Gas-liquid two phases flow is common in microfluidics but still needs more study. Precise but efficient controlling the droplets volumes is important for subsequent reaction or processing. In this paper, the diffuse interface method and boundary condition equations are introduced at the beginning. Then, to validate the present phase-field model, three kinds of simulation results are shown and fitted well with the experiments. It indicates that this method can be used to simulate the droplet deformation process in the T-junction. Afterwards, the details about the three kinds of droplet behaviors are presented and due to the instability of droplet breakup with tunnels, we mainly focus on the droplet with t obstruction for the steady breakup process. By analyzing the sensitivity about capillary number and static contact angle, we find that they both have great influence on the breakup process. The fitted curve under a 45 degree contact angle agree well with the experiment of Fu et al. Chem Eng Sci 66(18) 4184-4195, [9] which verifies the accuracy of simulation again. Next, we fit the relation between scaled critical droplet length and the Ca number and the static contact angle. At last, the critical neck width observed in the experiment is discussed based on the minimum surface energy principle as supplementary to improve this two-dimensional formula.

气液两相流在微流控中很常见，但仍需要更多的研究。精确而有效地控制液滴体积对于后续反应或加工非常重要。本文首先介绍了扩散界面法和边界条件方程。然后，为了验证当前的相场模型，给出了三种仿真结果，并与实验很好地吻合。这表明该方法可用于模拟T形结中的液滴变形过程。然后，详细介绍了这三种液滴的行为，由于液滴在隧道内破裂的不稳定性，我们主要针对稳定破裂过程中受t阻塞影响的液滴。通过分析关于毛细管数和静态接触角的灵敏度，我们发现它们都对分手过程有很大的影响。45度接触角下的拟合曲线与Fu等人的实验吻合得很好。Chem Eng Sci 66（18）4184-4195，[9]再次验证了模拟的准确性。接下来，我们拟合标度临界液滴长度与Ca数和静态接触角之间的关系。最后，基于最小表面能原理讨论了在实验中观察到的临界颈宽，作为改进该二维公式的补充。我们拟合了标度临界液滴长度与Ca数和静态接触角之间的关系。最后，基于最小表面能原理讨论了在实验中观察到的临界颈宽，作为改进该二维公式的补充。我们拟合了标度临界液滴长度与Ca数和静态接触角之间的关系。最后，基于最小表面能原理讨论了实验中观察到的临界颈宽，作为改进该二维公式的补充。