Acoustic characteristics of phase-synchronized adjacent propellers

Turhan, Burak; Jawahar, Hasan Kamliya; Gautam, Abhishek; Syed, Shahjahan; Vakil, Gaurang; Rezgui, Djamel; Azarpeyvand, Mahdi

Abstract

This experimental study investigates the effect of blade phase angle on noise attenuation in two adjacent, electronically synchronized propellers. Acoustic measurements were performed in an aeroacoustic wind tunnel with a distributed electric propulsion system that involved the adjustment of relative phase angles of 2-bladed propellers between Δψ = 0° and 90°. Ranges of advance ratios (J = 0–0.73) were investigated at a fixed propeller rotation speed of 5000 rpm. The investigation explored the impact on noise directivity and frequency characteristics. The findings reveal significant reductions in noise directivity and tonal noise at the blade pass frequency (BPF). A relative phase angle of Δψ = 90° demonstrated the maximum noise reduction, with an 8 dB decrease at the first BPF and a 2 dB reduction in overall sound pressure level at J = 0. For in-flow conditions (J > 0), a relative phase angle of Δψ = 90° resulted in significant noise reductions of about 24 dB in the first BPF and 6 dB in overall sound pressure level, compared to Δψ = 0°. These observations offer critical insights into the use of the propeller's relative phase angle as an effective noise control method in the distributed electric propulsion system.

Citation

Turhan, B., Jawahar, H. K., Gautam, A., Syed, S., Vakil, G., Rezgui, D., & Azarpeyvand, M. (2024). Acoustic characteristics of phase-synchronized adjacent propellers. Journal of the Acoustical Society of America, 155(5), 3242-3253. https://doi.org/10.1121/10.0025990

• Journal Article Type: Article
• Acceptance Date: Apr 23, 2024
• Online Publication Date: May 14, 2024
• Publication Date: May 14, 2024
• Deposit Date: Sep 16, 2024
• Publicly Available Date: Sep 20, 2024
• Journal: The Journal of the Acoustical Society of America
• Print ISSN: 0001-4966
• Electronic ISSN: 1520-8524
• Publisher: Acoustical Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 155
• Issue: 5
• Pages: 3242-3253
• DOI: https://doi.org/10.1121/10.0025990
• Public URL: https://nottingham-repository.worktribe.com/output/34874864
• Publisher URL: https://pubs.aip.org/asa/jasa/article/155/5/3242/3293199/Acoustic-characteristics-of-phase-synchronized