Unsteady Separation Control for Wind Turbine Applications at Full Scale Reynolds Number

Cerretelli, Ciro; Gharaibah, Emad; Toplack, Georg; Gupta, Anurag; Wuerz, Werner

doi:10.2514/6.2009-380

Cited by 20 publications

(5 citation statements)

References 9 publications

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“…In recent years, significant aerodynamic improvements were achieved with the type of actuators shown in Figure 1b by controlling flow separation over the flap of several two-dimensional (NACA 0015 [2,53,54] , NACA 0021 [56] , V-22 airfoil [37] , diffuser model [36] , DU96 airfoil [55] , and ADVINT airfoil [58][59][60] ) and three-dimensional models (finite wing and 1/10 th scale, powered V-22 model [37] , and a -wing configuration [57] ).…”

Section: Introductionmentioning

confidence: 99%

“…Several active and passive concepts to provide the oscillatory character of the emitted jet have been proposed, including selfinduced feedback [43] and external control [42,[44][45][46][47] designs. Early actuators for flow control used a splitter in the outlet nozzle [36,40,55] , which forced the jet to exit through discrete outlets ( Figure 1a) instead of having a continuous sweeping range ( Figure 1b). …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Parameters Governing Separation Control with Sweeping Jet Actuators

Woszidlo

2011

29th AIAA Applied Aerodynamics Conference

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Parameters Governing Separation Control with Sweeping Jet Actuators

Woszidlo

2011

29th AIAA Applied Aerodynamics Conference

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“…3 The capabilities of AFC have been demonstrated on airplane and component models in many laboratory and/or aerodynamic environments. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Rathay et al 4,5 applied synthetic jet actuators to a subscale (~7%) vertical stabilizer model, where actuators placed next to the hinge of the rudder produced up to 20% side force increase at moderate rudder deflections. Seele et al 6,7 applied the sweeping jet actuators to a subscale (~14%) vertical tail model.…”

Section: Afcmentioning

confidence: 99%

Flow Separation Control on a Full-Scale Vertical Tail Model using Sweeping Jet Actuators

Andino

Lin

Washburn

et al. 2015

53rd AIAA Aerospace Sciences Meeting

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This paper describes test results of a joint NASA/Boeing research effort to advance Active Flow Control (AFC) technology to enhance aerodynamic efficiency. A full-scaleBoeing 757 vertical tail model equipped with sweeping jets AFC was tested at the National Full-Scale Aerodynamics Complex 40-by 80-Foot Wind Tunnel at NASA Ames Research Center. The flow separation control optimization was performed at 100 knots, a maximum rudder deflection of 30°, and sideslip angles of 0° and -7.5°. Greater than 20% increments in side force were achieved at the two sideslip angles with a 31-actuator AFC configuration. Flow physics and flow separation control associated with the AFC are presented in detail. AFC caused significant increases in suction pressure on the actuator side and associated side force enhancement. The momentum coefficient (C µ ) is shown to be a useful parameter to use for scaling-up sweeping jet AFC from sub-scale tests to full-scale applications. Reducing the number of actuators at a constant total C µ of approximately 0.5% and tripling the actuator spacing did not significantly affect the flow separation control effectiveness. NomenclatureAFC = active flow control APU = auxiliary power unit c = total local chord length CFD = computational fluid dynamics C p = pressure coefficient C y = side force coefficient C Yn = normalized side force coefficient relative to baseline (AFC off) C µ = momentum coefficient, % ERA = Environmentally Responsible Aviation LE = leading edge M ∞ = free stream Mach number NFAC = National Full-Scale Aerodynamics Complex Re = Reynolds number based on mean aerodynamic chord U ∞ = free stream velocity, knots x = streamwise direction β = sideslip angle, degrees δ Rudder = flap deflection angle, degrees %ΔC y = % difference in C y with respect to AFC off, 100%*(C y -C y, AFC off )/ C y, AFC off Downloaded by UNIVERSITY OF TORONTO on July 31, 2015 | http://arc.aiaa.org |

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“…As it became clearer that fluidics could not keep pace with electronics development, it was largely abandoned [15]. Today, its main developments concern flow control for aerodynamic applications [16][17][18]. Nonetheless, the advantages of fluidic technology that drove their development in the past remain valid: Since the functions of fluidic devices are driven by fluid flow within static solid boundaries without electronics, they are virtually maintenance free, robust against shock and vibration, and operable in harsh environments, including those with extreme temperatures or radioactivity [14].…”

Section: Fluidic Transducermentioning

confidence: 99%

OsciCheck: A Novel Fluidic Transducer for Air-Coupled Ultrasonic Measurements

Bühling¹,

Maack²,

Strangfeld³

2022

eJNDT

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Ultrasonic measurement technology has become indispensable in NDT-CE. Air-coupled ultrasonic (ACU) measurement techniques promise to reduce measurement time. However, the signal quality suffers from large specific impedance mismatch at the transducer-air and air-specimen interface. Additionally, large pressure amplitudes are necessary for the penetration depth required in NDT-CE applications. To address the specific requirements of ultrasonic testing in NDT-CE, a robust ACU transducer was developed, that generates ultrasound by quickly switching a pressurized air flow. The simple design of the fluidic transducer makes the device maintenance free and resilient against harsh environmental conditions. Since the signal is generated by aeroacoustics, there is no specific impedance mismatch between the transducer and the surrounding air. The ultrasonic signal exhibits frequencies in the 30-60 kHz range and is therefore well suited to penetrate heterogenous materials such as concrete. This contribution gives an introduction in the working principle and signal characteristics of the fluidic transducer. Its application on different materials is validated. A detailed outlook is given to discuss the future potential of fluidic ultrasonic actuators.

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Unsteady Separation Control for Wind Turbine Applications at Full Scale Reynolds Number

Cited by 20 publications

References 9 publications

Parameters Governing Separation Control with Sweeping Jet Actuators

Parameters Governing Separation Control with Sweeping Jet Actuators

Flow Separation Control on a Full-Scale Vertical Tail Model using Sweeping Jet Actuators

OsciCheck: A Novel Fluidic Transducer for Air-Coupled Ultrasonic Measurements

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