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Canard-wing interactions in subsonic flow
, Article Iranian Journal of Science and Technology - Transactions of Mechanical Engineering ; Volume 37, Issue M2 , 2013 , Pages 133-147 ; 22286187 (ISSN) ; Davari, A. R ; Soltani, M. R ; Sharif University of Technology
Shiraz University
2013
Abstract
Extensive subsonic wind tunnel tests were conducted on a coplanar wing-canard configuration at various angles of attack. In these experiments, a 60° swept canard was placed upstream of a 60° swept main delta wing. This paper deals with the distribution of mean and fluctuating pressure coefficients on the upper surfaces of both the canard and the wing immersed in a variety of angles of attack. According to the results, presence of canard postpones the vortex formation and growth on the wing to higher angles of attack compared to the canard-off case. Due to the canard downwash field, the wing operates at lower effective angles of attack and therefore, its vortex breakdown is delayed. The...
Canard flow improvement in a split canard configuration
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 229, Issue 6 , 2015 , Pages 1076-1087 ; 09544100 (ISSN) ; Askari, F ; Soltani, M. R ; Sharif University of Technology
Abstract
Extensive low-speed wind-tunnel tests are performed to study the flow field structure over a dual-surface canard, known as split canard, in comparison to the conventional configurations. Surface pressure for both steady deflections and unsteady oscillations of the canard are measured and compared for both canard-alone and split-canard cases. The split canard shows a superior advantage at high angles of attack, where a delay in the vortex breakdown phenomena on the canard surface is observed. For the split-canard configuration, the downwash of the front canard reduces the effective angle of attack at the inboard section of the rear element which postpones formation of the leading-edge vortex....
Experimental Investigation of the Effects of Canard Position on the Flowfield Over the Wing of a Model
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
The analysis results of air combat simulations explain fighters succeed at close air combat that are super maneuverable and at high angle of attack controllable. Closed-coupled delta wing/canard configurations play an important role in modern aircraft design. These configurations offer high trimmed lift, improved agility and maneuverability as well, as a potential for increased lift-to drag ratio, all of which make them attractive to study. Experiments were carried out in a subsonic closed circuit wind tunnel over a delta wing model under the influence of canard. Canard was set in two different vertical positions, high and mid, with respect to the wing location. Flowfield measurements were...
Experimental Investigation of the Effects of Wing Aspect ratio and its distance from the Tail on the Aerodynamic parameters at high A.O.A
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor) ; Hejranfar, Kazem (Supervisor)
Abstract
In recent years, requirement to increase projectile performance, leads to a great interest in high angle of attack Aerodynamics. Projectile Maneuverability is a concept which is defined by having the capability to perform at high angles of attack while maintaining attached flow over the tail, rather than a capability of performing a mission in minimum possible duration. Interaction between body, wing and tail vortices can delay vortex breakdown over the wing and as a result may enhance projectile maneuverability. Studies show that wing aspect ratio and tail location have a remarkable influence on the vortices interaction and thus projectile maneuverability. In the present study, a series of...
Influence of Tail on the Wing Pressure Distribution of a Model at Different Conditions
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor) ; Ghorbanian, Kaveh (Supervisor)
Abstract
Control surfaces are used in combat aircrafts to control the pitching moment and to help the aircraft perform high angle of attack manoeuvres. For delta wing configuration, the flow characteristics around the horizontal tail depend on the wing and tail flow field and their interactions. The flow over delta wing is mainly characterised by strong vortices. These vortices move downstream and affect the tail flow field making the problem more complicated. The goal of this research is to study the effect of tail up wash on the horizontal wing-body- tail configurations in subsonic flow. For this purpose a series of wind tunnel tests were conducted on a model containing a moveable horizontal tail...
Effects of canard position on wing surface pressure
, Article Scientia Iranica ; Volume 17, Issue 2 B , 2010 , Pages 136-145 ; 10263098 (ISSN) ; Askari, F ; Davari, A. R ; Nayebzadeh, A ; Sharif University of Technology
2010
Abstract
A series of wind tunnel tests were performed to study the effects of a canard and its position on the downstream flowfield over the wing surface. The wing surface pressure was measured for both canard-off and canard-on configurations. In addition, the canard position effects on the wing were investigated at different angles of attack. The canard was installed at three vertical positions and at two different horizontal distances from the wing apex. The results show a remarkable increase in the wing suction peak for the canard-on configurations. At low to moderate angles of attack, among the various configurations examined in the present experiments, the mid-canard configuration developed a...
