00） |
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| 摘要:基于等比例放大透明喷嘴搭建可视化试验台，以乙醇柴油为流动介质，通过控制燃油喷射压力改变孔内燃油流动速度，对比研究了不同燃油流速下3种针阀升程（3 mm、6 mm和8 mm）所对应的喷嘴孔内空化现象及近场喷雾形态。试验发现：喷嘴孔内空化现象随燃油流速升高依次历经无空化阶段、空化阶段(初生-发展-超空化)和柱塞流阶段；同等燃油流速下针阀升程越小，则喷嘴孔内越易发生空化，且空化现象更为强烈。喷孔流量系数随燃油流速升高呈先缓慢增大后急剧减小的变化趋势；同等燃油流速下针阀升程越大，则喷孔流量系数越大。近场喷雾锥角随燃油流速升高呈先增后减的变化趋势；在柱塞流发生之前，同等燃油流速下针阀升程越小，则近场喷雾锥角越大，且喷雾锥角峰值对应的燃油流速越小。 |
| Abstract:A transparent scaled-up cylindrical nozzle was used to set up a visible test bench, and the cavitation characteristics and near-field spray morphology of ethanol-diesel in nozzle at different needle lifts of3 mm, 6 mm and 8 mm were explored at different fuel flow velocities that obtained by adjusting injection pressure. The experimental results indicate that with the increase of fuel flow velocity the cavitation in nozzle experiences non-cavitation, cavitation(incipience, development, super-cavitation) and hydraulic flip. At the same fuel flow velocity, a smaller needle lift is more prone to produce cavitaion and the cavitaion is more intense. With the increase of fuel flow velocity, the nozzle discharge coefficient changes from a gentle rise to a sudden decline. The larger the needle lift is, the greater the discharge coefficient is at the same fuel flow velocity. And the near-field spray cone angle increases first and then decreases with the increase of fuel flow velocity. A smaller needle lift has a larger near-field spray cone angle at the same fuel flow velocity before the hydraulic flip, and the fuel flow velocity at which the maximum near-field spray cone angle appears is lower. |
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