Measurement of model propfan noise in high speed wind tunnel

A single-rotation 12-blade propfan whose blades were outfitted with pressure transducers has been tested in a transonic wind tunnel equipped with acoustic probes in order to ascertain both its acoustic and aerodynamic characteristics. The results thus obtained were compared with theoretical predictions for noise radiation. It is found that the nonanechoic environment of the wind tunnel degraded the acoustic results for far-field conditions; nevertheless, measurements in the propfan plane, around which noise radiation was maximum, appear to be valid. Substantial agreement is obtained between experimental results and both near- and far-field acoustic predictions.