【摘要】 对于低温液空、液化天然气储罐的需求随着近年来储能技术的发展日益增长。研究人员大多通过数值方法探究低温混合物间双扩散对流引起的翻滚现象。但由于缺乏实验数据支撑，数值仿真模型在实际应用中的可信度仍有待提高。本文创新性地将纹影法应用于多组分混合物分层界面的双扩散对流研究中，设计并搭建了常温混合物双扩散分层可视化实验系统。通过调整盐水溶液浓度差、外热流强度及加热位置和PIVlab后处理图像，获得了密度分层界面处翻滚时间、速度、涡量等参数与加热功率、界面两侧浓度差和加热位置的关系，并提出了加热功率、Ra数与混合物翻滚出现时间的拟合关系式，可为预防低温混合物翻提供有效参考。更多还原

【Abstract】 With the development of energy storage technology in recent years, the demand for cryogenic liquid air and liquefied natural gas tanks has been increasing. Researchers mainly explore the rollover phenomenon induced by double-diffusive convection in cryogenic mixtures through numerical methods. However, due to the lack of experimental data, the credibility of numerical simulation models in practical applications still needs to be improved. This paper innovatively applies the Schlieren method to study double-diffusive convection at the stratified interface of multi-component mixtures. A visualization experimental system for double-diffusive stratification of mixtures at room temperature was designed and constructed. By adjusting the concentration difference of the saltwater solution, the intensity of external heat flux, and the heating position, along with PIVlab postprocessing images, parameters such as rolling time, velocity, and vorticity at the density-stratified interface were obtained. The relationships between these parameters and heating power, concentration difference across the interface, and heating position were analyzed. A fitting relationship between heating power, Rayleigh number and the occurrence time of mixture rolling was proposed,providing an effective reference for preventing rolling in cryogenic mixtures.更多还原