Noise Source Analysis in Counter-Rotating Open Rotors

Smith, Dale; Filippone, Antonio; Barakos, George N.

doi:10.2514/1.j060886

Cited by 8 publications

(5 citation statements)

References 55 publications

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“…The source values to be regularised are based on the local sectional lift 𝐿 and sectional drag 𝐷 of the blade airfoil sections, determined from the flow kinematics in the sectional plane shown in Fig. (7), where 𝐿 and 𝐷 are defined in the aerodynamic coordinate system which is obtained by rotating the −𝑥 and −𝐴𝑧𝑖𝑚 axis by the angle 𝜙 of the vector of the inflow velocity 𝑞 at the airfoil. The angle of attack 𝛼 of the chord relative to 𝑞 is obtained as:…”

Section: B Model Based On Blade Element Momentum Theorymentioning

confidence: 99%

“…Other authors presented similar tool-chains based on coupled URANS-FWH methods, with comparable positive outcomes. In [7] an approach was presented based on results of a computational tool-chain including URANS simulations as a background mean flow for the acoustics prediction based on the FWH formulation 1A of Farassat. A clear distinction between noise sources' components in the Farassat formulation is assumed for the rotors configurations selected.…”

Section: Introductionmentioning

confidence: 99%

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Fast Non-Empiric Tonal Noise Prediction Model for Installed Propulsors

Franco

Moessner

Ewert

et al. 2022

28th AIAA/CEAS Aeroacoustics 2022 Conference

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The increasing demand for cuts in environmental pollution is driving aircraft manufacturers towards sustainable aviation concepts that integrate unconventional propulsion configurations on the airframe. To aid the design process of new aircraft, a reliable prediction of installed rotor noise emissions would be required. Therefore, in this work an advanced rotor noise prediction approach is presented, which was developed to be fast and physical-principles-based, in order to be able to represent current and possibly newly arising noise sources mechanisms in complex configurations. The tool-chain proposed relies on aerodynamic predictions based on Actuator Disc (AD) Reynolds Averaged Navier Stokes (RANS) computations that provide the background flow solution for the Computational Aeroacoustics (CAA) method, which considers Gaussian regularised line-source distributions of strengths defined from either the obtained AD surface loads solution, or tabulated aerodynamic data used in combination with a model based on Blade Element Momentum Theory (BEMT). In this work initial successful results are reported for simplified test cases, outlining future possible applications.

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Section: B Model Based On Blade Element Momentum Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fast Non-Empiric Tonal Noise Prediction Model for Installed Propulsors

Franco

Moessner

Ewert

et al. 2022

28th AIAA/CEAS Aeroacoustics 2022 Conference

View full text Add to dashboard Cite

show abstract

“…Even so, the use of additional sound insulation and active noise suppression systems for the cabin might be required for optimal passenger comfort ( Smith, 2016 ; Jupp, 2016a ). Nonetheless, recent studies making use of advanced computational fluid dynamic tools have made advances indicating that it is possible to significantly reduce the noise generated by open rotor engines by optimizing the configuration and shapes of their blades ( Smith et al, 2021 ; Jaron et al, 2018 ).…”

Section: Green Technologies For Conventional Aircraft Projectsmentioning

confidence: 99%

Emissions of future conventional aircrafts adopting evolutionary technologies

Bravo

Vieira

Ferrer

2022

Journal of Cleaner Production

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“…Common features hence exist in the generation of noise with sources of tonal and broadband noise described above. Despite such similarities, propellers may be subjected to additional interaction noise resulting from the wake of a pylon impinging the blades in pusher configuration 9 and from the wake of the fore propeller impinging the aft propeller (referred to as rotors in some cases) in counter-rotating open rotor (CROR) configurations, 10,11 for example. In the latter case, wake-blade interaction usually comprises two components: the tip-vortex interaction noise and the potential-field interaction noise.…”

Section: Introductionmentioning

confidence: 99%

Numerical and experimental analysis of the influence of solidity on rotor aeroacoustics at low Reynolds numbers

Jardin

Gojon

Doué

et al. 2023

International Journal of Aeroacoustics

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We compare medium and high fidelity numerical simulations to experiments conducted on low Reynolds number rotors typical of small scale Unmanned Aircraft Systems (UAS). We first show that these numerical approaches provide reasonable estimates of the aerodynamic performance and farfield tonal noise and hence apply them for the investigation of the influence of solidity ratio on the aerodynamics and acoustics of small scale rotors operating under hovering, iso-thrust conditions. We show that while solidity ratio has a weak impact on aerodynamic performance, it may help drastically reduce farfield tonal noise. This reduction is however found to depend on the interplay between thickness and loading noise such that increasing the solidity by increasing the number of blades at constant blades’ aspect ratio or by decreasing the blades’ aspect ratio keeping the number of blades constant may yield very different, sometimes opposite, trends.

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Noise Source Analysis in Counter-Rotating Open Rotors

Cited by 8 publications

References 55 publications

Fast Non-Empiric Tonal Noise Prediction Model for Installed Propulsors

Fast Non-Empiric Tonal Noise Prediction Model for Installed Propulsors

Emissions of future conventional aircrafts adopting evolutionary technologies

Numerical and experimental analysis of the influence of solidity on rotor aeroacoustics at low Reynolds numbers

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