微尺度锥射流雾化模拟分析  

Numerical Analysis on Micro-scale Cone-jet Spraying

作　　者：甘云华[1,2] 张夏[1,2] 罗智斌[1,2] 

机构地区：[1]华南理工大学电力学院,广州510640 [2]广东省能源高效清洁利用重点实验室,广州510640

出　　处：《高电压技术》2015年第12期4000-4007,共8页High Voltage Engineering

基　　金：国家自然科学基金(51376066);中央高校基本科研业务费专项资金(201522083)~~

摘　　要：为合理选择微型荷电喷雾燃烧器的结构设计和工作参数,基于新设计的微型毛细管电极–环形电极–网格双电极荷电喷雾燃烧器,开展液体燃料乙醇雾化实验研究,得出了稳定的锥–射流雾化工作模式。基于该工作模式,对双电极产生的电场强度进行理论计算,采用数值模拟的方法对流场和电场的耦合场进行分析求解,运用乙醇–空气两相流水平集方法模拟乙醇的流动。在体积流量为1 m L/h、毛细管电压4.19 k V、环形电极电压1 k V时得到了稳定的锥–射流、毛细管附近场强分布和两相流的速度场。经过理论计算得出了乙醇产生雾化的最小体积流量。研究表明:轴向场强和径向场强在锥射流内部均逐渐增大,在锥射流界面达到最大值后逐渐减小。由于射流的外侧速度矢量出现漩涡并沿分界面的切面方向运动,促进了锥射流的形成。当环形电极电压一定时,高于最小体积流量的乙醇在适合的毛细管电压下可得到稳定的锥射流。In order to choose the structural design and working parameters of electrostatic spraying combustor reasonably, some experiments of ethanol spraying were carried out and a stable cone-jet mode was obtained based on the new double electrode combustor mainly consisting of a capillary, a ring electrode, and a stainless steel grid. Moreover, the electric field intensity distribution produced by the new double electrode was calculated theoretically. The coupled field of the flow field and electric field was calculated using numerical analysis method. The ethanol-air two-phase flow level set method was used to simulate the flow of ethanol. The stable cone-jet, the electric field intensity distribution near the ca- pillary, and the velocity field of two-phase flow were obtained with the flow rate of 1 mL/h, the capillary voltage of 4.19 kV, and the ring electrode of 1 kV. The minimum flow rate which could form a cone-jet was calculated theoretically. The results show that axial and radial electric field intensity will increase gradually in the internal of the cone-jet, reach the maximum at the interface, and then gradually decrease in the region near to the capillary. The circulation of the velocity vector is found outside the jet-flow, and the flow moves along the tangential direction, which promotes the formation of cone jet. At a certain ring electrode voltage, a stable cone-jet mode will appear when the flow rate of ethanol reaches a minimum value and a suitable voltage is put on the capillary.

关 键 词：微型燃烧器 荷电喷雾 双电极 水平集方法 锥-射流模式 场强分布 速度场 

分 类 号：TK16[动力工程及工程热物理—热能工程]