%0 Journal Article
%T THE OSCILLATORY THERMOCAPILLARY CONVECTION IN A FLOATING ZONE<br>半浮区液桥热毛细振荡流
%A Tang Zemei
%A Ar Yan
%A Hu Wenrui
%A <br>唐泽眉
%A 阿燕
%A 胡文瑞
%J 力学学报
%D 1999
%I 
%X The convection driven by buoyancy is weaken in microgravity environment. It is possible to obtain a high-quality and large-scale crystal by using floating zone method without pollution and shear from wall of the container in space. The convection driven by surface-tension gradient at the free surface, called as thermocapillary convection, will be dominant in microgravity environment. The half floating zone has been used as one of the models to study thermocapillary convection since the end of 1970s. The experiments discovered that the steady and axisymmetric thermocapillary convection becomes unsteady and asymmetric oscillatory convection if the applied temperature difference is over the critical value. The thermocapillary oscillatory convection will affect the quality of the crystal. The oscillatory mechanism of thermocapillary convection is an open and interesting problem.The transient process from steady convection to oscillatory convection in a liquid bridge of floating half zone with large Prandtl number fluid is studied by using the numerical method of unsteady and three-dimensional calculation in the present paper. The onset process of oscillation and oscillatory features are discussed in detail, and the flow fields and temperature distributions in the cross-section of liquid bridge are obtained. The calculated results for the case of one-g condition on the ground are compared with the experimental one for the same condition. Both results conclude that, the patterns of flow field and temperature field in a horizontal cross-section of liquid bridge rotate at a certain rotating velocity, however, the azimuthal velocity at a fixed point changes alternately between positive and negative values.
%K thermocapillary convection
%K three-dimensional numerical simulation
%K microgravity fluid mechanics<br>热毛细对流
%K 三维数值模拟
%K 微重力流体力学
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=5D344E2AD54D14F8&jid=4100DA4A1A3BA1B0CE5AD99AE1DFB420&aid=40FE1B66BF8D8C3E&yid=B914830F5B1D1078&vid=4AD960B5AD2D111A&iid=E158A972A605785F&sid=BFB86B6ED3A99B9D&eid=B941678158018439&journal_id=0459-1879&journal_name=力学学报&referenced_num=1&reference_num=15