In the present study, an integrated micro-ejector was proposed to provide a mixture of n-butane and air for micro-combustors. The effects of fuel jet velocity and geometrical parameters of the ejector on the entrainment ratio were numerically investigated and theoretically analyzed. The results show that the incoming air mixes with the fuel jet flow through two routes. The entrainment ratio increases with an increasing fuel jet velocity due to the increased magnitude of negative pressure. Moreover, increasing the nozzle diameter leads to a sharp decrease in the entrainment ratio. However, the entrainment ratio can be drastically augmented by increasing the diameter of the mixing section. In addition, an increase in the length of mixing section will slightly decrease the entrainment ratio of the ejector. Furthermore, increasing the total area of air inlets gives rise to a drastic decrease in the entrainment ratio. These variation tendencies have a close relationship with the negative pressure contours. The findings of this study provide a guidance to the optimal design of this kind of micro-ejectors.

在本研究中，提出了一种集成的微型喷射器，为微型燃烧器提供正丁烷和空气的混合物。对燃料喷射速度和喷射器的几何参数对夹带率的影响进行了数值研究和理论分析。结果表明，进入的空气与燃料喷射流通过两条路径混合。由于负压大小的增加，夹带率随着燃料喷射速度的增加而增加。此外，增加喷嘴直径导致夹带率急剧下降。但是，可以通过增加混合部分的直径来大幅度提高夹带率。另外，增加混合部分的长度将稍微降低喷射器的夹带率。此外，增加进气口的总面积会导致夹带率的急剧下降。这些变化趋势与负压轮廓密切相关。这项研究的结果为这种微喷射器的优化设计提供了指导。