Effect of Steady Blowing on Wing Tip Flowfield

Margaris, P; Gursul, Ismet

doi:10.2514/6.2004-2619

Cited by 13 publications

(15 citation statements)

References 6 publications

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“…A wing was simulated at 10 • angle of attack in steady flow conditions to demonstrate the application of this method to a 3D case and assess the validity of the wake generated. This case is based on the experiments of Margaris and Gursul [27] and the PIV data from these experiments are used for comparison. The wing has a NACA 0015 profile with an aspect ratio of 5.08 and the experiments were performed at Re ≈ 10 5 based on freestream velocity and chord length.…”

Section: Steady-state Wingmentioning

confidence: 99%

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Coupling of an Unsteady Aerodynamics Model with a Computational Fluid Dynamics Solver

et al. 2018

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Coupling of an unsteady aerodynamics model with a computational fluid dynamics solver. Momentum source methods are an efficient means of representing airfoils in Navier-Stokes CFD simulations. Momentum source terms are added to the Navier-Stokes equations instead of resolving the solid boundary of the airfoil with a mesh. These source terms are calculated using an aerodynamics model. This approach is useful where the overall performance and midto far-field influence of a wing or rotor are desired and details of the flow field near the blade are not the objective of the simulation. One example is simulation of rotorcraft operations where the objective may be to assess an operation's feasibility in terms of control margins, rather than to inform rotor design decisions. Coupling an aerodynamics model to a CFD solver is straightforward in cases where the airflow relative to the blade is steady. Unsteady conditions require an unsteady aerodynamics model, complicating the coupling with the CFD solver. A coupling method is proposed whereby the incident velocity is extracted from the CFD solution and corrected using a theory based approximation for the unsteady induced velocity. The steady-state momentum source method is demonstrated for 2D and 3D simulations and the unsteady coupling method is validated against experiments on a pitching airfoil and verified for blade-vortex interactions. The unsteady coupling method enables meaningful incident velocities to be extracted from unsteady flow-fields, as shown by agreement with experiments and simulations using analytical expressions for the incident velocity in place of the CFD solver.

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Section: Steady-state Wingmentioning

confidence: 99%

“…The locations of the PIV planes in the experiment are shown in Figure 11 along with the coordinate systems used. [27] for the finite aspect ratio wing with NACA 0015 profile.…”

Section: Steady-state Wingmentioning

confidence: 99%

Coupling of an Unsteady Aerodynamics Model with a Computational Fluid Dynamics Solver

et al. 2018

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“…Lee et al [8,9] showed that a lateral blowing might generate a secondary vortex at a certain instance, and the displacement of vortex depends on the different ways of blowing, that is, blowing angle, blowing, and flux. Margaris and Gursul [10] conducted their experiment on a rectangular wing using different blowing slots and found that blowing toward the lower surface of the wing could produce a pair of co-rotating vortex, which accelerated the dissipation of vortices and decreased the induced drag. Margaris and Gursul [11] further studied the influence of the tip shape and longitudinal position of the slot on the wing tip vortex.…”

Section: Introductionmentioning

confidence: 98%

Wing tip vortex structure behind an airfoil with flaps at the tip

Yang

2011

Sci. China Phys. Mech. Astron.

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In this work, the wing tip vortex structure behind a NACA 0015 airfoil with and without small flaps was studied using a Partical Image Velocimetry (PIV) system. The experiment was carried out in a low speed wind tunnel with a test section of 0.5 m × 0.5 m. The Reynolds number (Re), defined by the chord length of the wing (C), was 8.1×10 4 . The angle of attack was fixed at 10°. The PIV measurements were made from 0 to 2C, measured from the trailing edge of the model. The dihedral angle of three flaps was 15°, 0° and 15°, respectively. Compared with the clean airfoil, the one with three flaps significantly changed the wing tip vortex structure, the vorticity and the core of the wing tip vortex. The occurrence of three flaps decreased the gradient of pressure on the two sides of the wing tip, which depressed wing tip vortex formation to some extent. Vortices shed from three flaps influence the evolution of the wingtip vortex generated by the base airfoil. The interaction of those vortices resulted in a weakening of the wing tip vortex. wing tip vortex, flap, PIV PACS: 98.70.Sa, 90.50.sb, 13.85.Tp

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“…Using steady air blowing at the tip to perturb the forming vortex is an attractive strategy because of the availability of engine bleed air used for wing de-icing at cruise. Previous studies 8,9,10,11 have all shown that spanwise blowing from slots in the wing tip can improve the wing's aerodynamic performance by creating an effective increase in aspect ratio with the by-product that the tip vortex is pushed outwards and generally upwards. The results showed a great sensitivity of the near field to the blowing configuration and blowing coefficient, whereas, some configurations resulted in a more coherent structure of the vortex.…”

Section: Introductionmentioning

confidence: 99%

Control of Wing Tip Vortex Structure Using Fluidic Actuation

Dghim

Ferchichi

BenChiekh

2014

7th AIAA Flow Control Conference

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The development of a wing tip vortex under the effect of synthetic jet actuation was examined qualitatively using Laser smoke flow visualization and qualitatively using hot-wire anemometry at a chord Reynolds number, , of 80 000. Fluidic excitation was found to alter the formation of the wing tip vortex by reducing the axial vorticity by nearly 30% which resulted in a decreased cross-flow velocity and consequently an increased diffusion in the lateral direction outward the vortex center. The turbulence measured within the vortex core was found to intensify near the vortex center when the synthetic jet was operated which resulted in enhanced mixing and accelerated diffusion of the vortex as it developed downstream. Results of flow visualizations show that the wing tip vortex appeared to be responsive to low actuation frequencies and that turbulent diffusion in the vortex core was more pronounced at higher momentum coefficients. Downloaded by KUNGLIGA TEKNISKA HOGSKOLEN KTH on July 30, 2015 | http://arc.aiaa.org | ̅= Streamwise vorticity, = Radial distance from mean vortex axis, = Streamwise distance from wing quarter-chord location, = Spanwise direction distance from vortex center, = Vertical direction distance from vortex center, = Spanwise distance separating two measurement grid points in the direction, = Transcerse distance separating two measurement grid points in the direction,

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Effect of Steady Blowing on Wing Tip Flowfield

Cited by 13 publications

References 6 publications

Coupling of an Unsteady Aerodynamics Model with a Computational Fluid Dynamics Solver

Coupling of an Unsteady Aerodynamics Model with a Computational Fluid Dynamics Solver

Wing tip vortex structure behind an airfoil with flaps at the tip

Control of Wing Tip Vortex Structure Using Fluidic Actuation

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