Angle-of-Attack Sweep with Mesh Adaptation for High-Lift Configurations

2022 ◽  
Author(s):  
Aravind Balan ◽  
Michael A. Park ◽  
Stephen L. Wood ◽  
William K. Anderson ◽  
Kevin Jacobson
Keyword(s):  
Angle Of Attack ◽  
Mesh Adaptation ◽  
High Lift

scholarly journals Analisis karakteristik aerodinamika telescopic wing dengan konfigurasi sayap flying wing dan glider menggunakan metode pendekatan simulasi CFD

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Azhim Asyratul Azmi ◽  
Satriawan Dini Hariyanto ◽  
Arif Hidayat
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Aircraft Wing ◽  
High Lift ◽  
Tip Vortices ◽  
Wing Tip

A telescopic wing is a shape-changing method of the aircraft wing known as the morphing wing system. Wingspan extends capability on telescopic wing increasing the aspect ratio to get a high lift force. The telescopic wing on a flying wing configuration as an external wing and glider wing as an internal wing can be used to increase the coefficient lift (CL) when carrying out special missions. The aerodynamic characteristics using the Computational Fluid Dynamic (CFD) simulation approach is presented. For the 40% internal wingspan, the highest CL increment was 12.9% at a 10o angle of attack. For the 50% internal wingspan, the highest CL increment was 14.9% at a 10o angle of attack. on the 40% internal wing, the highest coefficient drag (CD) increment was 4.7%, and the largest CD increment on 50% internal was 9.5% at the angle of attack of 20o. The pressure distribution along the internal wingspan was uneven from an angle of attack of 15o due to the wing tip vortices of the external wing. Streamline pattern shown a bubble separation from the leading edge at an internal wing root by external wing tip vortices.Keywords: Morphing wing, telescopic wing, flying wing, glider

A Numerical Investigation of High Lift Coefficient Airfoils Near Regions of Stall

2013 ◽  
Author(s):  
Ravon Venters ◽  
Brian Helenbrook
Keyword(s):  
Experimental Data ◽  
Free Stream ◽  
Numerical Models ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Optimal Placement ◽  
Navier Stokes ◽  
Cross Sectional ◽  
High Lift ◽  
Optimal Angle

The cross-sectional geometry of a diffuser-augmented wind turbine (DAWT) is often that of a cambered airfoil oriented at an angle of attack such that the lift coefficient of the airfoil is maximal. Beyond this angle separation occurs, and the performance decreases. Thus, predicting this transition is important for creating an optimally designed diffuser. The focus of this work is to validate two numerical methods for predicting the onset of separation for highly cambered airfoils. The numerical models investigated are a Reynolds-averaged-Navier-Stokes (RANS) k–ε model and XFOIL. The results were compared to each other and to experimental data. Overall the most accurate model was the k–ε model. Using this model, an optimization of a 2D DAWT was performed which determined the optimal placement of the diffuser. This optimization showed that the optimal angle of attack for the diffuser is much greater than what one would expect based on the maximum lift angle of an airfoil in a free-stream.

Large thickness airfoils with high lift in the operating range of angle of attack

2014 ◽  
Vol 6 (3) ◽  
pp. 033110 ◽  
Author(s):  
Xingxing Li ◽  
Ke Yang ◽  
Lei Zhang ◽  
Jingyan Bai ◽  
Jianzhong Xu
Keyword(s):  
Angle Of Attack ◽  
High Lift ◽  
Operating Range ◽  
Large Thickness

scholarly journals High-Lift Optimization Design Using Neural Networks on a Multi-Element Airfoil

1998 ◽  
Author(s):  
Roxana M. Greenman ◽  
Karlin R. Roth
Keyword(s):  
Neural Networks ◽  
Optimization Design ◽  
Initial Conditions ◽  
Angle Of Attack ◽  
Computational Time ◽  
Data Set ◽  
High Lift ◽  
Marquardt Algorithm ◽  
Gradient Based ◽  
The Neural Networks

Abstract The high-lift performance of a multi-element airfoil was optimized by using neural-net predictions that were trained using a computational data set. The numerical data was generated using a two-dimensional, incompressible, Navier-Stokes algorithm with the Spalart-Allmaras turbulence model. Because it is difficult to predict maximum lift for high-lift systems, an empirically-based maximum lift criteria was used in this study to determine both the maximum lift and the angle of attack at which it occurs. Multiple input, single output networks were trained using the NASA Ames variation of the Levenberg-Marquardt algorithm for each of the aerodynamic coefficients (lift, drag, and moment). The artificial neural networks were integrated with a gradient-based optimizer. Using independent numerical simulations and experimental data for this high-lift configuration, it was shown that this design process successfully optimized flap deflection, gap, overlap, and angle of attack to maximize lift. Once the neural networks were trained and integrated with the optimizer, minimal additional computer resources were required to perform optimization runs with different initial conditions and parameters. Applying the neural networks within the high-lift rigging optimization process reduced the amount of computational time and resources by 83% compared with traditional gradient-based optimization procedures for multiple optimization runs.

