||A boundary control problem for the steady self-propelled motion of a rigid body in a Navier–Stokes fluid
Hishida, Toshiaki ,
Silvestre, Ana LeonorTakahashi, Takeo
Annales de l'Institut Henri Poincaré C, Analyse non linéaire
1541 , 2017-12 , Elsevier
Consider a rigid body S⊂R^3 immersed in an infinitely extended Navier–Stokes fluid. We are interested in self-propelled motions of S in the steady state regime of the system rigid body-fluid, assuming that the mechanism used by the body to reach such a motion is modeled through a distribution of velocities v□ on ∂S. If the velocity V of S is given, can we find v□ that generates V? We show that this can be solved as a control problem in which v□ is a six-dimensional control such that either Suppv□⊂Γ, an arbitrary nonempty open subset of ∂Ω, or v□⋅n|∂Ω=0. We also show that one of the self-propelled conditions implies a better summability of the fluid velocity.