Determination of fluid force resisting to rigid body motion

Motion of a rigid body in a viscous fluid

We introduce a concept of weak solution for a boundary value problem modelling the motion of a rigid body immersed in a viscous fluid. The time variation of the fluid’s domain (due to the motion of the rigid body) is not known a priori, so we deal with a free boundary value problem. Our main theorem asserts the existence of at least one weak solution for this problem. The result is global in ti...

RNG Rigid Body Motion

This note outlines how the coupling between the motion of rigid bodies immersed in a fluid and the motion of this fluid is handled in XNS. For a rigid body one has a group of nodes which define the surface of the rigid body called “reference node group” (RNG). For each RNG we save the properties of motion in arrays which in the following we will call “RNG arrays”. They contain the bottom and to...

Non-Rigid Body Motion

During the last few years motion analysis has developed into a major field of interest in image analysis and understanding . Considerable progress has been made as evidenced by the number of publications . However , most of these have been confined to the study of rigid body mot ion . Very few have addressed the issue of non-rigid body motion which poses many interesting and difficult problems ...

The Lagrange rigid body motion

Stabilization of a fluid-rigid body system

We consider the mathematical model of a rigid ball moving in a viscous incompressible fluid occupying a bounded domain Ω, with an external force acting on the ball. We investigate in particular the case when the external force is what would be produced by a spring and a damper connecting the center of the ball h to a fixed point h1 ∈ Ω. If the initial fluid velocity is sufficiently small, and t...