AN ANALYTICAL SOLUTION OF TRANSVERSE VIBRATION OF RECTANGULAR PLATES SIMPLY SUPPORTED AT TWO OPPOSITE EDGES WITH ARBITRARY NUMBER OF ELASTIC LINE SUPPORTS IN ONE WAY

ＡＮＡＮＡＬＹＴＩＣＡＬＳＯＬＵＴＩＯＮＯＦＴＲＡＮＳＶＥＲＳＥＶＩＢＲＡＴＩＯＮＯＦＲＥＣＴＡＮＧＵＬＡＲＰＬＡＴＥＳＳＩＭＰＬＹＳＵＰＰＯＲＴＥＤＡＴＴＷＯＯＰＰＯＳＩＴＥＥＤＧＥＳＷＩＴＨＡＲＢＩＴＲＡＲＹＮＵＭＢＥＲＯＦＥＬＡＳＴＩＣＬＩＮＥ...     

APPROXIMATION THEORY OF THREE DIMENSIONAL ELASTIC PLATES AND ITS BOUNDARY CONDITIONS WITHOUT USING KIRCHHOFF－LOVE ASSUMPTIONS

ＡＰＰＲＯＸＩＭＡＴＩＯＮＴＨＥＯＲＹＯＦＴＨＲＥＥＤＩＭＥＮＳＩＯＮＡＬＥＬＡＳＴＩＣＰＬＡＴＥＳＡＮＤＩＴＳＢＯＵＮＤＡＲＹＣＯＮＤＩＴＩＯＮＳＷＩＴＨＯＵＴＵＳＩＮＧＫＩＲＣＨＨＯＦＦ－ＬＯＶＥＡＳＳＵＭＰＴＩＯＮＳＣｈｉｅｎＷｅｉ－ｚａｎｇ（...     

FINITE ELEMENTAN ALYSIS FOR THE UNSTEADY NEARSHORECIR CULATION DUE TO WAVE－CURRENT INTER－ACTION（I）──NUMERICAL MODEL

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＴＨＥＵＮＳＴＥＡＤＹＮＥＡＲＳＨＯＲＥＣＩＲＣＵＬＡＴＩＯＮＤＵＥＴＯＷＡＶＥ－ＣＵＲＲＥＮＴＩＮＴＥＲ－ＡＣＴＩＯＮ（Ｉ）——ＮＵＭＥＲＩＣＡＬＭＯＤＥＬＷｕＷｅｉ－ｘｉｏｎｇ（吴伟雄）（Ｔｏｎｇｊ...     

A priori estimates to the maximum modulus of generalized solutions of a class of quasilinear elliptic equations with anisotropic growth conditions

ＡＰＲＩＯＲＩＥＳＴＩＭＡＴＥＳＴＯＴＨＥＭＡＸＩＭＵＭＭＯＤＵＬＵＳＯＦＧＥＮＥＲＡＬＩＺＥＤＳＯＬＵＴＩＯＮＳＯＦＡＣＬＡＳＳＯＦＱＵＡＳＩＬＩＮＥＡＲＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳＷＩＴＨＡＮＩＳＯＴＲＯＰＩＣＧＲＯＷＴＨＣＯＮＤＩＴＩＯＮ...     

FINITE ELEMENT ANALYSIS FOR THE UNSTEADY NEARSHORE CIRCULATION DUE TO WAVE－CURRENT INTERACTION（II）──TWO－STEP EXPLICIT FINITE ELEMENT METHOD

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＴＨＥＵＮＳＴＥＡＤＹＮＥＡＲＳＨＯＲＥＣＩＲＣＵＬＡＴＩＯＮＤＵＥＴＯＷＡＶＥ－ＣＵＲＲＥＮＴＩＮＴＥＲＡＣＴＩＯＮ（ＩＩ）──ＴＷＯ－ＳＴＥＰＥＸＰＬＩＣＩＴＦＩＮＩＴＥＥＬＥＭＥＮＴＭＥＴＨＯＤＷ...     

