This study focuses on the generation of bubbles in a step-emulsification microdevice via a two-angle photography method. It's found that the bubble generation mechanism is controlled by the interfacial tension, below a critical capillary number; while controlled by viscous force, inertial force and the disturbance induced by the bubble swarm, above the critical capillary number. From the two-angle photography method, a model is established for predicting the bubble size, by taking into account of the dynamic contact angle between gas-liquid interface and wall, and the hydrodynamic feedback of the cavity on bubble formation via the quantification of resistance by the volume fraction of gas in the cavity.

这项研究的重点是通过两角度照相法在逐步乳化微设备中产生气泡。发现气泡的产生机理是由界面张力控制的，低于临界毛细管数。在临界毛细管数以上时，由粘性力，惯性力和气泡群引起的扰动控制。从两角度照相法出发，通过考虑气液界面与壁之间的动态接触角以及通过对阻力的定量确定腔体对气泡形成的流体动力反馈，来建立预测气泡尺寸的模型。由空腔中气体的体积分数得出。