Smart Rotors: Dynamic-Stall Load Control by Means of an Actuated Flap

Raiola, Marco; Discetti, Stefano; Ianiro, Andrea; Samara, Farid; Avallone, Francesco; Ragni, Daniele

doi:10.2514/1.j056342

Cited by 18 publications

(16 citation statements)

References 39 publications

(50 reference statements)

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“…To achieve this, 27 differential pressure transducers were used to measure the differential pressure between the suction and pressure side of the airfoil at the same x/c location. This technique was successfully used by Raiola et al [21] on a symmetric airfoil. To validate the technique used on cambered airfoils, a set of experiments were conducted and are discussed in Section II.C.…”

Section: A Wind Tunnel Setupmentioning

confidence: 99%

“…The ccw cycle is due to the nature of dynamic motion and a characteristic of the airfoil. For example, Raiola et al [21] tested a symmetric airfoil, the NACA 0015, under similar conditions and the results show that the hysteresis cycle was clockwise. The NACA 0015 is a symmetric airfoil while the S833 airfoil has camber and is thicker.…”

Section: B Dynamic Pitchingmentioning

confidence: 99%

“…Boutilier and Yarusevych [20] showed that the maximum root-mean-square (RMS) in surface pressure corresponds to a location between the mean transition and reattachment point. Raiola et al [21] was able to determine the transition from the standard deviation (STD) in C p contour plots while the airfoil was pitching.…”

Section: Introductionmentioning

confidence: 99%

“…The TEF was not however capable of controlling the formation and detachment of the LEV but the TEF was capable of controlling the LEV magnitude. Raiola et al [21] showed that a TEF on a NACA0015 airfoil was capable of controlling the loads generated by dynamic stall and the LEV. The literature lacks data about dynamic stall behavior on wind turbine specific airfoils or cambered airfoils in general with surface pressure measurements.…”

Section: Introductionmentioning

confidence: 99%

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Dynamic Stall on Pitching Cambered Airfoil with Phase Offset Trailing Edge Flap

Samara

Johnson

2020

AIAA Journal

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Dynamic stall on wind turbine blades often leads to severe fatigue that tends to decrease the lifespan of the blades. To mitigate cyclic loading on the blades, trailing edge flaps (TEF) may be used to control the energy captured by the blades. In this study the influence of a TEF on a pitching S833 cambered airfoil is investigated at a Reynolds number of 170,000 and reduced frequencies of k = 0.06 and 0.1. The lift and moment hysteresis cycles are presented for mean pitch angles of 0 • and 10 • to represent stall onset and deep stall. The flap, hinged at 0.8 chord, is pitching with different phase lags to study the influence of flap motion. Coefficient of pressure contour plots presented here, clearly indicate the leading edge vortex (LEV) formation and convection. It is concluded that even though the TEF was not capable of controlling the

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Section: A Wind Tunnel Setupmentioning

confidence: 99%

Section: B Dynamic Pitchingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dynamic Stall on Pitching Cambered Airfoil with Phase Offset Trailing Edge Flap

Samara

Johnson

2020

AIAA Journal

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“…So far, active flow control methods for dynamic stall have become research hotspots. The widely investigated methods mainly include plasma actuators [6][7][8], synthetic jet [9,10], blowing [11][12][13], dynamically deformable leading edge (DDLE) [14], and trailing edge flap [15][16][17][18]. Most of the research on plasma actuators are limited to results obtained under low speed and low Reynolds number conditions.…”

Section: Introductionmentioning

confidence: 99%

Inflatable Leading Edge-Based Dynamic Stall Control considering Fluid-Structure Interaction

Xing

et al. 2020

International Journal of Aerospace Engineering

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The inflatable leading edge (ILE) is explored as a dynamic stall control concept. A fluid-structure interaction (FSI) numerical method for the elastic membrane structure is constructed based on unsteady Reynolds-averaged Navier-Stokes (URANS) and a mass-spring-damper (MSD) structural dynamic model. Radial basis function- (RBF-) based mesh deformation algorithm and Laplacian and optimization-based mesh smoothing algorithm are adopted in flowfield simulations to achieve the pitching oscillation of the airfoil and to ensure the mesh quality. An airfoil is considered at a freestream Mach number of 0.3 and chord-based Reynolds number of 3.92×106. The airfoil is pitched about its quarter-chord axis at a sinusoidal motion. The numerical results indicate that the ILE can change the radius of curvature of the airfoil leading edge, which could reduce the streamwise adverse pressure gradient and suppress the formation of dynamic stall vortex (DSV). Although the maximum lift coefficient of the airfoil is slightly reduced during the control process, the maximum drag and pitching moment coefficients of the airfoil are greatly reduced by up to 66% and 75.2%, respectively. The relative position of the ILE has a significant influence on its control effect. The control laws of inflation and deflation also affect the control ability of the ILE.

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