992 resultados para Reynolds, Irving
Resumo:
The experimental investigation of the thermocapillary drop migration in a vertical temperature gradient uns performed on ground. Silicon oil and pure soybean oil were used as experimental medium in drops and as continuous phases, respectively, in the present experiment. The drop migration, under the combined effects of buoyancy: and thermocapillarity, was studied for middle Reynolds numbers in order of magnitude O(10(1)). The drop migration velocities depending on drop diameters were obtained. The present experimental results show relatively small migration velocity in comparison with the one suggested by Young et nl. for linear theory of small Reynolds number. An example of flow patterns inside the drop was observed by PIV method.
Resumo:
讨论了液滴热毛细迁移的空间实验装置，该实验是中国神舟号飞船中的一个项目。与国际上同类装置比较，它具有不需要宇航员直接操作，领先程序自动控制及遥科学手段完成全部科学实验的能力。它不仅能完成大Reynolds数的液滴迁移实验，而且在这类空间装置上使用了等厚型光学干涉系统。
Resumo:
近年来,Rubinstein和Barton利用Yakhot和Orszag湍流重正化群方法推导非线性Reynolds应力模型,但是他们分析计算过程中存在着一些不自洽的地方.文中利用重正化群方法,对Reynolds应力的数学表达式作二阶微扰展开,从理论上推导得到非线性Reynolds应力模型,其数学形式与从量纲分析和数学物理性质的合理性讨论得到的通用模型形式完全相同,另外从理论上计算了各待定湍流常数.
Resumo:
The high Reynolds number flow contains a wide range of length and time scales, and the flow
domain can be divided into several sub-domains with different characteristic scales. In some
sub-domains, the viscosity dissipation scale can only be considered in a certain direction; in some
sub-domains, the viscosity dissipation scales need to be considered in all directions; in some
sub-domains, the viscosity dissipation scales are unnecessary to be considered at all.
For laminar boundary layer region, the characteristic length scales in the streamwise and normal
directions are L and L Re-1/ 2 , respectively. The characteristic length scale and the velocity scale in
the outer region of the boundary layer are L and U, respectively. In the neighborhood region of
the separated point, the length scale l<
