Aerodynamic and Aeroacoustic Effects of Swirl Recovery Vanes Length

Avallone, Francesco; Ende, Leonore van den; Li, Q.; Ragni, Daniele; Casalino, Damiano; Eitelberg, G.; Veldhuis, L.L.M.

doi:10.2514/1.c035552

Cited by 12 publications

(3 citation statements)

References 31 publications

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“…The Lattice Boltzmann Method (LBM) is used to compute the flow field because it was shown to be accurate and efficient for similar low Reynolds number rotor applications [32,[43][44][45][46]. The commercial software 3DS Simulia PowerFLOW has been already validated for aerodynamic and aeroacoustic studies on rotors in general [47][48][49]. The software solves the discrete Lattice Boltzmann (LB) equation for a finite number of directions.…”

Section: B Flow Solver -Powerflowmentioning

confidence: 99%

Effect of struts and central tower on aerodynamics and aeroacoustics of vertical axis wind turbines using mid-fidelity and high-fidelity methods

Shubham,

Avallone,

Brandetti

et al. 2024

AIAA SCITECH 2024 Forum

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This study investigates the impact of struts and a central tower on the aerodynamics and aeroacoustics of Darrieus Vertical Axis Wind Turbines (VAWTs) at chord-based Reynolds numbers of 8.12 × 10 4 . A 2-bladed H-Darrieus VAWT is used, featuring a 1.5m diameter, a solidity of 0.1 and a blade cross-section of symmetrical NACA 0021. The turbine design is kept simple and straight-bladed which is essential for isolating and analyzing the specific effects of struts and a tower. The high-fidelity Lattice Boltzmann Method (LBM) in PowerFLOW 6-2020 and the mid-fidelity Lifting Line Free Vortex Wake (LLFVW) method in QBlade 2.0 are employed, with the mid-fidelity method providing a faster analytical tool for insights into the turbine performance. Firstly, both the LLFVW (mid-fidelity) and LBM (high-fidelity) methods effectively capture the general trends observed in VAWT power performance. However, the former predicts mean thrust values that are approximately 10% higher, and mean torque values that are approximately 19% higher, in comparison to the latter. Subsequently, the former predicts lower streamwise wake velocities relative to those predicted by the latter. These differences increase in configurations that include struts and a tower (to 30% -31%). Secondly, the presence of struts and a tower leads to a reduction in both mean power (by 15% to 55%) and thrust (by 3% to 3.6%), with a further small decrease observed when doubling the tower diameter (power and thrust both by 0.5% to 3%). The struts predominantly affect the spanwise distribution of blade loading, while the tower impacts the azimuthal variation of blade loading. Additionally, the addition of struts and a tower reduces low-frequency noise (50-200 Hz) while increasing high-frequency noise (> 300 Hz). The observed decrease in mean blade loading results in reduced low-frequency noise, while the increase in high-frequency noise is ascribed to the increased intensity of BWI/BVI leading to higher unsteady loading fluctuations on blades.

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Section: B Flow Solver -Powerflowmentioning

confidence: 99%

Effect of struts and central tower on aerodynamics and aeroacoustics of vertical axis wind turbines using mid-fidelity and high-fidelity methods

Shubham,

Avallone,

Brandetti

et al. 2024

AIAA SCITECH 2024 Forum

View full text Add to dashboard Cite

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“…The CFD/CAA solver Simulia PowerFLOW 6-2021-R3, based on the Lattice-Boltzmann Method (LBM), is used in this work to compute the flow around the aircraft and to predict the generated noise. Referring to aeroacoustics of rotating parts, this software has already been validated for UAV rotors [8][9][10], aircraft propellers [11] and aero engine fan/OGV stages [12,13].…”

Section: Flight-test Campaignmentioning

confidence: 99%

Aeroacoustic Study of a Twin-turboprop Aircraft Using the Lattice-Boltzmann Method

Grande,

Massarino,

Kroemer

et al. 2024

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

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The present study focuses on the prediction of groundbased tonal noise generated by a twin-turboprop aircraft in cruise flight at different heights, by means of a CFD/CAAbased approach. The unsteady flow solution of the 1:1 scale model is obtained using the Lattice-Boltzmann/Very Large Eddy Simulation method. Numerical predictions are validated against fly-over noise measurements conducted on the entire aircraft. Microphones were positioned both parallel and perpendicular to the flight path, in order to capture the directivity of the aircraft noise. The far-field noise spectra, computed via the Ffowcs-Williams and Hawkings´acoustic analogy applied to the propeller and airframe surfaces, show a good correspondence between the numerical and experimental results at the first and second blade passing frequencies, with a maximum difference of 2 dB. Furthermore, the on-ground noise footprints reveal that the employed method is able to capture the complex acoustic field generated by the propellers and its scattering on the airframe. The latter gives a significant contribution especially outside of the propeller plane, showing the need to simulate the whole configuration for an accurate estimation of the on-ground noise levels.

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“…In total, 13 variable resolution (VR) regions were used based on the ref. [27]. The cell volume changes by a factor of 8 between different VR regions.…”

Section: B Computational Volume and Boundary Conditionsmentioning

confidence: 99%

Aerodynamics and Far-field Noise Emissions of a Propeller in Positive and Negative Thrust Regimes at Non-zero Angles of Attack

Goyal

Sinnige

Ferreira

et al. 2023

AIAA AVIATION 2023 Forum

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This paper studies the effect of operation at non-zero angles of attack on the aerodynamic performance and far-field noise emissions of an isolated propeller operating at positive and negative thrust conditions. To achieve this, scale-resolved lattice-Boltzmann very large eddy simulations coupled with the Ffowcs Williams & Hawkings analogy have been used. The results show that when the propeller operates with a 10 • angle of attack at the positive thrust condition, the blade loading increases on the advancing side and decreases on the retreating side, leading to a 9.6% increase in integrated thrust (when computed along the propeller axis) and a negligible increase (0.1%) in propeller efficiency. Conversely, at the negative thrust condition, the operation at 10 deg angle of attack results in a 7.9% decrease in thrust magnitude and an 11.1% reduction in energy-harvesting efficiency. In this condition, the positively cambered blade sections exhibit dynamic stall at the 10 • angle of attack, resulting in broadband fluctuations of up to 10% of the mean loading. As a result of the opposite change in absolute blade loading in the negative thrust condition compared to the positive thrust condition at the 10 • angle of attack, the change in the noise directivity is also the opposite. Whereas in the positive thrust case, the noise increases in the region from which the propeller is tilted away (i.e., below the propeller at a positive angle of attack), in the negative thrust case, it is the other way around. This study highlights the need to account for non-zero angles of attack in propeller design and optimization analyses. Nomenclature 𝐵 number of propeller blades BPF 𝐵 • 𝑛, blade passing frequency, Hz 𝑐 section chord, m 𝑐 o speed of sound in dry air at 15 • C, m/s

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Aerodynamic and Aeroacoustic Effects of Swirl Recovery Vanes Length

Cited by 12 publications

References 31 publications

Effect of struts and central tower on aerodynamics and aeroacoustics of vertical axis wind turbines using mid-fidelity and high-fidelity methods

Effect of struts and central tower on aerodynamics and aeroacoustics of vertical axis wind turbines using mid-fidelity and high-fidelity methods

Aeroacoustic Study of a Twin-turboprop Aircraft Using the Lattice-Boltzmann Method

Aerodynamics and Far-field Noise Emissions of a Propeller in Positive and Negative Thrust Regimes at Non-zero Angles of Attack

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