Computational analysis and design of an aerofoil with morphing tail for improved aerodynamic performance in transonic regime

Abstract This article focuses on the aerodynamic design of a morphing aerofoil at cruise conditions using computational fluid dynamics (CFD). The morphing aerofoil has been analysed at a Mach number of 0.8 and Reynolds number of $3 \times 10^{6}$ , which represents the transonic cruise speed of a commercial aircraft. In this research, the NACA0012 aerofoil has been identified as the baseline aerofoil where the analysis has been performed under steady conditions at a range of angles of attack between $0^{^{\kern1pt\circ}}$ and $3.86^{^{\kern1pt\circ}}$ . The performance of the baseline case has been compared to the morphing aerofoil for different morphing deflections ( $w_{te}/c = [0.005 - 0.1]$ ) and start of the morphing locations ( $x_{s}/c = [0.65 - 0.80]$ ). Further, the location of the shock wave on the upper surface has also been investigated due to concerns about the structural integrity of the morphing part of the aerofoil. Based upon this investigation, a most favourable morphed geometry has been presented that offers both, a significant increase in the lift-to-drag ratio against its un-morphed counterpart and has a shock location upstream of the start of the morphing part.

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Lift Enhancement of NACA 4415 Airfoil using Biomimetic Shark Skin Vortex Generator

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.d9222.118419 ◽

2019 ◽

Vol 8 (4) ◽

pp. 9231-9234

Keyword(s):

Performance Enhancement ◽

Incident Angle ◽

Vortex Generator ◽

Leading Edge ◽

Vortex Generators ◽

Shark Skin ◽

Baseline Case ◽

Lift And Drag ◽

Drag Ratio ◽

Lift To Drag Ratio

An experimental study was conducted to investigate the aerodynamic performance of the NACA 4415 airfoil with and without passive vortex generators. The measurement has been carried out for three considered cases: smooth airfoil for baseline case, airfoil with triangular vortex generator and also airfoil with shark skin shape vortex generator. Both the triangular and shark skin vortex generators were located at 50% of chord from leading edge of the airfoil with a 20° counter-rotating incident angle. The experiments were conducted with Reynold’s number of 100,000. Overall, the results indicate that the lift and drag coefficients, and lift-to-drag ratio, for the airfoil with sharkskin vortex generator are comparatively higher than the other airfoils at some angles of attack. The findings can be applied in optimizing shark skin shape vortex generator for the airfoil performance enhancement.

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Dynamic Lift Coefficients for Spade Rudders on Yachts

10.5957/csys-2007-017 ◽

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.

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Aerodynamic Optimization of an Over-the-Wing-Nacelle-Mount Configuration

Modelling and Simulation in Engineering ◽

10.1155/2011/293078 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

Daisuke Sasaki ◽

Kazuhiro Nakahashi

Keyword(s):

Interference Effect ◽

Jet Engines ◽

Aerodynamic Design ◽

Aerodynamic Optimization ◽

High Lift ◽

Aerodynamic Efficiency ◽

Wing Geometry ◽

Aerodynamic Interference ◽

Drag Ratio ◽

Lift To Drag Ratio

An over-the-wing-nacelle-mount airplane configuration is known to prevent the noise propagation from jet engines toward ground. However, the configuration is assumed to have low aerodynamic efficiency due to the aerodynamic interference effect between a wing and a nacelle. In this paper, aerodynamic design optimization is conducted to improve aerodynamic efficiency to be equivalent to conventional under-the-wing-nacelle-mount configuration. The nacelle and wing geometry are modified to achieve high lift-to-drag ratio, and the optimal geometry is compared with a conventional configuration. Pylon shape is also modified to reduce aerodynamic interference effect. The final wing-fuselage-nacelle model is compared with the DLR F6 model to discuss the potential of Over-the-Wing-Nacelle-Mount geometry for an environmental-friendly future aircraft.

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Modification impact on aerodynamic performance of hypersonic waverider

The Aeronautical Journal ◽

10.1017/s0001924000005844 ◽

2011 ◽

Vol 115 (1168) ◽

pp. 325-334 ◽

Cited By ~ 3

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.

