Aspect-Ratio Effects for Low-Order Modeling of Swept-Wing Stall

2018 ◽  
Author(s):  
Abhimanyu Jamwal ◽  
Pranav Hosangadi ◽  
Ashok Gopalarathnam
Keyword(s):  
Aspect Ratio ◽  
Swept Wing ◽  
Wing Stall ◽  
Low Order

Effect of Aspect Ratio on Swept Wing Dynamic Stall

2021 ◽  
Author(s):  
Patrick R. Hammer ◽  
Daniel J. Garmann ◽  
Miguel R. Visbal
Keyword(s):  
Aspect Ratio ◽  
Dynamic Stall ◽  
Swept Wing

The Effect of Structural Geometric Nonlinearities on the Flutter of the Straight and Swept Wing Configurations

2012 ◽  
Vol 189 ◽  
pp. 306-311 ◽  
Author(s):  
Qing Guo ◽  
Bi Feng Song
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Swept Wing ◽  
Geometric Nonlinearities ◽  
Air Vehicle ◽  
Structural Nonlinearity ◽  
Flutter Analysis ◽  
Long Endurance ◽  
The Impact ◽  
Straight Wing

High altitude and long endurance (HALE) vehicle always adopt straight or swept configuration, which leads to the problem that the wings of UAV have high aspect ratio and are very flexible. This kind of flexible wing exhibits large deformation when aerodynamic forces are loaded on them and the structural nonlinearity should be considered. So the dynamic and flutter characteristics will be changed. In the engineering applications, the effects of structural geometric nonlinearities on the air vehicle design are the most concerns of aeroelasticity before a systematic flutter analysis for the air vehicle. because the solution for nonlinear flutter speed based on the CFD-CSD method is complex and time consuming. In this paper, we propose a simple and efficient approach that can analyze the effect of structural geometric nonlinearities on the flutter characteristics of high aspect ratio wing quickly. And a straight wing and a straight-swept wing are analyzed to verify the feasibility and efficiency of the proposed method. It is found that the effect of structural geometric nonlinearities has a strong effect on the flutter characteristic of the straight wing, but is weak on the straight-swept wing. And finally the impact of swept angle on the dynamic and flutter characteristics of straight-swept wing is also discussed.

scholarly journals Numerical Investigation into Flutter and Flutter-Buffet Phenomena for a Swept Wing and a Curved Planform Wing

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Mario Rosario Chiarelli ◽  
Salvatore Bonomo
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
High Speed ◽  
Sensitivity Study ◽  
Fuel Saving ◽  
Swept Wing ◽  
Instability Condition ◽  
Aspect Ratios ◽  
Numerical Studies ◽  
Classical Flutter

The results of numerical studies carried out on high-aspect-ratio wings with different planforms are discussed: the transonic regime is analysed for a swept wing and a curved planform wing. The wings have similar aspect ratios and similar aerodynamic profiles. The analyses were carried out by CFD and FE techniques, and the reliability of the numerical aerodynamic results was proven by a sensitivity study. Analysing the performances of the two wings demonstrated that in transonic flight conditions, a noticeable drag reduction can be obtained by adopting a curved planform wing. In addition, for such a wing, the aeroelastic instability condition, consisting in a classical flutter, is postponed compared to a conventional swept wing, for which a flutter-buffet instability occurs. In a preliminary manner, the study shows that, for a curved planform wing, the high speed buffet is not an issue and at the same time notable fuel saving can be achieved.

Low-order Aeroelastic Modelling of a High Aspect Ratio Wing Aircraft Under Constrained Motion

2022 ◽  
Author(s):  
Alessandro Pontillo ◽  
Punsara D. Banneheka Navaratna ◽  
James Ascham ◽  
Mark H. Lowenberg ◽  
Djamel Rezgui ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Constrained Motion ◽  
Low Order

Pitching effect on transonic wing stall of a blended flying wing with low aspect ratio

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840040
Author(s):  
Yang Tao ◽  
Zhongliang Zhao ◽  
Junqiang Wu ◽  
Zhaolin Fan ◽  
Yi Zhang
Keyword(s):  
Shock Wave ◽  
Aspect Ratio ◽  
Stokes Equations ◽  
Vortex Breakdown ◽  
Great Influence ◽  
Second Order ◽  
Upwind Scheme ◽  
Detached Eddy Simulation ◽  
Low Aspect Ratio ◽  
Wing Stall

Numerical simulation of the pitching effect on transonic wing stall of a blended flying wing with low aspect ratio was performed using improved delayed detached eddy simulation (IDDES). To capture the discontinuity caused by shock wave, a second-order upwind scheme with Roe’s flux-difference splitting is introduced into the inviscid flux. The artificial dissipation is also turned off in the region where the upwind scheme is applied. To reveal the pitching effect, the implicit approximate-factorization method with sub-iterations and second-order temporal accuracy is employed to avoid the time integration of the unsteady Navier–Stokes equations solved by finite volume method at Arbitrary Lagrange–Euler (ALE) form. The leading edge vortex (LEV) development and LEV circulation of pitch-up wings at a free-stream Mach number M = 0.9 and a Reynolds number Re = [Formula: see text] is studied. The Q-criterion is used to capture the LEV structure from shear layer. The result shows that a shock wave/vortex interaction is responsible for the vortex breakdown which eventually causes the wing stall. The balance of the vortex strength and axial flow, and the shock strength, is examined to provide an explanation of the sensitivity of the breakdown location. Pitching motion has great influence on shock wave and shock wave/vortex interactions, which can significantly affect the vortex breakdown behavior and wing stall onset of low aspect ratio blended flying wing.

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