Estimates on the velocity of a rigid body moving in a fluid
We obtain estimates of all components of the velocity of a 3D rigid body moving in a viscous incompressible fluid without any symmetry restriction on the shape of the rigid body or the container. The estimates are in terms of suitable norms of the velocity field in a small domain of the fluid only, provided the distance $h$ between the rigid body and the container is small. As a consequence we obtain suitable differential inequalities that control the distance $h$. The results are obtained using the fact that the vector field under investigation belongs to suitable function spaces, without any use of hydrodynamic equations.
math.AP↗