A Low-Cost Anechoic Chamber for Rotor Aeroacoustics Research: Design and Validation

A new anechoic chamber was built at the Łukasiewicz Research Network – Institute of Aviation in Warsaw, Poland, for the purpose of research on aeroacoustics of rotor systems. In order to minimize costs and construction time, a drywall-based design was employed, consisting of a steel frame placed on vibration isolators, mineral wool insulation, and plasterboard cladding. The interior of the chamber was lined with acoustic foam wedges to ensure the anechoic condition. The average background noise level in the chamber was measured at 18.1 dB(A), and the anechoic condition was confirmed down to 315 Hz, and under certain conditions down to 125 Hz, in accordance with the ISO 3745 standard. The acoustic performance of the chamber was further validated through aeroacoustic tests of a benchmark rotor. The results showed very good agreement of the rotor’s acoustic characteristics with the reference data, including precise replication of key harmonics, confirming the chamber’s suitability for aeroacoustic testing.