圆柱类转子构件在流体中的振动阻力研究

依据流体力学的粘性阻力理论,以运动的转子构件--圆柱体为主体,利用矢量分析方法,导出了圆柱体在流体中横向振动时受到的流体阻力解析表达式.分析结果表明圆柱体在流体中横向振动时受到的阻力包括惯性项和阻尼项两部分,其动特性系数不仅与流体性质及圆柱体的结构尺寸有关,而且还与圆柱体的振动角速度有关.同时发现,惯性项中除了包括圆柱体在理想流体中横向振动时受到的惯性阻力外还增加了与粘性有关的部分;而阻尼项则由与粘性有关的两部分组成,其中一部分与流体密度有关,而另一部分与流体密度无关.导出的公式可用于转子系统的流固耦合动力学有限元建模,同时对流体机械及潜液机械构件的动力学设计具有一定指导意义.

Study of Moving Resistance of Vibrating Cylinder Immersed in Unbounded Fluid

In this paper, several analytical expressions for the resistance of a vibrating cylinder immersed in unbounded fluid are obtained through theoretical extrapolations with vector analysis method, which is characterized by choosing the vibrating body as subject, on the basis of viscous fluid mechanics.It concludes that the dynamical coefficients of both the inertial and the damping are not only related to the properties of the fluid and the sizes of the cylinder, but also to the angular velocity of the vibrating body. Meanwhile, two important points are revealed. First, the inertial resistance involves not only the corresponding term in the inviscid fluids which is not related to fluid viscosity, but also the term related to fluid viscosity. Second, the damping resistance also includes two parts , both related to fluid viscosity. But one part is related to fluid density, whereas another part is not. Those deduced formulas will have practical value for finite element modeling of rotor systems with fluid-structure coupling problems.