The fluid-structure interaction of an airfoil under two-dimensional inviscid blade-vortex interaction (BVI) was numerically studied using an unstructured mesh flow solver. The flow solver was based on a vertex-centered finite-volume method and an implicit point Gauss-Seidel relaxation scheme. The accuracy of solution is enhanced by adopting a multi-level solution-adaptive dynamic-mesh technique. The aeroelastic behavior of the airfoil is predicted by coupling the flow solver with an idealized two degree-of-freedom spring system. The effect of BVI on the aeroelastic displacement of a stationary airfoil and an airfoil oscillating at a neutral flutter velocity is investigated. Interaction of travelling vortex with an airfoil under forced harmonic oscillation is also studied. The results are compared with those of an airfoil without BVI and without motion.