We study an unsteady nonlinear fluid-structure interaction problem where a
two-dimensional viscous incompressible Newtonian fluid and a one-dimensional
elastic structure, located on one part of the fluid domain boundary, interact. The
fluid motion is modeled by the two-dimensional incompressible Navier–Stokes
equations set in an unknown domain which depends on the structure’s displacement.
We consider longitudinal as well as transversal structure displacement. We assume
that the longitudinal displacement of the structure satisfies a wave equation whereas
the transversal displacement follows a beam equation with inertia of rotation. The
fluid and structure systems are coupled through a kinematic condition which
corresponds to a no-slip condition at the fluid-structure interface and the
fluid exerts a force on the elastic structure. We prove the existence and
uniqueness of strong solution to the considered problem with no gap between the
initial conditions regularity and the ones obtained in positive time. To our
knowledge, this is the first result regarding existence and uniqueness of strong
solutions for fluid-beam interaction problem in the unsteady case taking into
account both the transversal displacement and the longitudinal structure
displacement.