Studies by visualisation of flows emerging downstream of a grid

An experimental study has been carried out on airflows crossing grids made of perforated fabrics. These textile grids are often utilised in solar protection due to their perforations which produce a ventilation of the protection. This ventilation depends on parameters like the air injection velocity or the perforations ratio. Nonintrusive visualisation techniques such as the laser tomography or the particle image velocimetry were used in order to obtain qualitative and quantitative results, respectively, for this flow type. Two configurations were studied: the first one concerns the airflow downstream of a grid developing in a half-enclosed space. The second one concerns the same flow, but in addition disturbed by a cross flow. Characteristic structures and velocities of these flows were analysed.