scholarly journals Redesign of Morphing UAV for Simultaneous Improvement of Directional Stability and Maximum Lift/Drag Ratio

2018 ◽  
Vol 18 (4) ◽  
pp. 57-62 ◽  
Author(s):  
S. ARIK ◽  
I. TURKMEN ◽  
T. OKTAY
Keyword(s):  
Directional Stability ◽  
Drag Ratio ◽  
Morphing Uav

Neural network based redesign of morphing UAV for simultaneous improvement of roll stability and maximum lift/drag ratio

2018 ◽  
Vol 90 (8) ◽  
pp. 1203-1212 ◽  
Author(s):  
Tugrul Oktay ◽  
Seda Arik ◽  
Ilke Turkmen ◽  
Metin Uzun ◽  
Harun Celik
Keyword(s):  
Neural Network ◽  
Artificial Intelligence ◽  
Objective Function ◽  
Aircraft Design ◽  
Stability Coefficient ◽  
Content Type ◽  
Abc Algorithm ◽  
Artificial Intelligence Methods ◽  
Drag Ratio ◽  
Morphing Uav

Purpose The aim of this paper is to redesign of morphing unmanned aerial vehicle (UAV) using neural network for simultaneous improvement of roll stability coefficient and maximum lift/drag ratio. Design/methodology/approach Redesign of a morphing our UAV manufactured in Faculty of Aeronautics and Astronautics, Erciyes University is performed with using artificial intelligence techniques. For this purpose, an objective function based on artificial neural network (ANN) is obtained to get optimum values of roll stability coefficient (Clβ) and maximum lift/drag ratio (Emax). The aim here is to save time and obtain satisfactory errors in the optimization process in which the ANN trained with the selected data is used as the objective function. First, dihedral angle (φ) and taper ratio (λ) are selected as input parameters, C*lβ and Emax are selected as output parameters for ANN. Then, ANN is trained with selected input and output data sets. Training of the ANN is possible by adjusting ANN weights. Here, ANN weights are adjusted with artificial bee colony (ABC) algorithm. After adjusting process, the objective function based on ANN is optimized with ABC algorithm to get better Clβ and Emax, i.e. the ABC algorithm is used for two different purposes. Findings By using artificial intelligence methods for redesigning of morphing UAV, the objective function consisting of C*lβ and Emax is maximized. Research limitations/implications It takes quite a long time for Emax data to be obtained realistically by using the computational fluid dynamics approach. Practical implications Neural network incorporation with the optimization method idea is beneficial for improving Clβ and Emax. By using this approach, low cost, time saving and practicality in applications are achieved. Social implications This method based on artificial intelligence methods can be useful for better aircraft design and production. Originality/value It is creating a novel method in order to redesign of morphing UAV and improving UAV performance.

Performance and Stability Characteristics of an Electrodynamically Levitated Vehicle Over a Split Guideway

1976 ◽  
Vol 98 (3) ◽  
pp. 277-285 ◽  
Author(s):  
J. Y. Wong ◽  
J. P. Howell ◽  
R. G. Rhodes ◽  
B. E. Mulhall
Keyword(s):  
Magnet System ◽  
System Parameters ◽  
Directional Stability ◽  
Drag Ratio

The results of an investigation into the performance and stability characteristics of an electrodynamically levitated vehicle using an integrated magnet system over a flat split guideway are described. The effects of system parameters on the lift/drag ratio, guidance and directional stability are examined in detail.

Gurney flap scaling for optimum lift-to-drag ratio

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1888-1890 ◽  
Author(s):  
Philippe Giguere ◽  
Guy Dumas ◽  
Jean Lemay
Keyword(s):  
Gurney Flap ◽  
Drag Ratio ◽  
Lift To Drag Ratio

scholarly journals A Parametric Study of Trailing Edge Flap Implementation on Three Different Airfoils Through an Artificial Neuronal Network

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 828
Author(s):  
Igor Rodriguez-Eguia ◽  
Iñigo Errasti ◽  
Unai Fernandez-Gamiz ◽  
Jesús María Blanco ◽  
Ekaitz Zulueta ◽  
...  
Keyword(s):  
Aerodynamic Coefficients ◽  
Trailing Edge ◽  
High Lift ◽  
Trailing Edge Flaps ◽  
Artificial Neural Network Ann ◽  
Lift And Drag ◽  
Artificial Neuronal Network ◽  
Naca 0012 ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Trailing edge flaps (TEFs) are high-lift devices that generate changes in the lift and drag coefficients of an airfoil. A large number of 2D simulations are performed in this study, in order to measure these changes in aerodynamic coefficients and to analyze them for a given Reynolds number. Three different airfoils, namely NACA 0012, NACA 64(3)-618, and S810, are studied in relation to three combinations of the following parameters: angle of attack, flap angle (deflection), and flaplength. Results are in concordance with the aerodynamic results expected when studying a TEF on an airfoil, showing the effect exerted by the three parameters on both aerodynamic coefficients lift and drag. Depending on whether the airfoil flap is deployed on either the pressure zone or the suction zone, the lift-to-drag ratio, CL/CD, will increase or decrease, respectively. Besides, the use of a larger flap length will increase the higher values and decrease the lower values of the CL/CD ratio. In addition, an artificial neural network (ANN) based prediction model for aerodynamic forces was built through the results obtained from the research.