Effect of Delta Wing Leading Edge Vortex on Pressure Distribution of Fuselagein in Subsonic Regime
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor) ; Ghorbanian, Kaveh (Supervisor)
Abstract
The delta wing has proven to be very useful for the study and understanding of the basic features of separation-induced vortex flows since many aspects of these vortex flows can be generated with this simple shape. A phenomenon of special importance to vortical flows is vortex breakdown. Vortex breakdown remains an important and complicated phenomenon that can have negative or positive effects. The delta wing leading edge vortex is emphases in many experiments. Most of these experiments are focused on the delta wing only.In this research, emphasis is on vortex interaction of delta wing-canard-fuselage configuration. A series of low speed wind tunnel tests were carried out to investigate...
Experimental Investigation of Flow Past a Delta Wing Model in Presence of a Canard in Supersonic Regime
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
Application of canard next to the wing have been widely used in military industry for decades. Although it’s most application is in supersonic flying objects, It has to do it’s duty in lower air speeds too. The aim of this study was to investigate the influence on the wing due to the presence of canard in supersonic flow regime. But because of the importance of the issue, significant attempts has been conducted in subsonic flow regime. High research volume, Absence of a comprehensive theory in this branch and the local defense industry demand as a developing country on the other hand, delivers the importance and applicability of the subject. Another issue of importance is that the...
Investigation of the Leading Edge Flap Effects on the Aerodynamic Coefficients of a Cranked Arrow Delta Wing
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
In this study, investigated the simulation flow over a double-delta wing. The flow field was simulated by three dimension grid and RANS flow equation by K-ω-SST model. In order to investigate effect of AOA and leading edge flap simulated variable AOA and leading edge flap angle. The results shows created two vortex in inside and outside the wing. The vortex burst at high AOA and the Lift decrease after vortex bursting. The using leading edge flap effect on the vortex power and postpone vortex bursting and increasing wing lift coefficient in the high AOA. Also the leading edge flap effect on the pitch moment coefficient and change the pitch moment coefficient curve slope. The other effects of...
Experimental investigation of Pressure Distribution over Delta Wing in
Sub/supersonic Speed
,
M.Sc. Thesis
Sharif University of Technology
;
Soltani, Mohammad Reza
(Supervisor)
Abstract
Flow characteristics analysis over a wing, is one of the pioneer challenges in super and sub-sonic flow near flying objects. Taking into account of growing rate of low aspect ratio utilization, usually called Delta wings, investigation of vortex behavior over this wings is highly noticeable. In addition, the lack of research in this branch of Aerodynamics inside the country, considering it’s critical application, has doubled the importance of doing research in this filled. Experimental researches on super-sonic flow over a Delta wing is limited and there are not much accurate researches about vortexes in this category of wings. In this work, the main effort is to investigate the phenomena in...
Aeroelastic Analysis of Flying Wing Aircrafts
, M.Sc. Thesis Sharif University of Technology ; Dehghan Firouzabadi, Rouhollah (Supervisor) ; Haddadpour, Hassan (Supervisor)
Abstract
Purpose of this thesis is to discover the governing equation of Flying Wing aircrafts. In Flying Wing aircrafts crew, payload, fuel, and equipment are typically housed inside the main wing structure. A clean flying wing is sometimes presented as theoretically the most aerodynamically efficient (lowest drag) design configuration for a fixed wing aircraft. We assume Flying wing as plate. Achieve structural formulation needs to use modal deflections and put them in Lagrangian equations. In the right had side, pressure on flying wing can be found. To obtain air pressure on flying wing in this thesis, applying Quasi steady aerodynamic and Howe distribution is necessary. Applying this method on ...
An Experimental Investigation of Unsteady Flow Over a Delta Wing in Supersonic Regime
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
Focusing on unsteady flow field over delta wings due to vacuity of researches in this branch on one hand and requiring of modern aircrafts designers to this science on the other hand, expresses necessity of accomplishing present investigation. Scrutiny of pressure distribution of low aspect ratio wings in unsteady state and determination of aerodynamic characteristics of these wings in variant conditions, can be beneficial to plan aircrafts need to fly with high maneuverability in high speeds. This issue becomes important when in supersonic regime, with respect to emerged shock waves and vortices, develop complicated pressure distributions on the wing surface in unsteady state that affect...