Some progress on CFD high lift prediction using metric-based anisotropic mesh adaptation

2022 ◽  
Author(s):  
Frederic Alauzet ◽  
Francesco Clerici ◽  
Adrien Loseille ◽  
Cosimo Tarsia-Morisco ◽  
Julien Vanharen
Keyword(s):  
Mesh Adaptation ◽  
High Lift ◽  
Anisotropic Mesh ◽  
Anisotropic Mesh Adaptation

Design and Drag Analysis of Fixed Wing Unmanned Aerial Vehicle for High Lift

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Vikas Deulgaonkar ◽  
Malhar Patil ◽  
Vaidehi Patwardhan
Keyword(s):  
Theoretical Analysis ◽  
Unmanned Aerial Vehicle ◽  
Angle Of Attack ◽  
Close Correlation ◽  
Validation Process ◽  
High Lift ◽  
Aerial Vehicle ◽  
Simulation Results ◽  
Drag Analysis ◽  
Surveillance Applications

Present work deals with design and analysis of fixed wing aircraft model. Dimensions of aircraft are evaluated considering different factors as weight to be lifted, velocity of aircraft and cruising altitude. Using AIAA rulebook the dimensions of aircraft are fixed. Further the theoretical analysis has been carried out using classical equations for evaluating drag co-efficient with respect to angle of attack and lift co-efficient. The airfoil selection has been carried out by comparing the characteristics of co-efficient of lift, drag and their behaviour against angle of attack for a range of 1 to 10. Using the theoretical outcomes the behaviour of entire aircraft was observed. Simulation of the aircraft has been carried out using XFLR5 software. The theoretical and simulation outcomes are observed to follow similar pattern for co-efficient of drag against both angle of attack and lift co-efficient. Close correlation has been observed between theoretical and simulation results. Present paper presents a design and analysis validation process for aircrafts used in surveillance applications.

Study on Wing Aspect Ratio on the Performance of a Gliding Robotic Fish

2015 ◽  
Vol 786 ◽  
pp. 248-253 ◽  
Author(s):  
Javaid Muhammad Yasar ◽  
Ovinis Mark ◽  
T. Nagarajan ◽  
Syed Saad Azhar Ali ◽  
Ullah Barkat
Keyword(s):  
Aspect Ratio ◽  
Angle Of Attack ◽  
Robotic Fish ◽  
Michigan State University ◽  
State University ◽  
High Lift ◽  
Aspect Ratios ◽  
Drag And Lift ◽  
Lift And Drag ◽  
Wing Aspect Ratio

In this paper, the performance of a gliding robotic fish with different wing aspect ratio is investigated. The gliding robotic fish, developed by Michigan State University, has the energy efficient locomotion of an underwater glider and high maneuverability of a robotic fish. ANSYS Computational Fluid Dynamics turbulence model was used to determine lift and drag coefficients for various wing aspect ratios at different angle of attack. Subsequently, the corresponding glide angle and velocity were determined analytically based on its dynamic model. The simulation results compare well with published experimental data and shows that the drag and lift coefficients are inversely proportional to the wing aspect ratio. As such, a gliding robotic fish with a low wing aspect ratio is suitable for shallow waters only, due to the high lift forces generated for a given angle of attack, requiring greater energy to sustain the glide velocity and vice versa.

High-Lift Mechanism of a Bionic Slat

2013 ◽  
Vol 461 ◽  
pp. 220-229
Author(s):  
Chang Jiang Ge ◽  
Mei Chen Ge
Keyword(s):  
Flow Field ◽  
Pressure Gradient ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Adverse Pressure Gradient ◽  
Element Model ◽  
Broadband Noise ◽  
High Lift ◽  
Edge Separation

To avoid broadband noise from a slat cove, the deployed slat contour is usually modified by filling cove, but the design is sensitive to aerodynamic performance. In the paper, a bionic slat without a cove is built on the basis of a bionic airfoil (i.e. stowed bionic multi-element airfoil), which is extracted from a long-eared owl wing. The quasi-two-dimensional models with a deployed bionic slat and a stowed bionic slat are manufactured by rapid manufacturing and prototyping system, respectively, and measured in a low-turbulence wind tunnel. The results are used to characterize high-lift effect: the lift coefficients of the model with a stowed slat are larger at less than 4°angle of attack, but the model with a deployed slat has the larger lift coefficients at greater than 4°angle of attack. Furthermore, the deployed bionic slat can increase stall angle and maximum lift coefficient, but also delay the decline of the lift coefficient curve slope meaning that the leading-edge separation is postponed within a certain range of angle of attack. At the same time, the flow field around the models is visualized by smoke wire method. The leading-edge separation of the model with a stowed slat is shown at low Reynolds number and angle of attack. However, the finding does not occur in the flow field of the model with a deployed slat at the same conditions, probably because the gap between the bionic slat and the main wing results in favorable pressure gradient, the deployed bionic slat decreases the peak of adverse pressure gradient by increasing the chord of the bionic multi-element model, and the bionic slat wake excites transition to the boundary layer on upper surface of the main wing. This superiority may be used as reference in the design of the leading-edge slat without a cove.

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