scholarly journals Computational Investigation of a Novel Box-Wing Aircraft Concept

2022 ◽  
Vol 12 (2) ◽  
pp. 752
Author(s):  
Mehedi Hasan ◽  
Stephane Redonnet ◽  
Andras Hernadi
Keyword(s):  
Structural Characteristics ◽  
Aerodynamic Performance ◽  
Research Model ◽  
Computational Investigation ◽  
Promising Alternative ◽  
Computational Fluid Dynamics Cfd ◽  
Novel Concept ◽  
Drag Ratio ◽  
Swept Wings ◽  
Lift To Drag Ratio

With regard to the current needs for greener aviation, this study focuses on a novel concept of Box-Wing Aircraft (BWA). Labelled SmartLiner (BWA/SL), this conceptual aircraft comes as a triplane comprising backward and forward swept wings. The aerodynamic performance and structural characteristics of this BWA/SL aircraft are here explored through numerical simulation, using Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI). The computational approach is first validated using NASA’s Common Research Model (CRM) aircraft, which is then taken as a reference solution against which to compare the aero-structural merits of the BWA/SL concept. Results show that, although its design is still preliminary and lacks optimization, the BWA/SL aircraft exhibits very decent aerodynamic performance, with higher lifting capacities and a reasonable lift-to-drag ratio. Moreover, thanks to the closed frame of its peculiar planform, it demonstrates superior structural characteristics, including under extreme loading scenarios. Based on this preliminary analysis and considering the room left for its further optimization, this conceptual aircraft thus appears as a potentially promising alternative for the development of more environmentally friendly airliners.

Modification impact on aerodynamic performance of hypersonic waverider

2011 ◽  
Vol 115 (1168) ◽  
pp. 325-334 ◽  
Author(s):  
C. Xiao-Qing ◽  
H. Zhong-Xi ◽  
L. Jian-Xia ◽  
G. Xian-Zhong
Keyword(s):  
Leading Edge ◽  
Aerodynamic Performance ◽  
Hypersonic Vehicles ◽  
Flow Conditions ◽  
Aerodynamic Coefficient ◽  
High Lift ◽  
Computational Fluid Dynamics Cfd ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Sharp Leading Edge

Abstract Waverider serves as a good candidate for hypersonic vehicles. The typical waverider has sharp leading edge and no control face, which is inappropriate for practical use. This paper puts forward a method modifying the waverider, and the modification impact on the performance of waverider at hypersonic flow conditions is studied. The modification is based on blunted waverider, includes cutting the tip and introducing two control wings. The modification’s effect on aerodynamic performance is obtained and analysed through Computational Fluid Dynamics (CFD) techniques. When blunted with 2cm radius, the waverider retains its good aerodynamic performance and the heat flux at the stagnation point can be managed. Three factors of the introduced wing are argued, the fixed angle, aspect ratio and wing area. Results show that influence on the aerodynamic coefficient is slight and the vehicle retains its high lift-to-drag ratio. The main influences of the modification are the control ability and trim efficiency, which is the motivation of this work and can be adapted when designing a practical waverider.

The aerodynamic optimisation of a low-Reynolds paper plane with adjoint method

2020 ◽  
pp. 1-15
Author(s):  
Y. Zhang ◽  
X. Zhang ◽  
G. Chen
Keyword(s):  
Adjoint Method ◽  
Low Cost ◽  
Aerodynamic Performance ◽  
Discrete Adjoint ◽  
Design Variables ◽  
Limited Variation ◽  
Aerial Vehicle ◽  
Paper Plane ◽  
Drag Ratio ◽  
Lift To Drag Ratio

ABSTRACT The aerodynamic performance of a deployable and low-cost unmanned aerial vehicle (UAV) is investigated and improved in present work. The parameters of configuration, such as airfoil and winglet, are determined via an optimising process based on a discrete adjoint method. The optimised target is locked on an increasing lift-to-drag ratio with a limited variation of pitching moments. The separation that will lead to a stall is delayed after optimisation. Up to 128 design variables are used by the optimised solver to give enough flexibility of the geometrical transformation. As much as 20% enhancement of lift-to-drag ratio is gained at the cruise angle-of-attack, that is, a significant improvement in the lift-to-drag ratio adhering to the preferred configuration is obtained with increasing lift and decreasing drag coefficients, essentially entailing an improved aerodynamic performance.