Iterative algorithms for finding approximate solutions of completely generalized strongly nonlinear quasivariational inequalities

ＩＴＥＲＡＴＩＶＥＡＬＧＯＲＩＴＨＭＳＦＯＲＦＩＮＤＩＮＧＡＰＰＲＯＸＩＭＡＴＥＳＯＬＵＴＩＯＮＳＯＦＣＯＭＰＬＥＴＥＬＹＧＥＮＥＲＡＬＩＺＥＤＳＴＲＯＮＧＬＹＮＯＮＬＩＮＥＡＲＱＵＡＳＩＶＡＲＩＡＴＩＯＮＡＬＩＮＥＱＵＡＬＩＴＩＥＳＺｅｎｇＬｕ－ｃ...     

AN APPROXIMATE SOLUTION OF EIGEN－FREQUENCIES OF TRANSVERSE VIBRATION OF RECTANGULAR PLATES WITH ELASTICAL RESTRAINTS

ＡＮＡＰＰＲＯＸＩＭＡＴＥＳＯＬＵＴＩＯＮＯＦＥＩＧＥＮ－ＦＲＥＱＵＥＮＣＩＥＳＯＦＴＲＡＮＳＶＥＲＳＥＶＩＢＲＡＴＩＯＮＯＦＲＥＣＴＡＮＧＵＬＡＲＰＬＡＴＥＳＷＩＴＨＥＬＡＳＴＩＣＡＬＲＥＳＴＲＡＩＮＴＳ（周叮）ＡＮＡＰＰＲＯＸＩＭＡＴＥＳＯＬＵＴ...     

A UNIFORMLY DIFFERENCE SCHEME OF SINGULAR PERTURBATION PROBLEM FOR A SEMILINEAR ORDINARY DIFFERENTIAL EQUATION WITH MIXED BOUNDARY VALUE CONDITION

ＡＵＮＩＦＯＲＭＬＹＤＩＦＦＥＲＥＮＣＥＳＣＨＥＭＥＯＦＳＩＮＧＵＬＡＲＰＥＲＴＵＲＢＡＴＩＯＮＰＲＯＢＬＥＭＦＯＲＡＳＥＭＩＬＩＮＥＡＲＯＲＤＩＮＡＲＹＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＷＩＴＨＭＩＸＥＤＢＯＵＮＤＡＲＹＶＡＬＵＥＣＯＮＤＩＴ...     

AN ANALYTICAL SOLUTION OF HEAT CONDUCTION ON A LOCALLY NONUNIFORMLY HEATED SURFACE OF A PLATE WITH FINITE THICKNESS

ＡＮＡＮＡＬＹＴＩＣＡＬＳＯＬＵＴＩＯＮＯＦＨＥＡＴＣＯＮＤＵＣＴＩＯＮＯＮＡＬＯＣＡＬＬＹＮＯＮＵＮＩＦＯＲＭＬＹＨＥＡＴＥＤＳＵＲＦＡＣＥＯＦＡＰＬＡＴＥＷＩＴＨＦＩＮＩＴＥＴＨＩＣＫＮＥＳＳ（王明锐）（靳辉）ＡＮＡＮＡＬＹＴＩＣＡＬＳＯＬＵＴＩ...     

Iterative construction of fixed points for multivalued operators of the monotone type in uniformly smooth Banach spaces

ＩＴＥＲＡＴＩＶＥＣＯＮＳＴＲＵＣＴＩＯＮＯＦＦＩＸＥＤＰＯＩＮＴＳＦＯＲＭＵＬＴＩＶＡＬＵＥＤＯＰＥＲＡＴＯＲＳＯＦＴＨＥＭＯＮＯＴＯＮＥＴＹＰＥＩＮＵＮＩＦＯＲＭＬＹＳＭＯＯＴＨＢＡＮＡＣＨＳＰＡＣＥＳＤｅｎｇＬｅｉ（邓磊）（ＣｈｏｎｇｑｉｎｇＴ...     

