Lp-strong solution to fluid-rigid body interaction system with Navier slip boundary condition

We study a fluid-structure interaction problem describing movement of a rigid body inside a bounded domain filled by a viscous fluid. The fluid is modelled by the generalized incompressible Naiver-Stokes equations which include cases of Newtonian and non-Newtonian fluids. The fluid and the rigid body are coupled via the Navier slip boundary conditions and balance of forces at the fluid-rigid body interface. Our analysis also includes the case of the nonlinear slip condition. The main results assert the existence of strong solutions, in an L-p- L-q setting, globally in time, for small data in the Newtonian case, while existence of strong solutions in L-p-spaces, locally in time, is obtained for non-Newtonian case. The proof for the Newtonian fluid essentially uses the maximal regularity property of the associated linear system which is obtained by proving the R-sectoriality of the corresponding operator. The existence and regularity result for the general non-Newtonian fluid-solid system then relies upon the previous case. Moreover, we also prove the exponential stability of the system in the Newtonian case.

Automated summary

The study investigates fluid-structure interaction problem of a rigid body moving inside a viscous fluid, considering both Newtonian and non-Newtonian fluids. It establishes the existence and regularity of solutions, globally for small data in the Newtonian case and locally for non-Newtonian case, with proofs based on linear system properties and sectoriality of corresponding operator. The study also discusses the exponential stability of the system in the Newtonian case.