The concept of lateral blowing

Tavella, Domingo; Roberts, Leonard

doi:10.2514/6.1985-5000

Cited by 6 publications

(3 citation statements)

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“…Correspondingly larger lift augmentation and slope correspond to cases of larger lateral displacements of the primary vortex, in agreement with previous theoretical work. 9 This is confirmed by the lift distributions in Fig. 2 …”

Section: Discussionsupporting

confidence: 87%

“…Such outward displacement of the tip vortex can be related, through an algebraic scaling law, to jet momentum, wing aspect ratio, and angle of attack. 9 In the majority of the tests involving symmetrical slot configurations, the theoretically derived scaling laws were followed closely, except at very small angle of attack and intense blowing. In cases of nonsymmetrical slot configurations, deviPresented in part as Paper 86-1810 at the AIAA 4th Applied Aerodynamics Conference, San Diego, CA, June 9-11, 1986; received March 30, 1987; revision received March 7, 1988.…”

Section: Introductionmentioning

confidence: 94%

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Flow structure and scaling laws in lateral wing-tip blowing

et al. 1989

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When a thin jet sheet exits from the tip of a straight wing in the spanwise direction, the wing experiences a lift augmentation. In many cases, lateral blowing causes a lateral displacement of the tip vortices, without complicating the vortex structure. In such cases, simple scaling laws for blowing intensity and lift augmentation have been found to hold. However, in some instances blowing also produces secondary vortices, which sometimes are associated with a breakdown of the scaling laws. Flow surveys for several tip jet configurations giving rise to multiple-vortex structures were conducted in a low-speed wind tunnel. An analysis of the near wake structure in such cases indicated that the presence of strong secondary vortices provided the mechanism for the scaling-law breakdown. Nomenclature= freestream dynamic pressure u, v, w = u y v, w velocity components Wo, = free-stream velocity Vj = jet exit velocity x,y,z = streamwise, spanwise, and transverse coordinates a.-angle of attack dj = jet slot width r = vortex strength PJ = jet fluid density f = streamwise vorticity component

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Section: Discussionsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 94%

Flow structure and scaling laws in lateral wing-tip blowing

et al. 1989

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“…駆動が高速で入力に対する追随性が優れているなどの利点から，現在までに多くの応用例が報告されている．応用分野は多岐に渡り，壁面乱流摩擦抵抗や空力騒音の低減などに用いられている (9)(10) ほか，翼面剥離制御など翼周りの流れに関する様々な研究に多く用いられている (11)(13) ．翼周りの流れには剥離の問題以外に翼端渦と呼ばれる三次元性を持つ強力な縦渦の問題があり，その現象解明に向けて多くの実験的研究が行われてきた (14) (17) ．現在，航空需要の増加に伴い航空機の離着陸回数は増加傾向にあるが，翼端渦の発生は離着陸間隔制限の原因となっているため，その抑制は大きな課題となっている．また近年では燃費といった環境面の観点からも翼性能を維持しつつ翼端渦を抑制することが重要となっている (18) ．翼端渦の抑制手法としてはウイングレット (18)  (19) に代表されるパッシブな手法が既に実用化されているが，さ＊原稿受付 2010 年 8 月 18 日 *1 学生員，慶應義塾大学大学院理工学研究科(〒223-8522 神奈川県横浜市港北区日吉 3-14-1) *2 正員，Laboratoire de Mécanique de Lille(Bv Paul Langevin Cité Scientifique, 59655, Villeneuve d'Ascq Cédex) *3 正員，慶應義塾大学理工学部(〒223-8522 神奈川県横浜市港北区日吉 3-14-1) E-mail: hasebe@fukagata.mech.keio.ac.jp らに大きな効果を求めて，吹出し・吸込みを用いたアクティブな手法が研究されている (20) (22) ．図 1 にその模式図を示す．側面スロットからの吹出し・吸込みに関しては，定常的なものあるいは周期的に変化させるものが報告されている．中でも吹出しによる研究は多く行われ，吹出し方向により揚力増加の効果が大きく異なること，吹出し量や吹出し方向の違いにより翼端渦発生位置や渦直径に違いが現れることが実験的に示されている (21) ．吹出しに比べると吸込みを用いた研究例は尐ないが，吸込みを用いた研究では翼上面・後縁(吹き上げ速度最大点) 付近での翼端渦抑制効果が報告されている (22) ．スロットを用いた吹出し・吸込みデバイスの翼への実装は容易ではない．しかし，より簡単な構造のプラズマアクチュエータを用いた吹出し・吸込みでスロットと同様の効果が得られれば．アクティブ制御による翼端渦抑制技術の実用化への大きな一歩となる．また近年ではマイクロマシン(MEMS)技術を用いたマイクロ・プラズマアクチュエータも開発されており (23)…”

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An Attempt for Suppression of Wing-Tip Vortex Using Plasma Actuators

Hasebe¹,

Naka²,

Fukagata³

2011

Trans.JSME, Ser.B

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Influence of the flow induced by dielectric barrier discharge (DBD) plasma actuators on the wing-tip vortex is investigated numerically and experimentally. The plasma actuators are installed on the suction side of the NACA0012 airfoil and operated in blowing and suction modes. For the numerical simulation, direct numerical simulation (DNS) based on the finite-difference immersed-boundary method is used. The DNS shows that the circulation parameter, which measures the strength of wing-tip vortex, is reduced by blowing as well as suction. At the same time, however, the lift-to-drag ratio is found to decrease by the actuation. In the experiment, a wing model with plasma actuators is set inside the wind tunnel and the velocity components are measured using a PIV system. Although suppression of wing-tip vortex is not confirmed due to insufficient strength of actuation and insufficient length of messurement area, the change of streamwise mean velocity profile is found to be similar to that of DNS.

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An Attempt for Suppression of Wing-Tip Vortex Using Plasma Actuators

Hasebe

Naka

Fukagata

2011

JFST

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Influence of the flow induced by dielectric barrier discharge (DBD) plasma actuators on the wing-tip vortex is investigated numerically and experimentally. The plasma actuators are installed on the suction side of the NACA0012 airfoil and operated in blowing and suction modes. For the numerical simulation, direct numerical simulation (DNS) based on the finite-difference immersed-boundary method is used. The DNS shows that the circulation parameter, which measures the strength of wing-tip vortex, is reduced by blowing as well as suction. At the same time, however, the lift-to-drag ratio is found to decrease by the actuation. In the experiment, a wing model with plasma actuators is set inside the wind tunnel and the velocity fields are measured using a PIV system. Although suppression of wing-tip vortex is not confirmed due to insufficient strength of actuation and insufficient length of measurement area, the change of streamwise mean velocity profile is found to be similar to that of DNS.

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The concept of lateral blowing

Cited by 6 publications

References 0 publications

Flow structure and scaling laws in lateral wing-tip blowing

Flow structure and scaling laws in lateral wing-tip blowing

An Attempt for Suppression of Wing-Tip Vortex Using Plasma Actuators

An Attempt for Suppression of Wing-Tip Vortex Using Plasma Actuators

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