短时微重力环境下的浮力-热毛细对流

在NMLC落塔中,以大Pr数硅油作为实验介质,对短时微重力环境下矩形液池中的液面变形和浮力热毛细对流进行了初步的实验研究。观测了气液自由界面的变形过程,确定了重定位时间,并验证了毛细爬升的两个特征时间;通过实验发现楔形结构和挡板对于液面控制有一定的作用,但是要想获得更好的控制效果,还需要采取其它措施使内角处不满足Concus-Finn条件;运用PIV方法得到了液体内部对流速度场,观察到了在重力水平突变和液面大变形的条件下浮力热毛细对流的转变过程。

Buoyant-thermocapillary convection under short period of microgravity

In the Drop Tower of National Microgravity Laboratary of China,preliminary experimental study was carried out on free surface deformation and Buoyant-Thermocapillary convection during a short-period of microgravity for silicone oil with a high Prantdl number.The deformation process of the free surface was observed,and the reorientation time was detected which was coincident with precious studies on capillary rise.Various structures on sidewalls were used to avoid the free surface deformation and some effects were achieved,but the essential control of free surface required more operations for dissatisfying the Concus-Finn Condition in the interior corner. And for the first time,the thermocapillary flow was observed during the free fall with the great changes in gravity level and shape of the flow field by PIV method.