This paper shows the airflow over two successive, single span tunnel greenhouses into a wind tunnel. The governing Navier-Stokes and continuity equations are solved numerically, using the Galerkin finite element method. The Reynolds number is calculated according to the height of the structures and the inlet free stream velocity and its values are varied from 0.02 to 1 200. The airflow is viscous, incompressible, steady and nominated to be two-dimensional, while the greenhouses are extended to the whole width of the tunnel. Computed values, for the streamwise and cross-wise velocity and pressure, are derived by the solution of the mathematical model, at all points of the computational flow field. The analysis of the results provided numerical predictions, such as streamlines in the flow field, vortices around the structures, distributions of stream-wise velocity and separation- reattachment lengths of the boundary layer. The numerical procedure is validated by the results of other researchers.