喷油嘴喷孔结构参数对甲醇燃料喷射流场影响的数值模拟
Effect of Nozzle Nozzle Structural Parameters on Flow Field of Methanol Fuel Injection

针对甲醇燃料不同于汽油的物化特性以及甲醇发动机冷启动困难等问题，以甲醇发动机喷油嘴喷孔为研究对象，采用Fluent软件的气液两相VOF湍流模型对喷嘴进行了数值模拟。研究发现了喷嘴入口处曲率半径变化以及喷嘴倒锥角度变化对喷嘴流量和雾化效果有一定的影响。结果表明：在压力不变的条件下，随着入口处曲率半径增大负压层的厚度逐渐变薄，喷孔内部气相体积分数减小，质量流量增大，雾化性能变差，但是喷孔的流速随着曲率半径的增大而增加；增大喷孔的倒锥角，喷嘴出口处的流速及质量流量均减小，但是负压层变厚有利于甲醇燃料的雾化。
According to the different physical and chemical properties of methanol fuel from gasoline, and the difficulty of cold start of methanol engine, we choose the nozzle of methanol engine as the research object. The gas-liquid two-phase VOF turbulence model in Fluent software is used to simulate the nozzle flow. The study finds that the fillet changes in the inlet nozzle and inverted cone angle changes of nozzle have certain influence on nozzle flow field. The results show that under the condition of constant pressure, the thickness of the negative pressure layer decreases with the increase of the radius of curvature at the entrance, the volume fraction of the gas phase decreases and the atomization performance decreases. With the increase of nozzle curvature radius, the flow rate increases. Increasing the inverted cone angle of the nozzle hole, the flow rate at the nozzle outlet is reduced, the mass flow rate is reduced, but the thickening of the negative pressure layer is favorable for the atomization of the methanol fuel