Dipole source-based virtual three-dimensional imaging for propeller noise

Chen, Wangqiao; Jiang, Hanbo; He, Weishu

doi:10.1016/j.ast.2022.107562

Cited by 11 publications

(4 citation statements)

References 33 publications

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“…In this section, the theoretical background and derivations for the numerical beamforming and the proposed near-field aeroacoustic source analysis are given. The former technique is not new in experiments but became available to the numerical community only recently (Fleury & Chélius 2013;Horváth, Envia & Podboy 2014;Ma 2017;Chen et al 2022) owing to the great advances in computational capability. The latter technique is a new approach proposed in this work in reaction to certain inadequacies (such as low reconstruction resolution and complexity in the feedforward reconstruction model) of the former.…”

Section: Sources Analysis Methodsmentioning

confidence: 99%

“…The first is the aforementioned resolution limitation. Second, beamforming needs an a priori hypothesis of point sources, which are usually equivalent monopole (Sijtsma 2006) or dipole (Chen et al 2022) sources, while the practical aeroacoustic sources could be of multiple types simultaneously. Third, when applied to numerical data, beamforming still makes use of the noise signals from finite microphone arrays, as was used originally in the experiments.…”

Section: Comparison Of Source Analysis Methodsmentioning

confidence: 99%

“…(2020 a ) have performed particle image velocimetry (PIV) measurements to acquire the flow field, and conducted wavelet-based beamforming to capture the moving sources from a propeller ingesting aerofoil wakes, which show consistency of source generation with the interaction flow phenomenon. More recently, by using acoustic signals sampled from various artificial microphone arrays on different planes, Chen, Jiang & He (2022) have provided a three-dimensional acoustic imaging technique for the study of propeller noise. However, the above works on smaller-size rotors hardly provide imaging results at frequencies lower than 1 kHz due to the resolution issue.…”

Section: Introductionmentioning

confidence: 99%

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Aeroacoustic sources analysis of wake-ingesting propeller noise

Yangzhou

et al. 2023

J. Fluid Mech.

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High resolution aeroacoustic source analysis is a prerequisite to address the noise concerns and release the full benefits of wake-ingesting propellers. In this work, the aeroacoustic sources of a two-bladed propeller ingesting the wake of an aerofoil are investigated using large eddy simulation in conjunction with two different source identifying approaches. The first approach is the numerical beamforming that utilizes both the classical and wavelet-based beamforming techniques, which determine the phase variations of sources at the low to mid frequencies and reveal that the high-frequency sources are phase-independent. To further improve the spatial resolution of source identification, a new near-field aeroacoustic source analysis approach based on the acoustic analogy is developed in this work. In particular, the on-surface source terms emanating the far-field noise are derived based on the Ffowcs Williams and Hawkings equation for low Mach number flows and constant rotating propellers. Through the incorporation of the simulation results into the proposed source analysis approach, various types of aeroacoustic sources are identified and studied by visualizing their distributions on the propeller surfaces, correlating to flow features and examining the noise spectra and directivity. While the leading edge sources are highly correlated with the wake interaction process, the sources at the mid-chord and the trailing edge of the blade can maintain their strength across most revolving angles. Overall, the proposed analysis approaches extend the capability of computational fluid dynamics and enable the detailed study of noise generation mechanisms of wake-ingesting propeller noise.

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Section: Sources Analysis Methodsmentioning

confidence: 99%

Section: Comparison Of Source Analysis Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Aeroacoustic sources analysis of wake-ingesting propeller noise

Yangzhou

et al. 2023

J. Fluid Mech.

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show abstract

“…Recently, Pan et al, [32] developed a beamforming correction method in the frequency domain to identify rotating loading sources. Chen et al, [33] proposed a beamforming method in the time-frequency domain based on a moving dipole source formulation and obtained acoustic imaging results at different frequencies from an array located on the side of a propeller. However, a significant drawback of the beamforming methods is that it fails to quantify the source strengths accurately when multiple coherent sources are present.…”

Section: Introductionmentioning

confidence: 99%