热毛细对流振荡、转捩及体积效应研究

Thermocapillary flow is one of the most important research topics in microgravity fluid physics. On the recoverable SJ-10 scientific experiment satellite, we have carried out a microgravity experimental study on the thermocapillary convection in an annular pool, which is a typical thermocapillary convection system. Normally, the axisymmetric thermocapillary convection is unstable and will transforms into a three-dimensional flow. However, the bending free surface in microgravity environment has a great influence on thermocapillary convection and its stability. In this project, firstly, the problem such as oscillation characteristics, critical conditions, transition routes and flow pattern transformation will be studied by analyzing the massive results of thermocapillary convective wave experiments in space. In particular, the volume ratio effect will be discussed, thermocapillary instability and its evolution will be analyzed deeply. Secondly, the buoyancy-thermocapillary annular convection model will be established and the corresponding experiments will be carried out on the ground, to obtain the results of buoyancy-thermocapillary convection in the new model system. Thirdly, through three-dimensional direct numerical simulation, the stability of the thermocapillary convection, the three-dimensional flow pattern, the propagation law of the circumferential surface wave and the coupling with the hydrothermal wave will be studied, to reveal the mechanism of thermocapillary convection in annular pool.

热毛细流动问题是微重力流体物理的重要研究内容，作为一种典型的热毛细流动体系，我们在实践十号返回式科学实验卫星上开展了环形液池热毛细对流的空间实验研究。通常情况下，定常轴对称的热毛细对流失稳后转变为三维的流动，空间环境下弯曲的自由面对于热毛细对流及其稳定性又有很大的影响。本项目通过分析热毛细对流表面波空间实验取得的海量实验结果，研究热毛细对流的振荡特征、临界条件、转捩及转捩途径、流动模式转换等，探讨体积效应问题，深入分析热毛细对流的失稳规律及其发展过程；建立流体表面中心加热的柱状浮力-热毛细对流模型，地面开展相应的实验研究，获得新的模型体系的浮力-热毛细对流实验结果；通过三维直接数值模拟，系统研究热毛细对流的流动稳定性、三维流动模式、失稳过程中表面波沿周向的传播规律及与热流体波的耦合作用，研究环形液池热毛细对流的机理。

热毛细流动问题是微重力流体物理的重要研究内容，作为一种典型的热毛细流动体系，我们在实践十号返回式科学实验卫星上开展了环状流的空间实验研究。通常情况下，定常轴对称的热毛细对流失稳后转变为三维流动，空间环境下弯曲的自由面对于热毛细对流及其稳定性又有很大的影响。本项目通过分析热毛细对流表面波空间实验取得的海量实验结果，研究热毛细对流的振荡特征、临界条件、转捩及转捩途径、流动模式转换等，探讨体积效应问题，深入分析热毛细对流的失稳规律及其发展过程；通过三维直接数值模拟，系统研究热毛细对流的流动稳定性、三维流动模式、失稳过程中表面波沿周向的传播规律及与热流体波的耦合作用，研究环状流的机理；配合空间实验开展地面实验研究，并建立了旋转浮力-热毛细对流模型，获得新的模型体系的实验结果。