航天器贮箱内液体晃动阻尼研究(一):理论分析

在理想流假设及线性化的自由表面边界条件的基础上,对刚性容器中液体小幅晃动进行了流体相似律的研究。得到了晃动的固有频率及各部分阻尼随特征长度、特征运动粘性系数以及特征重力加速的变化关系。此外还分析了壁面阻尼,受污染的自由液面阻尼以及液体的内部阻尼这几部分晃动阻尼的相对关系,以及它们随各个特征参量的变化情况。分析发现各部分的晃动阻尼比取决于一个无量纲参数,内部阻尼所占的比例随着运动粘性系数的增大、特征尺寸的减小、特征重力加速度的减少而增大,因此在某些情况下内部阻尼不可忽略。

Study on Sloshing Damping in a Container of Spacecraft (Part Ⅰ): Theory

Based on irrotational flow hypothesis and linearized free surface boundary condition,the similarity law of liquid sloshing with small amplitude is studied in this paper.The relationship between sloshing frequencies,damping of different parts and characteristic length,characteristic kinematic viscosity,characteristic acceleration of gravity is obtained.Additionally,damping at wall,damping at contaminated free surface and inner damping are compared,and how they change with characteristic parameter is studied.It is found that the damping ratio of different parts is determined by a dimensionless number,and the percent of inner damping gets larger with the increasing of kinematic viscosity,the decreasing of characteristic length and characteristic acceleration of gravity.So in some cases the inner damping can't be neglected.