Vortex breakdown studies of a canard-configured X-31A-like fighter aircraft model

1993 ◽  
Vol 30 (3) ◽  
pp. 405-408 ◽  
Author(s):  
Sheshagiri K. Hebbar ◽  
Max F. Platzer ◽  
Hui Man Kwon
Keyword(s):  
Vortex Breakdown ◽  
Fighter Aircraft ◽  
Aircraft Model

Detached-Eddy Simulations and Reynolds-Averaged Navier-Stokes Simulations of Delta Wing Vortical Flowfields

2002 ◽  
Vol 124 (4) ◽  
pp. 924-932 ◽  
Author(s):  
Scott Morton ◽  
James Forsythe ◽  
Anthony Mitchell ◽  
David Hajek
Keyword(s):  
Vortex Breakdown ◽  
Delta Wing ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Fighter Aircraft ◽  
Eddy Simulation ◽  
Reynolds Averaged Navier Stokes ◽  
High Reynolds

An understanding of vortical structures and vortex breakdown is essential for the development of highly maneuverable vehicles and high angle of attack flight. This is primarily due to the physical limits these phenomena impose on aircraft and missiles at extreme flight conditions. Demands for more maneuverable air vehicles have pushed the limits of current CFD methods in the high Reynolds number regime. Simulation methods must be able to accurately describe the unsteady, vortical flowfields associated with fighter aircraft at Reynolds numbers more representative of full-scale vehicles. It is the goal of this paper to demonstrate the ability of detached-eddy Simulation (DES), a hybrid Reynolds-averaged Navier-Stokes (RANS)/large-eddy Simulation (LES) method, to accurately predict vortex breakdown at Reynolds numbers above 1×106. Detailed experiments performed at Onera are used to compare simulations utilizing both RANS and DES turbulence models.

scholarly journals Delayed Antiwindup Control Using a Decoupling Structure

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Huawei Zhu ◽  
Guozheng Qin ◽  
Yingxin Yan ◽  
Zhichao Jiang ◽  
Zhisheng Duan
Keyword(s):  
Control Problem ◽  
Linear Matrix Inequalities ◽  
Input Saturation ◽  
Linear Matrix ◽  
Matrix Inequalities ◽  
Fighter Aircraft ◽  
Aircraft Model

This paper investigates the antiwindup (AW) control problem for plants with input saturation. The AW compensator is not activated as soon as input saturation occurs as usual. A delayed decoupling structure is first proposed. Then, appropriate linear matrix inequalities (LMIs) are developed to determine a plant-order AW compensator. Effectiveness of the presented AW technique is illustrated by a fighter aircraft model.

Experimental investigation of vortex breakdown over a sideslipping canard-configured aircraft model

1994 ◽  
Vol 31 (4) ◽  
pp. 998-1001 ◽  
Author(s):  
Sheshagiri K. Hebbar ◽  
Max F. Platzer ◽  
Chang Ho Kim
Keyword(s):  
Experimental Investigation ◽  
Vortex Breakdown ◽  
Aircraft Model

scholarly journals THE INFLUENCE OF FEATURES OF VORTEX FLOW ON AERODYNAMIC CHARACTERISTICS OF THE SUPERSONIC MANEUVERABLE AIRCRAFT MODEL

2019 ◽  
Vol 22 (1) ◽  
pp. 63-75
Author(s):  
K. A. Osipov
Keyword(s):  
Vortex Flow ◽  
Vortex Breakdown ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Slip Angle ◽  
Plan View ◽  
Aircraft Model ◽  
Wide Range ◽  
Flow Features ◽  
Secondary Vortices

The paper presents the influence of the vortex flow features, in particular, the phenomenon of vortex burst on the longitudinal and lateral aerodynamic characteristics of the maneuverable aircraft model with a sharp-edged fore-body. Numerical simulation of vortex flow has been conducted at low subsonic speeds (M = 0.15) in a wide range of angles of attack α = 0 ÷ 35° at zero sideslip β = 0°, as well as at fixed values of angles of attack a = 10,25,30,35° in a wide range of slip angles β = 0 ÷ 20° using k - ω SST turbulence model with curvature correction due to the insensitivity of the standard model to such effects. A satisfactory agreement of the numerical results with the experimental data on both longitudinal and lateral aerodynamic characteristics in a wide range of angles of attack and sideslip is obtained. According to the results of the numerical simulations, all the main nonlinearities in the integral characteristics associated with the vortex breakdown phenomenon and the interference of vortex structures were explained. The physical features of the vortex flow around the maneuverable aircraft model with a sharp-edged nose and their influence on the longitudinal and lateral aerodynamic characteristics are revealed. The phenomenon of vortex breakdown significantly affects the aerodynamic characteristics of the model. And with the increase of the angle of attack the point of vortex breakdown moves up the stream. At non zero sideslip vortices are destroyed asymmetrically, which leads to a loss of transverse stability of the model. The interaction of the nose and wing vortices, as well as the relative position of the points of vortex breakdown in the range of angles of attack 18° < α < 28° at zero slip angle lead to nonlinearities in the dependence of the lift coefficients and the longitudinal moment of the angle of attack. At large angles of attack, the main vortices forming from the sharp-edged nose make a major contribution to the change in the aerodynamic coefficients, in contrast to the round nose, where the yawing stability is often determined by secondary vortices. The phenomenon of vortex breakdown significantly affects the contribution of the sharp-edged nose to the yawing stability. Moreover, its effect can be radically different at different angles of attack (a = 25-30° and 35°). The local change in the contours of the fore-body in the plan view also significantly affects the directional stability due to the delaying of the vortex burst.

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