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为了研究喷孔位置对液滴发生器均匀液滴生成稳定性的影响,发展了液滴发生器工作过程的动力学特性计算模型,给出了基于声学理论的集液腔压力响应空间分布函数。考虑到部分小孔径、大长径比直流喷嘴的工作特点,在传统集中参数模型的基础上,建立了分布参数模型。随后,分析了Rayleigh模式下射流表面波色散关系的影响因素。结果表明,在特定的激励频率区间内,喷注面会产生近似圆环形状的波节结构,并随着频率的改变沿径向移动,因此液滴发生器的喷孔位置设计应当考虑喷注面的压力分布特性。与集中参数模型类似,喷嘴分布参数模型计算出的脉动流量也是随着激励频率的提高而减小,但滞后相位角保持约90°不变。分布参数与集中参数模型的适用界限要根据射流表面波的色散关系以及喷嘴长径比共同确定。
In order to study the influence of nozzle position on the formation stability of droplet homogeneously, a computational model of dynamic characteristics of droplet generator working process was developed. The spatial distribution function of pressure response of liquid collecting cavity was given based on acoustic theory. Taking into account the operating characteristics of some small aperture and large aspect ratio DC nozzles, a distributed parameter model was established based on the traditional centralized parameter model. Subsequently, the influencing factors on the dispersion of jet surface wave in Rayleigh mode are analyzed. The results show that in the specific excitation frequency range, the injection surface will produce the approximate ring-shaped nodal structure and move radially with the change of frequency. Therefore, the design of the orifice of the droplet generator should consider the injection surface Pressure distribution characteristics. Similar to the centralized parameter model, the pulsating flow rate calculated by the nozzle distribution parameter model decreases with increasing excitation frequency, but the hysteresis phase angle remains unchanged at about 90 °. The applicable limits of distribution parameter and lumped parameter model should be determined according to the dispersion relation of jet surface wave and nozzle aspect ratio.