Predicting noise spectrum of a small drone rotor in a confined environment: a lattice Boltzmann Vles analysis

Predicting noise spectrum of a small drone rotor in a confined environment: a lattice Boltzmann Vles analysis

Riccardo Colombo, Lorenzo Maria Pii, Gianluca Romani, Maurizio Boffadossi

Abstract. The objective of this paper is to study the predictive capabilities of a Very-Large-Eddy-Simulation CFD solver for the simulation of the flow past a small drone propeller blade. The solver is based on a Lattice-Boltzmann Method coupled with an FW-H acoustic analogy to compute the far field noise. The method is able to cope with the anechoic test chamber to predict the complex flow-field and the characteristic boundary layer phenomena (such as laminar separation, transition and reattachment). The acoustic hybrid formulation provides tonal and broadband noise radiation in agreement with the experimental data. Frequency spectrum prediction exhibited a strong low-frequency tonal contribution at multiples of the blade passing frequency related to the interaction with coherent vortical structures in hover, and a high-frequency broadband hump due to the laminar separation bubble at high advance ratio.

Keywords
Propeller Aerodynamics, Laminar Separation Bubble, Aerodynamic Noise, Lattice-Boltzmann Method, Very-Large-Eddy-Simulation, Confined Aeroacoustics

Published online 11/1/2023, 4 pages
Copyright © 2023 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: Riccardo Colombo, Lorenzo Maria Pii, Gianluca Romani, Maurizio Boffadossi, Predicting noise spectrum of a small drone rotor in a confined environment: a lattice Boltzmann Vles analysis, Materials Research Proceedings, Vol. 37, pp 21-24, 2023

DOI: https://doi.org/10.21741/9781644902813-5

The article was published as article 5 of the book Aeronautics and Astronautics

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] D. Casalino; An advanced time approach for acoustic analogy predictions. Journal of Sound and Vibration, Vol. 261, n. 4, 583-612, 2003. https://doi.org/10.1016/S0022-460X(02)00986-0
[2] D. Casalino, G. Romani, E. Grande, D. Ragni, and F. Avallone; Definition of a benchmark for low reynolds number propeller aeroacoustics. Aerospace Science and Technology, 2020. https://doi.org/10.1016/j.ast.2021.106707
[3] D. Casalino, G. Romani, R. Zhang, and H Chen; Lattice-boltzmann calculations of rotor aeroacoustics in transitional boundary layer regime. AIAA 2022-2862, 2022. https://doi.org/10.2514/6.2022-2862
[4] Hudong Chen, Steven A Orszag, Ilya Staroselsky, and Sauro Succi; Expanded analogy between Boltzmann kinetic theory of fluids and turbulence. Journal of Fluid Mechanics, 519:301–314, 2004. https://doi.org/10.1017/S0022112004001211
[5] E. Grande, G. Romani, D. Ragni, F. Avallone, and D. Casalino; Aeroacoustic investigation of a propeller operating at low Reynolds numbers. AIAA Journal, Vol. 60, No. 2, 2022. https://doi.org/10.2514/1.J060611