The flow fields around NACA0012, NACA23012 and OA207 airfoils can be calculated by solving the Euler Navier Stokes equations. The far-field noise generated by NACA0012 airfoilvortex interaction is predicted using the combined Euler-Kirchhoff method. The Kirchhoff surfice is selected as one of the grid surfaces. Firstly, the result of flow field under airfoil-vortex interaction can be obtained by solving the Euler equations. Then the result of far-field noise can be obtained by the Kirchhoff method. Finally, the combined Euler-Kirchhoff method developed here is proved to be good for studying blade-vortex interaction noise through sample calculations.