Experimental assessment on the performance of hot wire anemometry in and around a permeable medium by comparison with Particle Image Velocimetry

The air flow through a test section partially obstructed by permeable array of wires was measured simultaneously Hot Wire Anemometry (HWA) and Particle Image Velocimetry. objective the study assessment suitability HWA for measurement velocities amid adjacent to groups small obstacles. In present case obstacles are set in regular configuring highly structure. probe placed at three characteristic positions: free close wire array, inside medium, interface between structure flow. measurements were performed with hot operating under natural convection mixed heat transfer, different overheat ratios. Natural plumes extending over several volume elements detected when convection, some cases reaching up 60 mm/s downstream from position. For low velocity flows, can be regarded as offset, which becomes negligible local higher than 0.03 m/s. velocities, regime, intrusivity relevant. Furthermore, used presents linear instability that produces fluctuations. Availing ourselves this phenomenon we verified dynamic response lowest where shows periodic fluctuations; mean (0.131 ± 0.012) m/s showed satisfactory 20 Hz.