Wingtip Devices Research Articles

Evaluation of traditional and slotted winglets for enhanced aerodynamic efficiency

Minimizing drag is a critical focus in aviation, significantly influencing energy efficiency and performance. Lift-induced drag accounts for approximately 40% of total drag during cruise flight and 80%–90% during takeoff phase. Enhancing the coefficient of lift-to-drag ratio which is also termed as aerodynamic efficiency is a proven approach to reducing energy consumption in aircraft and unmanned aerial vehicles. Wingtip devices, such as winglets, offer a practical solution by mitigating induced drag generated by wingtip vortices. This study investigates the aerodynamic performance of three configurations: a plain wing, a wing with a traditional winglet, and a wing with a slotted winglet. The analysis was conducted using computational fluid dynamics software at angles of attack ranging from −4° to 12°, with velocities of 20 and 270 m/s, corresponding to Reynolds numbers of 2.5 × 106 and 3.3 × 107, respectively. Results demonstrated that the traditional winglet achieved a 4% average improvement in aerodynamic efficiency, while the slotted winglet exhibited a 3.16% enhancement over the plain wing. Energy consumption was reduced by 4% and 3.16% with traditional and slotted winglets, respectively. These findings validate the effectiveness of winglets in improving aerodynamic efficiency and provide insight for optimizing wingtip device design.

Exploration of bio-inspired wingtip devices for low aspect ratio wing

Abstract This study investigates the performance of low aspect ratio wing by incorporating bio-inspired wingtip devices, aiming to enhance the flying characteristics of micro air vehicles. The S5010 profiled wing, with an aspect ratio of 1.0, is selected as the reference wing. The wingtip devices are designed as flat plates, with a taper ratio of 0.5, featuring rounded leading and trailing edges. These devices are attached to the wingtip in a planar manner, thereby creating slots on the wingtip. Such an approach is intended to replicate the wingtip slot observed in the structure of primary feathers of soaring birds during flight, potentially providing aerodynamic benefits. In this study, four different winglet configurations are fabricated, and investigations are carried out in a subsonic wind tunnel at a Reynolds number range of 7 × 104 to 11 × 104. The results show significant improvements in lift slope, maximum lift coefficient, drag, lift-to-drag ratio, and pitching moment for all winglet configurations compared to the baseline. Furthermore, the study also investigates the effectiveness of winglet configurations by varying the number of attachments to the wingtip and their lengths. It is observed that configurations with a higher number of attachments show a more significant reduction in induced drag and upward pitching tendency than configurations with fewer attachments. Additionally, the performance of wing configurations is strongly affected by the Reynolds number, and it improves as the Reynolds number increases.

Experimental Exploration of Bioinspired Planar Wingtip Devices for a Flat-Plate Wing in the Low Reynolds Number Regime

Experimental Exploration of Bioinspired Planar Wingtip Devices for a Flat-Plate Wing in the Low Reynolds Number Regime

Effects of endplate designs on the performance of Savonius vertical axis wind turbine

In aerodynamic studies, endplates or wingtip devices play a crucial role in enhancing the performance of airfoil blades and minimizing losses. This is particularly important for wind turbines, especially the drag-type Savonius turbine. This paper aims to investigate the effects of different endplate designs. Both experimental works and numerical simulations were conducted on a Savonius rotor with an aspect ratio of 1. A total of eight different endplate geometries and sizes were investigated. The mechanical torque and rotational speed were measured experimentally under various loads with an incoming wind speed of 5.89 m/s. The coefficient of torque (CT) and coefficient of power (CP) were calculated in both the experiments and simulations. The simulation was first validated using data from the literature, and flow characteristics were then scrutinized. The results indicate that the endplates greatly impact the turbine performance, with improvements of up to 299.7 % compared to a turbine without endplates from the experiment. The endplates help prevent flow leakage near the blade edges. In addition to tip losses reducing turbine performance, aerodynamic parasitic drag also contributed to a decrease in CP for the full endplate. The relationship between the aerodynamic parasitic drag with TSR is also reported. By implementing a well-designed endplate, these adverse effects can be mitigated.

Aerodynamic Study of Different Types of Wingtip Devices

The economic system of the 21st century requires technological solutions that ensure economical and sustainable passenger and freight transport, also by air. To this end, aircraft manufacturers are constantly working to make their aircraft as economical as possible.The aim of the research is to examine the effectiveness of the CFD simulation programs by conducting wind tunnel tests. This research also studies different types of wingtip devices then compares the results to determine the most effective one in terms of aerodynamical drag reduction. In the course of the research, we test wingtip devices of various designs in a self-built wind tunnel, and then compare the measured data with the results of the computer simulation.