scholarly journals Some Key Issues in Hypersonic Propulsion

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3690
Author(s):  
Claudio Bruno ◽  
Antonella Ingenito
Keyword(s):  
Kinetic Energy ◽  
Constant Volume ◽  
Supersonic Combustion ◽  
Relative Importance ◽  
Friction Drag ◽  
Wave Versus ◽  
Hypersonic Propulsion ◽  
Key Issues ◽  
Drag Ratio ◽  
Critical Aspects

This paper summarizes and discusses some critical aspects of flying hypersonically. The first is the L/D (lift over drag) ratio determining thrust and that in turn depends on the slenderness Küchemann’s τ parameter. This second parameter is found to depend on the relative importance of wave versus friction drag. Ultimately, all engineering drag is argued to depend on vorticity formed at the expense of the vehicle kinetic energy, thus requiring work by thrust. Different mixing strategies are discussed and shown to depend also on mechanisms forming vorticity when the regime is compressible. Supersonic combustion is briefly analyzed and found, at sufficiently high combustor Mach, to take place locally at constant volume, unlike conventional Brayton cycles.

scholarly journals Unsteady Simulation of Transonic Buffet of a Supercritical Airfoil with Shock Control Bump

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 203
Author(s):  
Yufei Zhang ◽  
Pu Yang ◽  
Runze Li ◽  
Haixin Chen
Keyword(s):  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Flow Characteristics ◽  
Control Effect ◽  
Shock Control Bump ◽  
Shock Control ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Unsteady Simulation ◽  
Drag Ratio

The unsteady flow characteristics of a supercritical OAT15A airfoil with a shock control bump were numerically studied by a wall-modeled large eddy simulation. The numerical method was first validated by the buffet and nonbuffet cases of the baseline OAT15A airfoil. Both the pressure coefficient and velocity fluctuation coincided well with the experimental data. Then, four different shock control bumps were numerically tested. A bump of height h/c = 0.008 and location xB/c = 0.55 demonstrated a good buffet control effect. The lift-to-drag ratio of the buffet case was increased by 5.9%, and the root mean square of the lift coefficient fluctuation was decreased by 67.6%. Detailed time-averaged flow quantities and instantaneous flow fields were analyzed to demonstrate the flow phenomenon of the shock control bumps. The results demonstrate that an appropriate “λ” shockwave pattern caused by the bump is important for the flow control effect.

scholarly journals Effect of Torsional Properties of CFRP Golf Club Shafts on Speed and Directional Stability of Ball

1997 ◽  
Vol 7 (1) ◽  
pp. 29-36
Author(s):  
Akiyoshi Kojima ◽  
Hideyuki Horii ◽  
Michihiro Mohri ◽  
Hideyuki Ohno
Keyword(s):  
Golf Club ◽  
Directional Stability ◽  
Torsional Properties

scholarly journals An estimation method for the fuel burn and other performance characteristics of civil transport aircraft during cruise: part 2, determining the aircraft’s characteristic parameters

2020 ◽  
Vol 125 (1284) ◽  
pp. 296-340
Author(s):  
D.I.A. Poll ◽  
U. Schumann
Keyword(s):  
Estimation Method ◽  
Accurate Method ◽  
Characteristic Parameters ◽  
Transport Aircraft ◽  
The Public ◽  
Engine Thrust ◽  
Fuel Burn ◽  
Burn Rate ◽  
Drag Ratio ◽  
Independent Parameters

ABSTRACTA simple yet physically comprehensive and accurate method for the estimation of the cruise fuel burn rate of turbofan powered transport aircraft operating in a general atmosphere was developed in part 1. The method is built on previously published work showing that suitable normalisation reduces the governing relations to a set of near-universal curves. However, to apply the method to a specific aircraft, values must be assigned to six independent parameters and the more accurate these values are the more accurate the estimates will be. Unfortunately, some of these parameters rarely appear in the public domain. Consequently, a scheme for their estimation is developed herein using basic aerodynamic theory and data correlations. In addition, the basic method is extended to provide estimates for cruise lift-to-drag ratio, engine thrust and engine overall efficiency. This step requires the introduction of two more independent parameters, increasing the total number from six to eight. An error estimate and sensitivity analysis indicates that, in the aircraft’s normal operating range and using the present results, estimates of fuel burn rate are expected to be in error by no more than 5% in the majority of cases. Initial estimates of the characteristic parameters have been generated for 53 aircraft types and engine combinations and a table is provided.

scholarly journals An experimental investigation on static directional stability

2016 ◽  
Vol 29 (6) ◽  
pp. 1527-1540 ◽  
Author(s):  
Wen Jing ◽  
Wang Yankui ◽  
Deng Xueying
Keyword(s):  
Experimental Investigation ◽  
Directional Stability
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