标题： 自润湿液滴与液层相互作用的聚并和断开过程的研究 显示英文标题

标题： Investigation of coalescence and pinch-off processes of a self-rewetting drop interacting with a liquid layer

摘要： 自润湿流体（SRFs），如长链水溶性醇类，是一类表面张力异常地与温度二次方相关的特殊液体，导致热毛细流动与普通流体（NFs）显著不同。 本研究重点是研究在非均匀加热条件下，SRF液滴与液层相互作用的行为。 在这方面，我们采用了一种基于中心矩的格子玻尔兹曼方法，结合轴对称形式的相场模型，以高效捕捉三维效应。 我们研究了SRFs中的合并和断裂过程，并将其与NFs进行比较。 我们的模拟结果显示，SRFs比NFs更早发生断裂。 我们还观察到，增加Ohnesorge数Oh会抑制断裂过程，突显了粘性力的相对作用，该作用受重力效应或Bond数Bo的调节。 此外，我们探讨了改变表面张力对温度的无量纲线性和二次敏感系数M1和M2，以及无量纲热通量Q如何影响合并/断裂行为。 有趣的是，与NFs的行为相反，在SRFs中，增加M2或Q会减少断裂所需的时间，并扩大在Oh-Bo参数图中发生断裂的区域，与未加热情况相比。 这些差异被证明是由于界面上热毛细力的变化所致。 总体而言，我们发现，在非均匀加热下，SRFs在更广泛的条件下比NFs增强了断裂过程。 显示英文摘要

摘要： Self-rewetting fluids (SRFs), such as long-chain aqueous alcohols, are a special class of liquids with surface tension that is anomalously dependent quadratically on temperature, resulting in thermocapillary flows that differ significantly from those in normal fluids (NFs). This study focuses on investigating the behavior of SRF drops interacting with a liquid layer under nonuniform heating conditions. In this regard, we employ a robust central moment-based lattice Boltzmann method with a phase-field model expressed in an axisymmetric formulation to capture three-dimensional effects efficiently. We investigate the coalescence and pinch-off processes in SRFs and compare them to those in NFs. Our simulations reveal that SRFs undergo pinch-off earlier than NFs. We also observe that increasing the Ohnesorge number Oh suppresses the pinch-off process, highlighting the relative role of viscous forces, which is modulated by gravity effects or the Bond number Bo. Furthermore, we explore how varying the dimensionless linear and quadratic sensitivity coefficients of surface tension on temperature, M1 and M2, respectively, and the dimensionless heat flux Q influence the coalescence/pinch-off behavior. Interestingly, contrary to the behavior in NFs, in SRFs increasing M2, or Q reduces the time required to pinch-off and widens the region in the Oh-Bo regime map where pinch-off occurs, when compared to the unheated cases. These differences are shown to be due to the variations in the thermocapillary forces on the interface. Overall, we find that under nonuniform heating, the SRFs enhance the pinch-off process compared to NFs across a wider range of conditions.