An Engineering Solution for Fan Aeroacoustics Measurements Correction in a Non-Anechoic Testing Environment

- Nowadays, acoustic signatures of daily used applications are to be minimized. The study of noise generated through aerodynamic interaction with moving bodies has passed through different phases since the early 50s, and this leads to the evolvement of many analytical, empirical and computational techniques in order to be able to estimate the emitted noise. Concerning fan blades, until now the researches are still going for a reliable method for noise estimation during the early phases of design which help in the development of blades with a lower aeroacoustic signature, the Brooks, Pope and Marcolini (BPM) model was chosen to be compared with the experimental data after correction to validate the correction methodology in the highly clarified broad band noise of 1/3 octave sound power level (SPL). The mid-band after the tenth harmonic of the blade passing frequency till the maximum high-fidelity frequency of BPM model will be a reference for comparing the corrected measured data to the original and the results of BPM model. The correction technique was originally needed during the case study of a benchmark HVAC fan acoustics measurement in a non-anechoic environment, the fan was of (1.2 m) outer diameter and a hub diameter of (0.6 m) consists of 12 blades each of (30 cm) length and rotating with 1500 RPM. A MATLAB tool was developed for the purpose of correction.