In this paper the generation of Newtonian microdroplets in both Newtonian and non-Newtonian carrier fluids through a commercial micro T-junction under an opposed-flow configuration is analyzed experimentally. Pure deionized water and 0.2 wt% aqueous Xanthan gum solution in presence or absence of surfactant (Tween 20) have been considered as carrier fluids and the silicone oil is employed as the dispersed phase. The role of surfactant as a promoter of the generation of a droplet-based flow at the outlet of the T-junction is analyzed. Squeezing, dripping, jetting and parallel flow regimes have been generated by varying the flow rates of the dispersed and continuous phases at the inlets of the junction. A series of flow maps is presented in order to facilitate the design prediction of the droplet flow patterns generated at the outlet of the junction by varying the Capillary number and/or the inlet volumetric flow rates of Newtonian and non-Newtonian fluids. In the current paper, detailed information about the typical values of the droplet breakup distance from the center of the T- junction is demonstrated and the typical droplet length and polydispersity values are studied as a function of the inlet flow rate ratio and Capillary number.

本文通过实验分析了在逆流配置下通过商业化的微型T型结在牛顿和非牛顿载流体中产生牛顿微滴的过程。在存在或不存在表面活性剂（吐温20）的情况下，纯去离子水和0.2 wt％的黄原胶水溶液已被视为载液，而硅油则被用作分散相。分析了表面活性剂作为促进T型接头出口处基于液滴流动的促进剂的作用。通过改变结点入口处分散相和连续相的流速，产生了挤压，滴流，喷射和平行流态。提出了一系列流图，以通过改变牛顿流体和非牛顿流体的毛细数和/或入口体积流速来促进对在结的出口处产生的液滴流型的设计预测。在当前的论文中，详细说明了从T型结中心到液滴破裂距离的典型值的信息，并且研究了典型的液滴长度和多分散度值与入口流速比和毛细管数的关系。