Sloshing dynamics modulated cryogenic helium fluids driven by gravity gradient or jitter accelerations associated with slew motion in microgravity

The mathematical formulation of the Dewar container sloshing dynamics for a partially filled liquid of cryogenic superfluid helium II driven by the gravity gradient or jitter accelerations associated with slew motion in a microgravity environment are studied. The numerical computation of sloshing dynamics is based on the non-inertia container bounded frame and the solution of time-dependent, three-dimensional partial differential equations subjected to the initial and boundary conditions. This study discloses that the capillary effect of sloshing dynamics governs the liquid-vapor interface fluctuations driven by the gravity gradient or jitter accelerations associated with slew motion in a microgravity environment. The peculiar behavior of superfluid helium in response to sloshing dynamics is also investigated.     

微重力场中液体在带隔板球腔内的晃动

本文讨论微重力场中带球面隔板的球腔内液体晃动问题。选择Legendre函数作为Ritz方法的基函数,计算液体的自由晃动及腔体横向振动激励的受迫振动。计算结果表明,自由晃动频率随隔板位置的下降而趋于升高。液体晃动的动力学效应可用等效的质量—弹簧系统模拟。     

Coupled vibrations of a partially fluid-filled cylindrical container with an internal body including the effect of free surface waves

Internal bodies (baffles) are used as damping devices to suppress the fluid sloshing motion in fluid-structure interaction systems. An analytical method is developed in the present article to investigate the effects of a rigid internal body on bulging and sloshing frequencies and modes of a cylindrical container partially filled with a fluid. The internal body is a thin-walled and open-ended cylindrical shell that is coaxially and partially submerged inside the container. The interaction between the fluid and the structure is taken into account to calculate the sloshing and bulging frequencies and modes of the coupled system using the Rayleigh quotient, Ritz expansion and Galerkin method. It is shown that the present formulation is an appropriate and new approach to tackle the problem with good accuracy. The effects of fluid level, number of nodal diameters, internal body radius and submergence ratio on the dynamic characteristics of the coupled system are also investigated.     

Motion analysis of a spinning satellite system with off-centre tanks partially filled with liquid

The sloshing problem for, a spherical tank partially filled with liquid is analysed in this paper. The study is based on the goveming, equations of fluid dynamics and the Euler's equations of systems with the influences of tank off-centering, fluid vortices and the Coriolis' acceleration on the motion states of the systems taken into consideration. In the study, we adopt the concept of uniform vortex motion of fluid generalized by Pfeiffer and apply the boundary element method (BEM) to the calculation of the natural frequence and the velocity field of the liquid sloshing. The motion characteristics of the flow-solid spinning system is then analysed. The project is supported by the National Natural Science Foundation of China and Ministry of Astronautics.     

Damping computation of liquid sloshing in containers aboard spacecraft

Under the non-rotating assumption, a method for the calculation of damping of fuel sloshing with small amplitude in containers aboard spacecraft is proposed in the present paper. And we have presented an eigen-value equation for sloshing damping and frequency computation. This equation may be solved by Ritz or Galerkin methods for a container of simple geometry or by finite element method for a container of arbitrary geometric shape even with rigid baffles. The simulated results show that the equivalent damping coefficients is directly proportional to fuel‘s viscosity, whereas it almost exhibits no influence on sloshing frequencies. The drawback of the proposed method lies in expensive computation cost. Thus far, it hasn‘t yet be applied to a container with elastic baffles.     