Dynamic Lift Coefficients for Spade Rudders on Yachts

2007 ◽  
Author(s):  
Paul H. Miller
Keyword(s):  
Lift Coefficient ◽  
Bending Moment ◽  
Pressure Profile ◽  
Element Analysis ◽  
Aspect Ratios ◽  
Back Calculation ◽  
Computational Fluid Dynamics Cfd ◽  
Sailing Yacht ◽  
Drag Ratio ◽  
Lift To Drag Ratio

The loss of a rudder is a dangerous situation for any vessel, and with the increasingly higher aspect ratios in current sailing yacht rudder designs, a better understanding of the forces on a rudder are required. While many failures have been caused by impacts with objects, a large number have failed due to underestimation of sailing loads. While larger aspect ratios increase the lift-to-drag ratio, they also increase the bending moment about the rudder’s root. Combined with thinner airfoil sections to reduce drag, modern rudders are highly stressed. Traditional design methods normally assume that the maximum lift coefficient is constant for all aspect ratios. This project combined computational fluid dynamics (CFD), finite element analysis (FEA) and the tank testing of a 1/5-scale yacht to determine suitable design lift coefficients for spade rudders of cruising and racing yachts. Two rudders of different aspect ratios were tested at various speeds, heel angles and wave conditions in the tank at the Naval Surface Warfare Center – Carderock Division. The rudders were equipped with strain gauges to determine the strains at various positions along the stock and blade. The strain profile was compared against FEA results that used a CFD prediction of the pressure profile. Through back-calculation the lift coefficients in still water and waves were derived. The results indicated that these lift coefficients are not constant.

Numerical Study of Improving Aerodynamic Performance of the Cylinder Airfoil of Magnus Wind Turbine

2013 ◽  
Vol 650 ◽  
pp. 414-419
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
Jin Ming Wu ◽  
Jian Guang Li
Keyword(s):  
Fluid Dynamics ◽  
Drag Force ◽  
Numerical Study ◽  
Rotating Cylinder ◽  
Aerodynamic Performance ◽  
Orthogonal Test ◽  
Performance Change ◽  
Result Show ◽  
Drag Ratio ◽  
Lift To Drag Ratio

To solve the problem of low lift to drag ratio of Magnus cylinder airfoil, the Computational Fluid Dynamics software Fluent was used to study the principle of a drop of the drag force of cylinder when rotating. And the principle was used to further reduce the drag of rotating cylinder. A traditional airfoil head and a triangle tail was used to study the effect of the aerodynamic performance change of the combined airfoil. A conclusion was made that with a suitable profile of the tail would reduce the drag force of the combined airfoil thus increase the lift to drag ratio of the airfoil. At last an orthogonal test was made to determine the size of the tail airfoil. The result show that the optimized airfoil reduce the drag force to 50% of the original cylinder and improve the lift to drag ratio to 50%.

Research on Improved Method of Wind Turbine Airfoil S834 Based on Noise and Aerodynamic Performance

2015 ◽  
Vol 744-746 ◽  
pp. 253-258 ◽  
Author(s):  
Ya Qiong Chen ◽  
Yue Fa Fang
Keyword(s):  
Wind Turbine ◽  
Optimization Design ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Parametric Modeling ◽  
Multi Objective ◽  
Wind Turbine Airfoil ◽  
Drag Ratio ◽  
Operating Points ◽  
Lift To Drag Ratio

In this paper, aerodynamic performance and noise of the wind turbine airfoil are the optimization design goal and based on this, the optimization design method with multi-operating points and multi-objective of the airfoils is built. The Bezier curve is used in parametric modeling of the contour of the airfoil and the general equation for control points is deduced form the discrete points coordinates of the airfoil. The weigh distribution schemes for multi-objective and multi-operating points are integrated designed by treating the NREL S834 airfoil as the initial airfoils. The results show that the lift-to-drag ratio of the optimized airfoils has a improvement around the designed operating angle and the overall noise has a reduction compared with the initial airfoils, which means that the optimized airfoils get a better aerodynamic and acoustic performance.

scholarly journals RESEARCH OF WING DIHEDRAL ANGLE EFFECT ON AERODYNAMIC PERFORMANCE OF TANDEM-WING UNMANNED AERIAL VEHICLE

