Leading-Edge Radius Effects on Aerodynamic Characteristics of 50-Degree Delta Wings

Verhaagen, N.G.

doi:10.2514/1.c031550

Cited by 19 publications

(12 citation statements)

References 20 publications

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“…Over the past few decades, most research was done on the vortices over slender sharp-edged delta wings. 13 Some early works in this field were reviewed by Sun 14 and most recently by Mitchell et al 4 In one of the earliest studies, for example, Jensen (1948) 15 studied the low-speed flowfields and the lift and moment characteristics of a sweptback wing and a delta wing, both with a 65 • sweptback leading edge and a double wedge symmetrical airfoil section. His results showed that two strong vortices are formed over the upper surfaces of both wings for angles of attack as low as 10 • .…”

Section: Vortical Flowsmentioning

confidence: 99%

Vortical Flow Prediction of the AVT-183 Diamond Wing

Ghoreyshi

Ryszka

Cummings

et al. 2015

53rd AIAA Aerospace Sciences Meeting

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The objective of this paper is to assess the potential and limitations of current practice in computational fluid dynamic modeling for predicting vortical flowfields over a generic 53-degree swept diamond wing with rounded leading edges. This wing was designed under STO AVT Task Group 183 and is based on the SACCON UCAV geometry, which is a lambda wing with complex span-wise distributions of thickness and leading edge radius and with a linear twist outboard of the first trailing edge break. The SACCON wing trailing-edge was swept forward by 26.5-degrees to form a diamond-shaped planform that is used in this study. This new wing also has a constant NACA 64A-006 airfoil section with a leading edge radius of 0.264 percent chord and has no twist. CFD simulations were performed for various angles of attack at a Mach number of 0.15 and a Reynolds number of 2.7× 10 6 based on the mean aerodynamic chord to match experiments. CFD simulations were run with different turbulence models and with a limited assessment of Delayed Detached Eddy Simulation. The wind tunnel experiments of the diamond wing were carried out in the and include aerodynamic lift, drag, and pitch moment measurements as well as span-wise pressure distributions at different chord-wise locations. This data set is used to validate the CFD results. The results presented demonstrate that the CFD compare well with the experiments at small angles of attack; the pitch moment predicted by the SARC turbulence model provide a better match to experimental results than the SA model at moderate angles of attack; and at high angles of attack, CFD predictions are not as good. The flow visualization results show that a leading-edge vortex is formed above the upper surface of the wing at an angle of attack of about eight degrees. This vortex becomes larger and stronger when the angle of attack is increased. With increasing angle of attack, the vortex formation point moves upstream and the vortex core moves inboard towards the wing center. Finally, the results show that the flow over the diamond wing is steady throughout the range of angles of attack.

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Section: Vortical Flowsmentioning

confidence: 99%

Vortical Flow Prediction of the AVT-183 Diamond Wing

Ghoreyshi

Ryszka

Cummings

et al. 2015

53rd AIAA Aerospace Sciences Meeting

View full text Add to dashboard Cite

show abstract

“…The time-averaged data show a smooth distribution of the vorticity in the free shear layer and no clear separate vortical substructures.. Plots of the instantaneous axial vorticity were presented in a previous paper 18 . The plots did show the existence of separate vortical substructures in the free shear layer, indicating that this layer breaks up rapidly into a highly turbulent wake-type flow.…”

Section: Flow Datamentioning

confidence: 99%

“…The overall effect on the C L -to-C D ratio is that up to α = 6 o wing I has the largest ratio, while beyond this angle wing III dominates with the largest ratio at α = 10 o . 18 An effect of r le can also be noted on the pitching-moment coefficient C m ; the level of this coefficient increases with α and decreases with increasing r le . Related to the strong decline in C L , a strong decline in C m can be observed again at α beyond 20 o .…”

Section: B Balance Datamentioning

confidence: 99%

“…18. The data were acquired at α from 5 o to 25 o , in steps of 5 o , and at Re ranging from 0.50 to 2.17 million.…”

Section: B Balance Datamentioning

confidence: 99%

“…These preliminary tests were performed in a small open wind tunnel and the results have been reported in a previous paper. 18 The oil-flow visualization study showed a clear effect of r le on the location of the secondary-separation line; a larger radius delays the outward bending of the secondary-separation line, which is indicative for a delay in the occurrence of vortex bursting over the models. The PIV data showed that a larger r le reduces the size and strength of the primary vortex and moves this vortex outboard and closer to the wing surface.…”

Section: Introductionmentioning

confidence: 99%

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Flow over 50o Delta Wings with Different Leading-Edge Radii

Verhaagen

2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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The experimental study focuses on the effects of the leading-edge radius on the flow over 50 o swept delta wing models. Three models were tested, one model has a sharp leading edge and two other have a semi-circular leading edge of different radius. The vortical flow on and off the surface of the models was investigated using an oil-flow visualization and a Stereo Particle Image Velocimetry (SPIV) technique. The leading-edge radius is shown to affect the location, size and strength of the vortices and also the vortex core breakdown location over the models. As a result of this, the forces and moment acting on a 50 o delta wing are also affected. The study further shows that the structure of the flow over such a wing is weakly dependent on Reynolds number.

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Inverse design optimization framework via a two-step deep learning approach: application to a wind turbine airfoil

Yang

Lee

Yee

2022

Engineering with Computers

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The inverse approach is computationally efficient in aerodynamic design as the desired target performance distribution is prespecified. However, it has some significant limitations that prevent it from achieving full efficiency. First, the iterative procedure should be repeated whenever the specified target distribution changes. Target distribution optimization can be performed to clarify the ambiguity in specifying this distribution, but several additional problems arise in this process such as loss of the representation capacity due to parameterization of the distribution, excessive constraints for a realistic distribution, inaccuracy of quantities of interest due to theoretical/empirical predictions, and the impossibility of explicitly imposing geometric constraints. To deal with these issues, a novel inverse design optimization framework with a two-step deep learning approach is proposed. A variational autoencoder and multi-layer perceptron are used to generate a realistic target distribution and predict the quantities of interest and shape parameters from the generated distribution, respectively. Then, target distribution optimization is performed as the inverse design optimization. The proposed framework applies active learning and transfer learning techniques to improve accuracy and efficiency. Finally, the framework is validated through aerodynamic shape optimizations of the wind turbine airfoil. Their results show that this framework is accurate, efficient, and flexible to be applied to other inverse design engineering applications.

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Leading-Edge Radius Effects on Aerodynamic Characteristics of 50-Degree Delta Wings

Cited by 19 publications

References 20 publications

Vortical Flow Prediction of the AVT-183 Diamond Wing

Vortical Flow Prediction of the AVT-183 Diamond Wing

Flow over 50o Delta Wings with Different Leading-Edge Radii

Inverse design optimization framework via a two-step deep learning approach: application to a wind turbine airfoil

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