Influence of Different Wingtip Devices on Aerodynamic Characteristics of UAV

The wingtip device plays an important role in increasing the range of UAVs because the winglets can effectively reduce the induced drag. The purpose of this paper is to explore the influence of wingtip device parameters on the lift-to-drag ratio of UAVs. Using the Fluent analysis system, the drag reduction performance of the winglet-winglet structure based on a UAV was analyzed at different angles of attack. Firstly, from the perspective of aerodynamic performance, the optimal cant and sweep angles of the blended winglets were selected by simulations. Then, the best-blended winglet and the blended split were simulated and analyzed, and the difference between the two on the lift-to-drag ratio and the flow field around the wing were compared. Compared with the traditional wind tunnel test, the CFD technology used greatly shortens the research cost and experimental cycle and provides help for the design of the UAV wingtip work.

Aerodynamic performance of semi-wing with multiple winglets operating at low- and medium-range Reynolds numbers

Birds have traits that can induce better aerodynamic efficiency along with high manoeuvring capability during its flight, which could be shared with unmanned aerial vehicles for improving their aerodynamic performances. One such feature of the wing tip, i.e. the primary feathers of the birds could be an effective geometrical feature to reduce the wing tip vortices. This paper presents the bio-inspired wing tip devices, i.e. three-and four-tipped multiple winglets in reducing the strength of vortices emanating from the wing tip of the wing operating in the Reynolds number (Re) of [Formula: see text] and [Formula: see text]. Different combinations of both three- and four-tipped multiple winglets have been designed by varying the cant angle of each tip. Numerical simulations were carried out using Ansys-Fluent by solving three-dimensional Reynolds averaged Navier–Stokes formulations coupled with k-[Formula: see text] turbulence model to resolve the features of tip vortices. The simulation clearly indicates that there is a strong correlation between the size of the vortices and the aerodynamic performance parameters such as [Formula: see text], [Formula: see text] [Formula: see text], [Formula: see text]. The three- and four-tipped multiple winglets are effective in reducing vortex drag by disintegrating large strength vortex which occurs in the tip of straight wing, into few numbers of small strength vortices. When compared to straight wing, three-tipped multiple winglet with the cant angle combination of 50, 30, 10 improves the aerodynamic efficiency by 22% to 23% and the four-tipped winglet with the cant angle combination of 60, 50, 40, 30 enhances the same by 21% to 22% in the Re of [Formula: see text]. Even the longitudinal static stability has seen considerable improvement for four-tipped multiple winglets than three-tipped multiple winglets and straight wing.

Enhancing gust load alleviation performance in an optimized composite wing using passive wingtip devices: Folding and Twist approaches

This paper introduces an innovative numerical method for the design and optimization of high-aspect-ratio composite wings equipped with passive control systems, specifically, Folding WingTip (FWT) and Twist WingTip (TWT) devices. The aim is to enhance Gust Load Alleviation (GLA) performance in the baseline wing. Recent numerical studies have indicated that the inclusion of spring devices and wingtip modifications can offer additional benefits in alleviating gust loads during flight. The baseline wing is designed using a comprehensive multi-disciplinary optimization framework, taking into account aerostructural constraints and exploiting the anisotropic properties of composite materials. The proposed methodology integrates Finite Element (FE) software, an in-house Reduced Order Model (ROM) framework for nonlinear aeroelastic analyses, and Particle Swarm Optimization (PSO). This method, implemented in the Nonlinear Aeroelastic Simulation Software (NAS2) package, facilitated the streamlined design of composite wings with optimized aeroelastic and structural performance. The paper is divided into two main parts. Part 1 introduces a Multidisciplinary Design Optimization (MDO) approach for high-aspect-ratio composite wings, leading to the development of a baseline wing model. Part 2 evaluates the effectiveness of the FWT and TWT devices in alleviating gust loads on the baseline wing, with a focus on the Root Bending Moment (RBM) as a critical criterion for comparison. In wingtip modeling, geometrical nonlinearity is incorporated, and elastic trim is adjusted in each iteration to accommodate shape changes under load and aerodynamic panel movement is synchronized with structural adjustments.

Study on wing-tip device technology

Aircraft wings are designed to make airflow to travel faster on top and slower on bottom. The lift force is generated by the pressure difference between the top and bottom of the wing due to the Bernoulli principle. The downwash also provides lift due to Newtons third law. The wake vortex is the consequence of the production of lift. The spinning turbulent flow at the wing tip creates induced drag, and decreases the total aerodynamic efficiency of the aircraft. A wing tip device is a piece of extension of the wing attached to the wing tip vertically upward or downward. The idea of a wing tip device comes from nature, where engineers reference the wings of different types of birds. The main purpose of this design is to counter and reduce the total drag, allowing aircraft to optimize its aerodynamic performances to reduce fuel consumption. Different wing tip devices based on their structure design have various positive impacts on the aviation industry. In this article, the origin and the applications of wing-tip devices are discussed, offering a reference for the development of wing-tip devices.

