The purpose of this work is to numerically evaluate the behavior of microscopic gas-focused liquid sheets in terms of material properties, nozzle structure and operating conditions used for experiments in spectroscopy and scattering where a short optical path is required. The numerical simulations are presented of a gas flow focusing nozzle, capable of producing a stream consisting of a sequence of perpendicular micrometre thin liquid sheets. The nozzle structure consists of a central circular capillary for delivery of the liquid and two circular capillaries that provide the focusing gas flow in a converging direction from opposite directions. High velocity impinging gas jets accelerate and form a thin elliptically shaped liquid sheet which contracts downstream and eventually forms a similar shaped sheet in the plane perpendicular to the primary sheet. The process repeats further downstream with another contraction, forming the tertiary sheet, existing now in the same plane as the primary sheet. This produces a liquid jet in form of a series of perpendicular micrometre thin liquid sheets. Three dimensional conservation equations of mass, energy and momentum for a compressible two-phase system are solved with a finite volume approach and an algebraic volume of fluid method. The influence of liquid viscosity, density, surface tension, nozzle layout variation as well as gas and liquid operating parameters on the evolution of the primary liquid sheet is elaborated. The parameter space of six flow characterizing dimensionless numbers is explored in the following ranges: Reynolds gas number 64–130, Reynolds liquid number 122–620, Weber number 23–803, ratio of liquid to gas mass flow rate 16–58, viscosity ratio 26–79, and density ratio 4807–7221. The layout of the primary sheet is given in terms of sheet thickness, width and length. The results show minor effect of dynamic viscosity, a moderate effect of density and a dominant role of the surface tension. The liquid sheet shape is sensitive to the variation of gas and liquid flow rates as well as the nozzle's structure width and the angle between the liquid delivery and the focusing gas capillaries.

这项工作的目的是在需要短光程的光谱学和散射实验中，从材料特性，喷嘴结构和用于光谱学和散射实验的操作条件的角度，对微观的气体聚焦液体薄片的行为进行数值评估。给出了气流聚焦喷嘴的数值模拟，该喷嘴能够产生由一系列垂直的微米级薄液体片组成的流。喷嘴结构由用于输送液体的中央圆形毛细管和两个圆形毛细管组成，两个毛细管在相反方向的会聚方向上提供聚焦气流。高速冲击气体喷射流加速并形成椭圆形的薄液体片，该液体片向下游收缩并最终在垂直于初级片的平面中形成相似形状的片。该过程进一步向下游重复进行另一次收缩，形成第三张薄片，该第三张薄片现在与第一张薄片存在于同一平面中。这产生了一系列垂直的微米薄液体片形式的液体射流。利用有限体积法和流体代数法求解了可压缩两相系统的质量，能量和动量的三维守恒方程。阐述了液体粘度，密度，表面张力，喷嘴布局变化以及气体和液体操作参数对一次液体薄片演变的影响。在以下范围内探索了六个流量表征的无量纲数的参数空间：雷诺气体数64–130，雷诺液体数122–620，韦伯数23–803，液体与气体的质量流量比16–58，粘度比26-79，密度比4807-7221。主要薄片的布局是根据薄片的厚度，宽度和长度给出的。结果表明，动态粘度的影响较小，密度的影响适中，表面张力起主要作用。液体薄片的形状对气体和液体流速的变化，喷嘴的结构宽度以及液体输送和聚焦气体毛细管之间的角度敏感。液体与气体的质量流量比为16-58，粘度比为26-79，密度比为4807-7221。主要薄片的布局是根据薄片的厚度，宽度和长度给出的。结果表明，动态粘度的影响较小，密度的影响适中，表面张力起主要作用。液体片的形状对气体和液体流速的变化以及喷嘴的结构宽度以及液体输送和聚焦气体毛细管之间的角度敏感。液体与气体的质量流量比为16-58，粘度比为26-79，密度比为4807-7221。主要薄片的布局是根据薄片的厚度，宽度和长度给出的。结果表明，动态粘度的影响较小，密度的影响适中，表面张力起主要作用。液体薄片的形状对气体和液体流速的变化，喷嘴的结构宽度以及液体输送和聚焦气体毛细管之间的角度敏感。