Antontsev, S. N.de Oliveira, H. B.Khompysh, Kh.2022-07-252022-07-252022http://hdl.handle.net/10400.1/18088In this work, we consider the nonlinear initial-boundary value problem posed by the Kelvin-Voigt equations for non-homogeneous and incompressible fluid flows with fully anisotropic diffusion, relaxation and damping. Moreover, we assume that the momentum equation is perturbed by a damping term which, depending on whether its signal is positive or negative, may account for the presence of a source or a sink within the system. In the particular case of considering this problem with a linear and isotropic relaxation term, we prove the existence of global and local weak solutions for the associated initial-boundary value problem supplemented with no-slip boundary conditions. When the damping term describes a sink, we establish the conditions for the polynomial time decay or for the exponential time decay of these solutions.porKelvin-Voigt equationsNonhomogeneous and incompressible fluidsAnisotropic PDEsPower-lawsExistenceLarge time behaviorjournal article10.1007/s00030-022-00794-z1420-9004