Aerodynamic performance of morphing and periodic trailing edge morphing aerofoils in ground effect
Aerodynamic performance of morphing and periodic trailing edge morphing aerofoils in ground effect
Applying fish bone active camber morphing to the wing-in-ground effect to improve the aerodynamic efficiency was investigated using computational fluid dynamics (CFD) at a Reynolds number of 320,000. Steady-static morphing was first carried out with Reynolds-averaged Navier–Stokes (RANS) equations in two dimensions for morphing start locations off (60%, 80%, and 90% chord), ground clearances (h/c=0.1
, 0.2, 0.4, 1), and angles of attack (AoAs) 0°, 2°, 3°, 4°, and 12°. A morphing displacement (wte
) of 0.5% increased the efficiency by 2.8% (compared to non-morphing in the ground effect) for the 3° AoA and 90% start location, and by 62% in comparison to the baseline unmorphed airfoil in freestream. Reducing h/c=1
to 0.1 increased the lift between 10% and 17%; the larger gain was with the highest morphing deflection. A key finding was that morphing the airfoil reduced the distance between the trailing edge and ground, enhancing the ground effect. Also, morphing at an earlier start location in the chord direction resulted in a smaller area beneath the airfoil, reducing the total pressure, which reduced the overall lift compared to a later morphing start location. Dynamic morphing at 1 Hz using URANS K-Omega-SST showed a similar amount of lift as static morphing but a slightly higher amount of drag. Reducing the period caused an initial overshoot in drag before settling. The dynamic ground effect showed higher efficiency at low AoAs compared to dynamic morphing in freestream, which is beneficial for aircraft to fly with less pitch. Finally, periodic morphing for h/c=0.1 using sinusoidal motion with morphing starting at 25% along the chord and 4° AoA was investigated between 0.05% to 0.15% wte and 0.5 to 3.5 Strouhal number. Periodically morphing at 0.125% wte and Strouhal number of 0.9 using DES simulations increased the efficiency by 5.4%; however, it reduced the lift by 0.7%, the drag reduced by 5.8%, and it showed Kelvin–Helmholtz instability at 9.8 Strouhal number.
Computational fluid dynamics (CFD), Dynamic and periodic morphing, Ground effect, Morphing wings
Clements, Dominic
878a9bfa-ad41-42b5-b4e0-f773c74ec652
Djidjeli, Kamal
94ac4002-4170-495b-a443-74fde3b92998
1 May 2023
Clements, Dominic
878a9bfa-ad41-42b5-b4e0-f773c74ec652
Djidjeli, Kamal
94ac4002-4170-495b-a443-74fde3b92998
Clements, Dominic and Djidjeli, Kamal
(2023)
Aerodynamic performance of morphing and periodic trailing edge morphing aerofoils in ground effect.
Journal of Aerospace Engineering, 36 (3), [04023012].
(doi:10.1061/JAEEEZ.ASENG-4707).
Abstract
Applying fish bone active camber morphing to the wing-in-ground effect to improve the aerodynamic efficiency was investigated using computational fluid dynamics (CFD) at a Reynolds number of 320,000. Steady-static morphing was first carried out with Reynolds-averaged Navier–Stokes (RANS) equations in two dimensions for morphing start locations off (60%, 80%, and 90% chord), ground clearances (h/c=0.1
, 0.2, 0.4, 1), and angles of attack (AoAs) 0°, 2°, 3°, 4°, and 12°. A morphing displacement (wte
) of 0.5% increased the efficiency by 2.8% (compared to non-morphing in the ground effect) for the 3° AoA and 90% start location, and by 62% in comparison to the baseline unmorphed airfoil in freestream. Reducing h/c=1
to 0.1 increased the lift between 10% and 17%; the larger gain was with the highest morphing deflection. A key finding was that morphing the airfoil reduced the distance between the trailing edge and ground, enhancing the ground effect. Also, morphing at an earlier start location in the chord direction resulted in a smaller area beneath the airfoil, reducing the total pressure, which reduced the overall lift compared to a later morphing start location. Dynamic morphing at 1 Hz using URANS K-Omega-SST showed a similar amount of lift as static morphing but a slightly higher amount of drag. Reducing the period caused an initial overshoot in drag before settling. The dynamic ground effect showed higher efficiency at low AoAs compared to dynamic morphing in freestream, which is beneficial for aircraft to fly with less pitch. Finally, periodic morphing for h/c=0.1 using sinusoidal motion with morphing starting at 25% along the chord and 4° AoA was investigated between 0.05% to 0.15% wte and 0.5 to 3.5 Strouhal number. Periodically morphing at 0.125% wte and Strouhal number of 0.9 using DES simulations increased the efficiency by 5.4%; however, it reduced the lift by 0.7%, the drag reduced by 5.8%, and it showed Kelvin–Helmholtz instability at 9.8 Strouhal number.
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Submitted date: 22 July 2022
Accepted/In Press date: 12 December 2022
e-pub ahead of print date: 28 February 2023
Published date: 1 May 2023
Additional Information:
Funding Information:
This work was supported by the Engineering and Physical Sciences Research Council. The authors acknowledge the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton, in the completion of this work.
Publisher Copyright:
© 2023 American Society of Civil Engineers.
Keywords:
Computational fluid dynamics (CFD), Dynamic and periodic morphing, Ground effect, Morphing wings
Identifiers
Local EPrints ID: 471604
URI: http://eprints.soton.ac.uk/id/eprint/471604
ISSN: 0893-1321
PURE UUID: 940803d3-7f33-4e04-98ba-d0761da47246
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Date deposited: 14 Nov 2022 18:06
Last modified: 30 Oct 2023 02:58
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Author:
Dominic Clements
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