Permeable Structures for Leading Edge Noise Reduction

Ocker C, Czwielong F, Geyer T, Paruchuri C, Merkel M, Becker S (2021)

Publication Type: Conference contribution, Conference Contribution

Publication year: 2021

Original Authors: Christof Ocker, Felix Czwielong, Thomas F. Geyer, Paruchuri Chaitanya, Markus Merkel, Stefan Becker

ISBN: 9781624106101

DOI: 10.2514/6.2021-2192


An experimental investigation on the acoustic and aerodynamic effect of permeable structures at airfoils and fan blades under distorted inflow conditions was performed. The study focuses on the position and the extent of the porous structure with respect to the leading edge. In a first step, aerodynamic and aeroacoustic measurements are carried out in an aeroacoustic wind tunnel on a large number of airfoils for various wind speeds and angles of attack. The airfoils were made of an aluminum alloy using a powder bed fusion based additive manufacturing process. The permeable structure is located either directly at the leading edge or at a short distance downstream of the leading edge with an extent of 5~\%, 10~\%, and 15~\% of the total chord length. Based on the results from the wind tunnel measurements, unskewed fan blades with four different permeable leading edge designs were constructed in a second step. The axial fan measurements were examined with regard to their aerodynamic and acoustic properties under grid-generated turbulent inflow conditions. First, the axial fan performances are compared at the same rotational speed and then at varying rotational speeds to obtain the same total-to-static pressure rise. It was observed for both, airfoil and fan blades, that a permeable structure downstream from the leading edge improves the aerodynamics and the noise reduction in comparison to a permeable structure directly at the leading edge.

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Ocker, C., Czwielong, F., Geyer, T., Paruchuri, C., Merkel, M., & Becker, S. (2021). Permeable Structures for Leading Edge Noise Reduction. In Proceedings of the AIAA AVIATION 2021 FORUM.


Ocker, Christof, et al. "Permeable Structures for Leading Edge Noise Reduction." Proceedings of the AIAA AVIATION 2021 FORUM 2021.

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