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Supersonic flow over a pitching delta wing using surface pressure measurements and numerical simulations

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Chinese Journal of Aeronautics 2018年第1期31卷 65-78页

作者： Mostafa HADIDOOLABI Hossein ANSARIAN Aerospace Engineering Department Malek Ashtar University of Technology

Experimental and numerical methods were applied to investigating high subsonic and supersonic flows over a 60°swept delta wing in fixed state and pitching oscillation. Static pressure coefficient distributions over the wing leeward surface and the hysteresis loops of pressure coefficient versus angle of attack at the sensor locations were obtained by wind tunnel tests. Similar results were obtained by numerical simulations which agreed well with the experiments. Flow structure around the wing was also demonstrated by the numerical simulation. Effects of Mach number and angle of attack on pressure distribution curves in static tests were investigated. Effects of various oscillation parameters including Mach number, mean angle of attack, pitching amplitude and frequency on hysteresis loops were investigated in dynamic tests and the associated physical mechanisms were discussed. Vortex breakdown phenomenon over the wing was identified at high angles of attack using the pressure coefficient curves and hysteresis loops, and its effects on the flow features were discussed.

关键词： delta wing Hysteresis loop Pitching oscillation Supersonic flow Vortex breakdown

Effects of sinusoidal leading edge on delta wing performance and mechanism

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Science China Technological Sciences 2013年第3期56卷 772-779页

作者： CHEN Huang PAN Chong WANG JinJun Fluid Mechanics Key Laboratory of Ministry of Education Beihang University

Lift and drag characteristics of delta wings with low swept angle and various sinusoidal leading edges(SLE) were investigated in a wind *** amplitudes and three wavelengths of SLE were *** is revealed that,in comparison with the baseline case,when the leading-edge amplitude A?5%C(root chord length of a delta wing),the stall of the delta wing can be delayed without penalty on the maximum lift coefficient;meanwhile,the lift-to-drag ratio was kept nearly *** are beneficial to aircraft maneuverability and *** oil and hydrogen-bubble flow visualization experiments were further conducted to provide a general view of the underlying flow mechanism of SLE on delta *** was found that,for the flow over delta wing with SLE,vortices were generated from every crest of SLE,in contrast to the dual leading-edge vortex structure generated from the apex of the base *** high angle of attack,the breakdown of those vortices originating from the crests of SLE may provide additional turbulent kinetic energy to the flow,resulting in the increase of the flow reattachment region on the leeward side,therefore the stall can be delayed.

关键词： delta wing sinusoidal leading edge aerodynamic performance leading-edge vortex

Supersonic flow of a Chaplygin gas past a delta wing

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Science China Mathematics 2022年第11期65卷 2271-2296页

作者： Bingsong Long Chao Yi School of Mathematics and Statistics Huanggang Normal UniversityHuanggang 438000China Center for Mathematical Sciences Huazhong University of Science and TechnologyWuhan 430074China

We consider the problem of supersonic flow of a Chaplygin gas past a delta wing with a shock or a rarefaction wave attached to the leading *** flow under study is described by the three-dimensional steady Euler *** conical coordinates,this problem can be reformulated as a boundary value problem for a nonlinear equation of mixed *** type of this equation depends fully on the solutions of the problem itself,and thus it cannot be determined in *** overcome the difficulty by establishing a crucial Lipschitz estimate,and finally prove the unique existence of the solution via the method of continuity.

关键词： supersonic flow delta wing Chaplygin gas boundary value problem equation of mixed type

A Study of the Vortical Flow over a delta wing with a Leading Edge Extension

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Journal of Thermal Science 2003年第4期12卷 299-303页

作者： Heuy-Dong Kim Young-Ki Lee Tae-Ho Kim Myoung-Hwan Sohn School of Mechanical Engineering Andong National University Andong 760-749 KoreaSchool of Mechanical Engineering Andong National University Andong 760-749 KoreaSchool of Mechanical Engineering Andong National University Andong 760-749 KoreaDepartment of Aerospace Engineering Korean Air Force Academy Chongwon-gun ChungBook-Do 363-849 Korea

The present paper describes computational and experimental work on the vortex flow characteristics of a sharp-edged delta wing with a leading edge extension (LEX). Experiment was carried out using a low-speed wind tunnel that has a test section of 3.5 m(W)×2.45 m(H)×8.7 m(L). The angle of attack of the delta wing ranges from 10° to 30°. The free stream velocity is fixed at 20 m/s, which corresponds to Reynolds number of 0.88×106. Computations using the mass-averaged implicit 3D Navier-Stokes equations were applied to predict the complicated vortical flow over the delta wing. The governing equations were discretized in space using a fully implicit finite volume differencing formation. The standard k-e turbulent model was employed to close the governing equations. The present computations predicted the experimented flow field with a good accuracy.

关键词： delta wing leading edge extension (LEX) vortex core vortex strength.