Motion stability dynamics for spacecraft coupled with partially filled liquid container

This paper presents a canonical Hamiltonian model of liquid sloshing for the container coupled with spacecraft. Elliptical shape of rigid body is considered as spacecraft structure. Hamiltonian system is an important form of mechanical system. It mostly used to stabilize the potential shaping of dynamical system. Free surface movement of liquid inside the container is called sloshing. If there is uncontrolled resonance between the motion of tank and liquid-frequency inside the tank then such sloshing can be a reason of attitude disturbance or structural damage of spacecraft. Equivalent mechanical model of simple pendulum or mass attached with spring for sloshing is used by many researchers. Mass attached with spring is used as an equivalent model of sloshing to derive the mathematical equations in terms of Hamiltonian model. Analytical method of Lyapunov function with Casimir energy function is used to find the stability for spacecraft dynamics. Vertical axial rotation is taken as the major axial steady rotation for the moving rigid body.     

A boundary element method for small-amplitude viscous fluid sloshing in couple with structural vibration

A boundary element method is presented for the coupled motion analysis of structural vibration with small-amplitude fluid sloshing in two-dimensional space. The linearized Navier-Stokes equations are considered in frequency domain and transformed into boundary integral equations. An appropriate fundamental solution for the Helmholtz equation with pure imaginary constant is found. The condition of zero-stress is imposed on the free surface, and non-slip condition of fluid particles is imposed on the walls of the container. For rigid motion models, the expressions for added mass and added damping to the structural motion equations are obtained. Some typical numerical examples are presented.     

边界元法分析粘性液体小幅晃动

本文采用了边界元法对容器中粘性、不可压缩液体小幅晃动进行数值分析。在频域内考虑二维线性化Navier-Stokes方程,以问题的物理变量作为数值分析的未知函数,并推导了该问题分析的边界积分方程。自由面上的动力学条件为法向正应力和切向剪应力为零,这两个条件本身是线性的,避免了采用无粘势理论边界条件的非线性,固壁面上采用流体质点与固壁质点速度相等的条件,在数值计算过程中,结合有限差分法对边界条件进行了处理,由此建立了问题的一个边界元数值求解过程。     

Nonlinear modeling of tuned liquid dampers (TLDs) in rotating wind turbine blades for damping edgewise vibrations

Tuned liquid dampers (TLDs) utilize the sloshing motion of the fluid to suppress structural vibrations and become a natural candidate for damping vibrations in rotating wind turbine blades. The centrifugal acceleration at the tip of a wind turbine blade can reach a magnitude of 7–8g. This facilitates the use of a TLD with a relatively small fluid mass and with feasible geometric dimensions to mitigate the lightly-damped edgewise vibrations effectively. In the present paper, modal expansions are carried out directly on the velocity field and the free surface of the sloshing liquid in the rotating coordinate system. A formulation has been proposed leading to coupled nonlinear ordinary differential equations, which have been obtained through the Galerkin variational approach together with the modal expansion technique. Two models, with one sloshing mode and three sloshing modes, have been studied in the numerical simulation. It is shown that the one-mode model is able to predict the sloshing force and the damped structural response accurately, since the primary damping effect on the structure is achieved by the first sloshing mode of the fluid. Although it is unable to predict the fluid free-surface elevation equally well, the one-mode model can still be utilized for the design of TLD. Parametric optimization of the TLD is carried out based on the one-mode model, and the optimized damper effectively improves the dynamic response of wind turbine blades.     

A study of sloshing absorber geometry for structural control with SPH

A liquid sloshing absorber consists of a container, partially filled with liquid. The absorber is attached to the structure to be controlled, and relies on the structure's motion to excite the liquid. Consequently, a sloshing wave is produced at the liquid free-surface within the absorber, possessing energy dissipative qualities. The primary objective of this work is to numerically demonstrate the effect of a sloshing absorber's shape on its control performance. Smoothed Particle Hydrodynamics (SPH) is used to model fluid–structure interaction of the structure/sloshing absorber system in two dimensions. The structure to be controlled is a lightly damped single degree-of-freedom structure. The structure is subjected to a transient excitation and then allowed to respond dynamically, coming to rest either due to its own damping alone or with the added control of the sloshing absorber. It is identified that the control performance of the conventionally used rectangular container geometry can be improved by having inward-angled walls. This new arrangement is robust, and of significant advantage in situations when the external disturbance is of uncertain magnitude.