Telescope enclosures are used to limit the disturbance caused by the wind on the pointing and tracking performances of telescopes and to preserve primary mirror optical shape. Within the framework of the EC program "ELT Design Study - Contract No. 011863", extended wind tunnel test have been performed to characterize wind turbulent structure inside two different types of enclosures and with different wind screen positions. Also Power Spectral Densities of the turbulent flow have been directly measured. In this paper the results are summarized, together with the limitations associated to the use of scaled models. Mean speed distributions and turbulent energy distributions have been measured. The results are compared with the fields determined with quasisteady approach based on existing turbulence models (namely von Karman). Measurements obtained on the field in the VST enclosure at Paranal are crossed checked with the results obtained in the Boundary Layer wind tunnel.