Coarse Air Filter

 Mobile phone antennas are very regularly the subject of wind tunnel measurements (1, 2, 3). Outdoors, however, they are often not exposed to such uniform inflow conditions as provided by our tunnel built for aviation applications. Comparisons to facilities with lower flow quality have shown that the turbulence in the inflow does indeed exert a – reducing – influence on the wind loads. In order to quantify this effect precisely, measurements with grids in the nozzle are planned. In a first step, the free stream in the test section was investigated. Initial evaluations show a turbulence level of about 3.2 per cent.