Added mass

About: Added mass is a research topic. Over the lifetime, 2849 publications have been published within this topic receiving 47899 citations.

Modelling of radiation damping in fluids by finite elements

Abstract: A very efficient technique is presented to model the effects of radiation damping in the computation of added mass for the dynamic analysis of submerged structures. The structure is assumed to be surrounded by an infinite, incompressible and inviscid fluid field and the effect of the free surface is neglected. The technique is implemented in the finite element analysis of two-dimensional problems, assuming pressure to be the nodal unknown. The implementation procedure is quite simple and the symmetrical and banded form of the matrix of coefficients remains unchanged. With the use of the proposed radiation condition, the fluid field may be truncated at a relatively very short distance from the solid—fluid interface. This results in great computational advantages. Furthermore, a guideline is suggested for the selection of the geometry and the location of the truncation boundary to enhance the computational efficiency. The effectiveness and efficiency of the technique is demonstrated by analysing several cases for different geometries of the solid—fluid interface and the truncation boundary.

Dynamics of mechanical systems with variable mass

Abstract: A rational treatment of the relations of balance for mechanical systems with a time-variable mass and other non-classical supplies. - Systems with mass explicitly dependent on position. - Dynamics of the mass variable body. - Mechanics of multi-component media with exchange of mass and non-classical supplies. - Modeling of fluid-structure interaction: effects of added mass, damping and stiffness. - Dynamics and stability of engineering systems with moving continua.

Finite-Element Solution of Added Mass and Damping of Oscillation Rods in Viscous Fluids

Abstract: This paper presents a finite-element analysis for the cylindrical rods oscillating periodically in an incompressible viscous fluid. A system of discretized equation is obtained from the appropriate Navier-Stokes and continuity equations through Galerkin’s process. The basic unknowns are velocity and pressure. A mixed interpolation method is used. The added mass and viscous damping coefficients which characterize the fluid reaction force due to the rods oscillation can be obtained through a line integration of stress and pressure around the circumference of the rods. For the special case of a cylindrical rod oscillating in a viscous fluid enclosed by a rigid, concentric cylindrical shell, the finite-element solution agrees well with the analytical closed-form solution, which, in turn, has been verified experimentally [1].

Modeling and dynamic behavior of rotating blades carrying a tip mass and incorporating adaptive capabilities

Abstract: The problems of the mathematical modeling and dynamical behavior of rotating blades carrying a tip mass and incorporating adaptive capabilities are considered. The blade is modeled as a thinwalled beam incorporating non-classical features such as anisotropy, transverse shear, secondary warping, and includes the centrifugal and Coriolis force fields. For non-adaptive rotating blades, a thorough validation of the structural model and solution methodology is accomplished. The adaptive capabilities provided by a system of piezoactuators bonded or embedded into the structure are also implemented. Based on the converse piezoelectric effect, the piezoactuators produce a localized strain field in response to an applied voltage, and, as a result, an adaptive change of the dynamic response characteristics is obtained. A combined feedback control law relating the piezoelectrically induced bending moment at the beam tip with the kinematical response quantities appropriately selected is used, and its beneficial effects upon the closed-loop eigenvibration characteristics are highlighted.