2013 ◽  
pp. 90-101
Author(s):  
І. С. Кривохатько
Keyword(s):  
Dihedral Angle ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Theoretical Explanation ◽  
Wing Span ◽  
Induced Drag ◽  
Rear Wing ◽  
Angle Effect ◽  
Drag Ratio ◽  
Lift To Drag Ratio

In the last decade folding tube launch UAV became common, for which aerodynamic scheme "tandem" is reasonable. By the time tandem-wing aerodynamic characteristics are researched much less than ones of traditional scheme. Particularly it concerns wing dihedral angle effect on lift-to-drag ratio about which no quantitative data were found.Forward or rear wing dihedral angle appearance result in circulation redistribution and changing of rear wing induced drag. Rear wing dihedral angle effect on longitudinal aerodynamic performance of tandem-wing UAV model was researched through wind tunnel experiment. Geometry variables were forward and rear wing spans, rear wing dihedral angle and longitudinal stagger. Lift, drag and longitudinal moment coefficients were defined.The possibility of lift-to-drag ratio increasing at cruise regime was proofed. Rear wing negative dihedral angle application is able to increase maximal lift-to-drag ratio by more than 1.0 or about 10 %.It was found that wing dihedral angle effectiveness depends from relation of forward and rear wing spans and from longitudinal stagger. Longitudinal stagger increasing results in dihedral angle effectiveness falling if forward wing span is higher than rear wing. For bigger rear wing span increasing of longitudinal stagger results in dihedral angle effectiveness gaining. The hypothesis was declared that proposes theoretical explanation of experimentally founded dependencies.Also dihedral angle appearance increases lift slope because of rear wing carrying capacity gain and has almost no influence on maximal lift coefficient.All dependencies founded for rear wing negative dihedral angle are correct for forward wing positive dihedral angle except the last one is increasing longitudinal and lateral stability.

CFD analysis of variable geometric angle winglets

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Hussain Kazim ◽  
Abdullah Hamid Malik ◽  
Hammad Ali ◽  
Muhammad Usman Raza ◽  
Awais Ahmad Khan ◽  
...  
Keyword(s):  
Aerodynamic Performance ◽  
Sweep Angle ◽  
Content Type ◽  
Wing Model ◽  
Induced Drag ◽  
Computational Fluid Dynamics Analysis ◽  
Attached Flow ◽  
Drag Ratio ◽  
Fuel Costs ◽  
Lift To Drag Ratio

Purpose Winglets play a major role in saving fuel costs because they reduce the lift-induced drag formed at the wingtips. The purpose of this paper is to obtain the best orientation of the winglet for the Office National d’Etudes et de Recherches Aérospatiales (ONERA) M6 wing at Mach number 0.84 in terms of lift to drag ratio. Design/methodology/approach A computational fluid dynamics analysis of the wing-winglet configuration based on the ONERA M6 airfoil on drag reduction for different attack angles at Mach 0.84 was performed using analysis of systems Fluent. First, the best values of cant and sweep angles in terms of aerodynamic performance were selected by performing simulations. The analysis included cant angle values of 30°, 40°, 45°, 55°, 60°, 70° and 75°, while for the sweep angles 35°, 45°, 55°, 65° and 75° angles were used. The aerodynamic performance was measured in terms of the obtained lift to drag ratios. Findings The results showed that slight alternations in the winglet configuration can improve aerodynamic performance for various attack angles. The best lift to drag ratio for the winglet was achieved at a cant angle of 30° and a sweep angle of 65°, which caused a 5.33% increase in the lift to drag ratio. The toe-out angle winglets as compared to the toe-in angles caused the lift to drag ratio to increase because of more attached flow at its surface. The maximum value of the lift to drag ratio was obtained with a toe-out angle (−5°) at an angle of attack 3° which was 2.53% greater than the zero-toed angle winglet. Originality/value This work is relatively unique because the cant, sweep and toe angles were analyzed altogether and led to a significant reduction in drag as compared to wing without winglet. The wing model was compared with the results provided by National Aeronautics and Space Administration so this validated the simulation for different wing-winglet configurations.