Study on Forms of Vortex Breakdown over delta wing

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Chinese Journal of Aeronautics 2004年第1期17卷 13-16页

作者：吕志咏祝立国 The Inst. of fluid Mech. Beijing University of Aeronautics and Astronautics

Visualization test is performed at the water channel of BUAA. The vortex coreis visualized by dye injection from a small tube located upstream the apex of a delta wing. Thetest results are recorded by a video camera connected to a computer and processed by Photoshop^(^R)software. The test shows new findings in the following respects: (1) Besides the well known spiraland bubble forms of vortex breakdown, there are 3 other forms of vortex breakdown over delta wingfound in the test. They are the frog-jump form, the double spiral form and the filiform spiral form.(2) It has also been found that there is a transition from the spiral form to the bubble form andthen back to the spiral form in the test. Therefore it shows that the spiral form vortex breakdownover delta wing is often observed. (3) In a certain sense it can be said that the bubble form ofvortex breakdown is a special case of the spiral form type. There is no essential difference betweenthem. For the bubble form of vortex breakdown , there are branches of the vortex core and manyelements carrying vorticity separated from the vortex core. However, there is at least one vortexfilament that forms a spiral or a complex warping shape.

关键词： vortex breakdown delta wing unsteady

Aerodynamic improvement of a delta wing in combination with leading edge flaps

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Theoretical & Applied Mechanics Letters 2017年第6期7卷 357-361页

作者： Tadateru Ishide Mao Itazawa National Institute of Technology Kisarazu College2-1 1-1 Kiyomidai-higashiKisarazu CityChiba292-O041Japan

Recently, various studies of micro air vehicle （MAV） and unmanned air vehicle （UAV） have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold＇s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap （LEF） is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component toad ceil and particle image velocimetry （PIV） analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.

关键词： delta wing Leading edge flap PIV analysis Leading edge vortex Aerodynamic characteristics

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1113 delta wing

汽车知识 2015年第6期 48-49页

Q:deltawingj是一个怎么样的设计公司,它设计了哪些车型?A:您好,2010年,日产与英国设计师Ben Bowlby、赛事企业家Don Panoz、前美国F1赛车手Dan Gurney与Duncan Dayton所组成的团队,便开始合作进行新世代赛车的deltawing Racing开发计划... 详细信息

Q:deltawingj是一个怎么样的设计公司,它设计了哪些车型?A:您好,2010年,日产与英国设计师Ben Bowlby、赛事企业家Don Panoz、前美国F1赛车手Dan Gurney与Duncan Dayton所组成的团队,便开始合作进行新世代赛车的deltawing Racing开发计划,并在2012年3月间发表了delta wing这款令世人大开眼界的赛车,并以此车参加了勒芒二十四小时耐力赛。尽管看似合作愉快,随后日产

关键词：二十四小时概念车 delta wing

Analysis of Shock and Vortex Breakdown Behavior in Unsteady Transonic Flow on A Slender delta wing

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Analysis of Shock and Vortex Breakdown Behavior in Unsteady ...

Experimental Study on Aerodynamic Noise Radiated from delta wing

2010亚太航空航天技术研讨会

作者： Li Xile~* Yang Yong Jiao Jin National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi’an 710072 China

＜正＞A transonic flow around delta wing with sharp leading edge is simulated by detached eddy simulation（DES） *** behavior of the complex shock waves in unsteady flow on the top surface of delta wing is analyzed at moderate and high angles of *** well as the movement of the location of vortex breakdown induced by the *** results indicate that three normal shock waves exist on the top surface of delta wing at both incidence *** angle of incidence ofα=18.5°,the rear/terminating shock propagates upstream to the sting tip from trailing edge periodically,the strength of shock becomes weaker as it moves ***,the rear/ terminating shock amalgamates with the normal shock wave at the sting *** location of vortex breakdown is close to the trailing edge. At angle of incidence ofα=23°,a second shock appears upstream of the sting tip,which moves analogically with the terminating shock for the case ofα=18.5°,it indicates that this shock is the rear/terminating shock having undergone an upstream shift with the increase of *** while,the location of vortex breakdown induced by second shock moves periodically.

关键词： delta wing DES shock wave vortex breakdown periodic movement

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Journal of Mechanics Engineering and Automation 2020年第6期10卷 161-169页

作者： H.Honda S.Ogawa K.Suzuki National Institute of Technology(KOSEN) Kure College2-2-11 AgaminamiKure CityHiroshima Prefecture 737-8506Japan Department of Mechanical Engineering National Institute of Technology(KOSEN)Kure College2-2-11 AgaminamiKure CityHiroshima Prefecture 737-8506Japan

Aerodynamic noise has been impairing the comfort of passengers in *** have shown that the aerodynamic noise is generated by the separation of the flow and the generation of the longitudinal vortex at the front pillar(A-pillar)and the door *** remove the effects of the door mirror and extract the longitudinal vortex from A-pillar,studies employ the delta wing *** research also employed the model and observed relations between the generated sound from the vortex at the A-pillar and the surface pressure fluctuation of the *** experiment was carried out in a wind tunnel of the Japan Aerospace Exploration Agency(JAXA)wind tunnel using the delta wing *** radiated sound was measured using a far-field microphone to characterize the sound,and microphone array to conduct sound source *** of surface pressure fluctuation was measured using electret condenser *** showed that the radiated sound has a characteristic of dipole sound,and broadband sound from 1 kHz is radiated from the apex of the *** indicate that sound generated from the apex of the delta wing was scattered at the surface of the delta wing,which follows the Lighthill-Curle *** pressure fluctuation with high fluctuation was distributed following the cone-like shape of the longitudinal *** peaks moved to the apex with the frequency *** between far-field sound and surface pressure fluctuation was *** point which is 70 mm inward from the apex showed higher value than those at the *** the diameter of the longitudinal vortex grows at the downstream,it is considered that a certain vortex scale radiates the most noise.

关键词： Aerodynamic noise longitudinal vortex delta wing experiment.