The stability of thermocapillary flow in a liquid bridge made from 5cSt silicone oil (Pr = 68) is computed numerically. To improve the numerical model as compared to the standard approach, we consider the flow in the liquid bridge fully coupled to the flow in the ambient gas, temperature-dependent material parameters, and a dynamically deforming liquid–gas interface. We address the full two-phase-flow problem of interest for the space experiment JEREMI and investigate the effect of a steady axisymmetric coaxial gas flow which is imposed at the inlet of the annular gap between the liquid bridge and the outer confining cylinder. Under zero-gravity the flow is primarily driven by the imposed temperature gradient with viscous stresses from the gas phase being small. However, the heat transfer between liquid and the gas, and thus the temperature fields are strongly affected by the forced flow in the gas phase. As a result the stability of the steady axisymmetric flow depends sensitively on the flow direction and the temperature of the gas. If the temperature of the gas is identical to that of the support rod of the liquid bridge a gas stream opposing the thermocapillary stresses strongly destabilizes the basic flow. In a co-flow configuration the basic state is stabilized. Curves of neutral Reynolds numbers as functions of the strength of the annular gas flow are discussed for two aspect ratios of the liquid bridge.

数值计算了由5cSt硅油（Pr = 68）制成的液桥中热毛细管流动的稳定性。与标准方法相比，为了改进数值模型，我们认为液桥中的流量与环境气体中的流量，温度相关的材料参数以及动态变形的液-气界面完全耦合。我们解决了空间实验JEREMI感兴趣的全部两相流问题，并研究了稳定的轴对称同轴气流的影响，该气流施加在液桥和外部约束圆柱体之间的环形间隙的入口处。在零重力下，流量主要由施加的温度梯度驱动，气相中的粘性应力较小。但是，液体和气体之间的热传递 因此，温度场受到气相强制流动的强烈影响。结果，稳定的轴对称流的稳定性敏感地取决于气体的流向和温度。如果气体的温度与液桥的支撑杆的温度相同，则与热毛细管应力相反的气流会严重破坏基本流量的稳定性。在顺流配置中，基本状态是稳定的。对于液桥的两个纵横比，讨论了中性雷诺数随环形气流强度变化的曲线。如果气体的温度与液桥的支撑杆的温度相同，则与热毛细管应力相反的气流会严重破坏基本流量的稳定性。在顺流配置中，基本状态是稳定的。对于液桥的两个纵横比，讨论了中性雷诺数随环形气流强度变化的曲线。如果气体的温度与液桥的支撑杆的温度相同，则与热毛细管应力相反的气流会严重破坏基本流量的稳定性。在顺流配置中，基本状态是稳定的。对于液桥的两个纵横比，讨论了中性雷诺数随环形气流强度变化的曲线。