Experimental validation of pressure loss in anemometer testing equipment

This work deals with an experimental procedure to validate theoretical equations used for pressure losses inside anemometer testing equipment. This equipment allows for the generation of air flow inside a chamber designed for anemometer calibration testing at different air speeds. To calibrate anemometers to high accuracy, the air flow must have very low turbulence and uniform velocities over the testing chamber cross section. For high performance, the anemometer testing equipment used a closed-circuit wind tunnel design.In designing the anemometer testing equipment, the pressure losses of single components were evaluated as well as overall pressure loss utilizing theoretical equations found in the scientific literature. Once the pressure losses were evaluated, the fan was chosen to ensure volumetric flow, balance pressure losses and above all maximise its performance.With the design completed, the anemometer testing equipment was built, and a campaign of experimental measurements was performed to evaluate the accuracy of the theoretical pressure loss equations. The campaign was performed in two different conditions: closed testing chamber and open testing chamber. The results showed good agreement between the theoretical and experimental pressure losses for the closed testing chamber. Conversely, a discrepancy was revealed for the open condition. The origin of this discrepancy was investigated and a new equation proposed.