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

Applied Sciences ◽

10.3390/app11041555 ◽

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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Computational Investigation of a Novel Box-Wing Aircraft Concept

Applied Sciences ◽

10.3390/app12020752 ◽

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.

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Aerodynamic Analysis and Design of High-Performance Sails

10.5772/intechopen.99045 ◽

2021 ◽

Author(s):

Sean P. Caraher ◽

Garth V. Hobson ◽

Max F. Platzer

Keyword(s):

High Performance ◽

Aerodynamic Characteristics ◽

High Wind ◽

Analysis And Design ◽

Airfoil Section ◽

Hydrokinetic Turbines ◽

Ansys Cfx ◽

Thrust Production ◽

Drag Ratio ◽

Lift To Drag Ratio

High-performance sails, such as the ones used on the America Cup boats, require sails whose aerodynamic characteristics approach those of rigid wings, yet permit a reduction in sail area in high wind and sea conditions. To this end, two-cloth sails are coming into use. These sails are constructed out of an articulated forebody that is a truncated ellipse, the aft of which has sail tracks, or rollers, along the edges to accommodate the twin sails. As the sails on either side need to be of the same length, due to the requirement to sail on different tacks, the two cloth sections need to be of equal length. The requirement then is to have their clews separated and able to slide over each other. More importantly, the transition between the rigid mast section and sails needs to be as aerodynamically smooth as possible in order to reduce drag and hence maximize the lift to drag ratio of the airfoil section that is made up of the mast and twin sails. A computational analysis using ANSYS CFX is presented in this chapter which shows that the aerodynamic characteristics of this type of two-cloth sail are almost as good as those of two-element rigid wing sections. Optimum sail trim configurations are analyzed in order to maximize the thrust production. Applications may soon extend beyond competitive sailing purposes for use on sailing ships equipped with hydrokinetic turbines to produce hydrogen via electrolysis (energy ships). Additionally, high performance sails can be used onboard cargo ships to reduce overall fuel consumption.

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Aerodynamic Properties of Avian Flight as a Function of Wing Shape

Fluids Engineering ◽

10.1115/imece2005-83011 ◽

2005 ◽

Cited By ~ 4

Author(s):

Andrew I. March ◽

Charles W. Bradley ◽

Ephraim Garcia

Keyword(s):

Bird Species ◽

Commercial Aircraft ◽

Morphing Aircraft ◽

Avian Flight ◽

Induced Drag ◽

Aerodynamic Properties ◽

Flight Regimes ◽

Long Endurance ◽

Drag Ratio ◽

Lift To Drag Ratio

Presently, all man-made aircraft are optimized for one specific flight regime. Commercial aircraft fly at a specific cruising altitude at which they are most efficient, and military aircraft, which require excellent performance in many flight regimes are designed to be ‘good’ at all of them. A new concept in aviation, morphing aircraft, or aircraft that can fully change their shape, will allow for optimization at nearly any flight regime. This concept has been millennia in the making, well before mankind. Looking to various bird species, tails and wings can completely change shape to optimize their morphology for a given flight regime. Raptors, especially, have mastered the air in that they must out compete and overcome other birds while hunting. For soaring, these birds spread their wings fully to maximize their lift to drag ratio and maintain a low energy, long endurance flight. To maximize speed in a dive they will bring their wings close to their bodies to minimize drag. This study seeks to quantify the aerodynamic properties of the wing. From bird wings the aerodynamic properties of shape changing elastic structures can be understood. The coefficient of lift versus angle of attack plot of a bird wing is not like that of a typical airfoil, it has no distinct point where the wing stalls, instead the bird wing will twist into the flow. Additionally, the induced drag of an avian wing is significantly less than the theoretical induced drag on a wing predicted by the aspect ratio. A flow visualization around the slotted wingtips of a bird reveals smooth streaklines near the primary feathers. These feathers are canted downward and accordingly generate lift in the thrust direction of the wing, which acts to reduce the induced drag on the wing.

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