Control of Flow Structure over a Nonslender Delta Wing Using Periodic Blowing

Çetin, Cenk; Çelik, Alper; Yavuz, Mehmet Metin

doi:10.2514/1.j056099

Cited by 14 publications

(7 citation statements)

References 42 publications

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“…Mitchell et al [43] moved the vortex breakdown location downward as 20% of wing chord length utilizing along the core blowing. Several studies were dedicated to control the flow structure over delta wings by periodic blowing from the leading edge [44], [45], and periodic blowing and suction [46]- [48]. respectively.…”

Section: Vortex Breakdownmentioning

confidence: 99%

Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing

Ghazijahani

Yavuz

2019

Aerospace Science and Technology

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, 84 pages Flow characterization over delta wings have gained attention in recent decades due to their prevailing usage in designs of unmanned air vehicles (UAVs). In literature, only a few studies have reported wing thickness effect on both the aerodynamic performance and detailed flow structure over delta wings. In the present investigation, the effect of thickness-to-chord (/) ratio on aerodynamics of a non-slender delta wing with 45 degree sweep angle is characterized in a low-speed wind tunnel using laser illuminated smoke visualization, surface pressure measurements, particle image velocimetry, and force measurements. The delta wings with / ratios varying from 2 % to 15 % are tested at broad ranges of angle of attack and Reynolds number. The results indicate that the effect of / ratio on flow structure is quite substantial. Considering the low angles of attack where the wings experience leading edge vortex structure, the strength of the vortex structure increases as the / ratio increases. However, low / ratio wings have pronounced surface separations at higher angle of attack compared to the high / ratio wings. These results are well supported by the force measurements such that high / ratio wings induce higher lift coefficients, CL, at vi low angles of attack, whereas maximum CL values are higher and appear at higher angle of attack for low / ratio wings. This indicates that low / ratio wings are more resistive to the stall condition. Considering the lift-to-drag ratio, CL/CD, increase in / ratio induces remarkable drop in CL/CD values.

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Section: Vortex Breakdownmentioning

confidence: 99%

Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing

Ghazijahani

Yavuz

2019

Aerospace Science and Technology

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“…It is seen that the effect of the excitation is small for pre-stall angles of attack ( = 15) where there is already reattachment for the baseline flow. control, such as synthetic jets [30] and pulsed jets [29,47,48]. An interesting passive control mechanism has been observed for flexible nonslender delta wings [49] where the periodic excitation (wing leading-edge vibrations) is produced as a result of the fluid-structure interaction.…”

Section: A Control Of Delta Wing Vorticesmentioning

confidence: 99%

Flow Control of Tip/Edge Vortices

Gursul

Wang

2018

AIAA Journal

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Location, strength and structure of tip and edge vortices shed from wings and bodies can be manipulated by using flow control techniques. Flow physics of these approaches involve flow separation from the edge, roll-up into the vortex, wing flow regime, vortex instabilities, vortex-vortex interactions, and vortex-turbulence interactions. Actuators include continuous and unsteady blowing and suction, bleed, and control surfaces, which add momentum, vorticity and turbulence into the vortices. It is noted that actuation may have effects on more than one aspect of the flow phenomena. A comparative review of the control of delta wing vortices, tip vortices, and afterbody vortices is presented. The delay of vortex breakdown and the promotion of flow reattachment require different considerations for slender and nonslender delta wings, and may not be possible at all. Tip vortices can be controlled to increase the effective span, to generate rolling moment, to attenuate wing-rock, and to attenuate vortex-wing interactions. While there are different approaches for each application, opportunities for future research on turbulence ingestion, bleed, and excitation of vortex instabilities exist. Recent research also indicates that active and passive flow control can be used to manipulate the afterbody vortices in order to reduce the drag.

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“…Therefore, fast-switching solenoid valves can perform more effectively in controlling the flow separation and the aerodynamic stall at high Reynolds numbers. In this regard, several experimental investigations used fast-switching solenoid valves to generate pulsed jets from the upper surface of multi-element airfoils, in order to understand the effectiveness of pulsed jet actuators on the flow separation control and its dependence on the major parameters, such as the pulsing frequency, duty cycle, momentum coefficient, actuator location, and actuator orientation [10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Parametric study of a frequency-modulated pulse jet by measurements of flow characteristics

2021

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Recently, pulsed jet actuators have been discovered as an efficient and promising technique for flow separation control. In this paper, a systematic experimental investigation is carried out using a flow control approach, in order to study the flow field characteristics of a baseline single pulsed jet actuator, under different excitation conditions. The findings are used to provide a better understanding of pulsed blowing actuator operation and the associated flow physics. In these experiments, two types of signal waveforms have been implemented to produce the pulsed excitation of jet; a simple squarewave excitation signal for the first case and a burst modulated excitation signal for the second case. All measurements were conducted using a single hot-wire system to an axial distance x/D30 along the centerline. The effects of electrical parameters on properties of a single pulsed jet, including the excitation frequency from 10 up to 220 Hz and the duty cycle from 15% up to 80% for the first case, and different combinations of the carrier frequency and the modulating frequency for the second case have been studied. These measurements revealed a significant dependence of mean centerline velocity and turbulence intensity to excitation signal, frequency, and duty cycle. The statistical flow properties, such as mean centerline velocity decay and turbulence intensity distribution of pulsed jets are quantified and compared together over a wide range of pulsing parameters. This investigation aids in designing and optimizing flow control actuators in aerodynamics and combustion chambers. NomenclatureRECEIVED

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Control of Flow Structure over a Nonslender Delta Wing Using Periodic Blowing

Cited by 14 publications

References 42 publications

Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing

Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing

Flow Control of Tip/Edge Vortices

Parametric study of a frequency-modulated pulse jet by measurements of flow characteristics

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