Performance and control optimisations using the adaptive torsion wing

2012 ◽  
Vol 116 (1184) ◽  
pp. 1061-1077 ◽  
Author(s):  
R. M. Ajaj ◽  
M. I. Friswell ◽  
W. G. Dettmer ◽  
G. Allegri ◽  
A. T. Isikveren
Keyword(s):  
Structural Model ◽  
Torsional Stiffness ◽  
Load Path ◽  
Aerodynamic Efficiency ◽  
Roll Control ◽  
Novel Concept ◽  
And Control ◽  
Multidisciplinary Design Optimisation ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract This paper presents the Adaptive Torsion Wing (ATW) concept and performs two multidisciplinary design optimisation (MDO) studies by employing this novel concept across the wing of a representative UAV. The ATW concept varies the torsional stiffness of a two-spar wingbox by changing the enclosed area through the relative chordwise positions of the front and rear spar webs. The first study investigates the use of the ATW concept to improve the aerodynamic efficiency (lift-to-drag ratio) of the UAV. In contrast, the second study investigates the use of the concept to replace conventional ailerons and provide roll control. In both studies, the semi-span of the wing is split into five equal partitions and the concept is employed in each of them. The partitions are connected through thick ribs that allow the spar webs of each partition to translate independently of the webs of adjacent partitions and maintain a continuous load path across the wing span. An MDO suite consisting of a Genetic Algorithm (GA) optimiser coupled with a high-end low-fidelity aero-structural model was developed and employed in this paper.

scholarly journals Shock Reduction through Opposing Jets—Aerodynamic Performance and Flight Stability Perspectives

2019 ◽  
Vol 10 (1) ◽  
pp. 180 ◽  
Author(s):  
Shagufta Rashid ◽  
Fahad Nawaz ◽  
Adnan Maqsood ◽  
Rizwan Riaz ◽  
Shuaib Salamat
Keyword(s):  
Pressure Ratio ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Flight Stability ◽  
Supersonic Regime ◽  
Free Stream Mach Number ◽  
Drag Ratio ◽  
First Time ◽  
Lift To Drag Ratio

In this research paper, investigations of counter flow (opposing) jet on the aerodynamic performance, and flight stability characteristics of an airfoil with blunt leading-edge in supersonic regime are performed. Unsteady Reynolds-Averaged Navier-Stokes ( U R A N S ) based solver is used to model the flow field. The effect of angle of attack ( α ), free-stream Mach number ( M ∞ ), and pressure ratio ( P R ) on aerodynamic performance of airfoil with and without jet are compared. The results indicate that the opposing jet reduces drag from 30 % to 70 % , improves the maximum lift-to-drag ratio from 2.5 to 4.0, and increases shock stand-off distance from 15 % to 35 % depending on flow conditions. The effect of opposing jet on longitudinal flight stability characteristics, studied for the first time, indicate improvement in dynamic stability coefficients ( C m q + C m α ˙ ) at low angles of attack. It is concluded that the opposing jet can help mitigate flight disturbances in supersonic regime.

scholarly journals An Aerodynamic Design Method to Improve the High-Speed Performance of a Low-Aspect-Ratio Tailless Aircraft

2021 ◽  
Vol 11 (4) ◽  
pp. 1555
Author(s):  
Zhongyuan Liu ◽  
Lie Luo ◽  
Binqian Zhang
Keyword(s):  
Aspect Ratio ◽  
High Speed ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Pitching Moment ◽  
Aerodynamic Design ◽  
Linear Superposition ◽  
Low Aspect Ratio ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper puts forward an aerodynamic design method to improve the high-speed aerodynamic performance of an aircraft with low-aspect-ratio tailless configuration. The method can ameliorate the longitudinal moment characteristics of the configuration by designing and collocating the key section airfoils with the constrains of fixed parameters of planform shape and capacity. Firstly, the effect of twisting the wing, fore-loading and aft-reflexing key section airfoils on the high-speed aerodynamic performance of the configuration is evaluated by high-fidelity numerical methods, and quantified by defining trimming efficiency factors. Then, a linear superposition formula is obtained by analyzing the effect rule of trimming efficiency factor, and based on the formula the design and collocation methods of key section airfoils are achieved. According to the methods, a trimmed configuration is obtained. The results of computational fluid dynamics (CFD) and wind tunnel tests show that the trimmed configuration has smaller zero-lift pitching moment and higher available lift-to-drag ratio than the initial configuration at cruise, besides the trimmed configuration achieves the design principle raised for tailless configuration, which can be described as the zero-pitching moment, cruising design lift coefficient, and maximum lift-to-drag ratio are coincident. In addition, at off-design conditions, the trimmed configuration shows favorable drag divergence characteristics, satisfactory aerodynamic characteristics at medium-altitude maneuvering condition, and good stall and pitching-moment performance at low speed state.

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