Proceedings of the 10th Convention of the
European Acoustics Association
Forum Acusticum 2023


Politecnico di Torino
Torino, Italy
September 11 - 15, 2023





Session: A06-04: Metamaterials for passive control in aeroacoustics - Part II
Date: Friday 15 September 2023
Time: 08:20 - 08:40
Title: Experimental study of surface noise mitigation for propeller in boundary layer ingestion configuration
Author(s): L.A. Castelucci, University of Twente, Drienerlolaan 5, 7522 NB Enschede, Netherlands
C.H. Venner, University of Twente, Drienerlolaan 5, 7522 NB Enschede, Netherlands
Y.H. Wijnant, University of Twente, Drienerlolaan 5, 7522 NB Enschede, Netherlands
Pages: 5779-5786
DOI: https://www.doi.org/10.61782/fa.2023.0814
PDF: https://dael.euracoustics.org/confs/fa2023/data/articles/000814.pdf
Conference proceedings
Abstract

Noise mitigation is critical in the conceptual designs of aircraft. The evolving requirements for noise reduction and the urbanization of aircraft are some reasons why reducing noise is crucial when designing new concepts. Those novel configurations can include complex propulsion-air frame interactions, such as boundary layer ingestion. While research focuses on shrouded solutions, airframe noise mitigation optimization presents a solution for designs that cannot apply shrouding. This paper shows an experimental analysis of surface noise mitigation underneath a propeller under boundary layer ingestion. The propeller is set on the bottom wall of the wind tunnel to generate the boundary layer ingestion. Tripping devices are used to change the boundary layer thicknesses of the flow impinging on the propeller. The noise reduction surfaces are positioned underneath the propeller through a slot on the flat plate. The surface analyzed is a known frequency absorber (quarter-wave resonator) separated from the flow by a Kevlar panel. Two microphone arrays capture the noise coming from the propeller. The results show that the mitigation strategy reduces noise close to the frequencies of interest, but increases the tonal levels of the propeller due to the resonance with the quarter-wave resonators.