This talk is motivated by piezoelectric energy harvesting, where cantilevered beams undergo large deflections and interact with a surrounding flow. We begin with the nonlinear beam equation, which provides the analytic foundation for the coupled model. The first part focuses on the linearized flow–beam dynamics under the Kutta–Joukowski coupling and mixed boundary conditions. Within the semigroup framework, we establish well-posedness for this linear system, capturing the effects of the flow coupling on the beam dynamics. The nonlinear problem, studied through a structurally damped version of the beam, is solved via a fixed-point argument, and solutions to the original system are recovered as damping vanishes. The analysis unites nonlinear beam theory with quasilinear PDE methods and offers a pathway toward more realistic models of cantilever-based fluid–structure interactions relevant to piezoelectric energy harvesting.