Automation of Winglet Wings Geometry Generation for Its Application in TORNADO

The paper outlines an algorithm for the rapid aerodynamic evaluation of winglet geometries using the TORNADO Vortex Lattice Method. It is a very useful tool to obtain a first approximation of the aerodynamic properties and for performing an optimization of the geometry design. The TORNADO tool is used to systematically calculate the aerodynamic characteristics of various wings with wingtip devices. The fast response of the aerodynamic models allows obtaining a set of results in a remarkably short time. Therefore, the development of an algorithm to generate wing geometries with great ease and complex shapes is of vital importance for the mentioned optimization process. The basic outline of the algorithm, the equations defining the wing geometries, and the results for unconventional wingtip devices, such as blended winglets and spiroid winglets, are presented. Finally, this algorithm allows designing a procedure to study the improvement of aerodynamic properties (lift, induced drag, and moment). Some examples are included to illustrate the capabilities of the algorithm.

Development of an Active Wingtip for Aeroelastic Control

This paper presents the design of an innovative wingtip device actively actuated to control the aeroelastic loads, with a focus on the gust load alleviation. It summarizes the work carried out in the Clean Sky 2 AIRGREEN2 project, where the device was developed from scratch and reached a relevant technology readiness level with the full-scale prototype manufacturing and testing, compulsory to obtain the permit to fly. This paper describes the overall design of the devices, covering the structure, the aero-servo-elasticity characteristics of the whole aircraft, the actuation system design, the scaled wind tunnel testing, and the full-scale structural qualification tests. The paper proves how the development of a new item involves several disciplines simultaneously, remarking on the importance of an integrated approach to the new generation aircraft design.

Design of Non-Conventional Flight Control Systems for Bioinspired Micro Air Vehicles

This research focuses on the development of two bioinspired micro air vehicle (MAV) prototypes, based on morphing wings and wing grid wingtip devices. The morphing wings MAV tries to adapt the aerodynamics of the vehicle to each phase of flight by modifying the vehicle geometry, while the wing grid MAV aims to minimize the aerodynamic and weight penalty of these vehicles. This work focuses on the design methodology of the flight control system of these MAVs. A preliminary theoretical conceptual design was used to verify the requirements, wind tunnel tests were performed to determine aerodynamic characteristics, and suitable materials were selected. The hardware and software configuration designed for the control system, which fulfills the objective of adaptive and optimal control in the wingtip-based prototype of the wing grid, is described. Finally, the results of the flight control on the prototype MAVs are analyzed.

Correction to: Optimum Induced Drag of Wingtip Devices: The Concept of Best Winglet Design

Correction to: Optimum Induced Drag of Wingtip Devices: The Concept of Best Winglet Design

Optimum Induced Drag of Wingtip Devices: The Concept of Best Winglet Design

Optimum Induced Drag of Wingtip Devices: The Concept of Best Winglet Design

Aerodynamic Characteristics of a Straight Wing with a Spiroid Wingtip Device

Abstract Spiroid wingtip devices (WD) offer a promising way of improving the lift drag ratio of UAVs, but may on the other hand lead to negative aerodynamic interference of the wing with the WD and deterioration of the aerodynamic characteristics as compared to a wing without the WD. Determining the influence of the geometric parameters of a spiroid WD on aerodynamic wing characteristics, however, remains an understudied field. In our study, we investigated the influence of the following geometrical parameters on wing aerodynamic characteristics with WD: area, radius, camber angle, constriction, and pitch of the spiroid. We found that the positive effect of the WD is present at a relative radius > 0.05, as well as with an increase in the lift coefficient C L as a result of an increase in the proportion of inductive resistance. For example, with the Reynolds number Re = 2.1×105 for a rectangular wing with an aspect ratio θ = 5.12 equipped with a spiroid WD with =0.15 the quality gain is almost 10% at C L = 0.5, and at C L = 0.7 is almost 20% and at C L = 0.7 – almost 20% compared to a wing without WD. Moreover, we found that a change in the camber angle WD θ provides an increase in the derivative of the lift coefficient with respect to the angle of attack in the range from θ = 0° to θ = 130°. By changing the camber angle, it is possible to increase the lift drag ratio of the layout up to 7.5% at θ = 90° compared to θ = 0° at the Reynolds number Re = 2.1×105. From the point of view of ensuring maximum lift drag ratio and minimum inductive drag, the angle θ = 90° is the most beneficial.

Design And Analysis of CFD Geometry Configuration Canted Winglet Toward Aerodynamic Characteristic on Wing Profil of The UAV LSU-05

The wing is part of an aircraft or UAV which has a function as a major component of producing lift, therefore if a problem occurs such as a vortex at the end of the wing it will affect its performance capability. This study aims to determine the condition of the airflow, the value of induced drag, and the selection of the design of the wingtip devices on the wing profile of the UAV LSU-05. The method used is numerical or computational methods with CFD-based software to predict the aerodynamic characteristics and phenomenon of airflow around the wing with wingtip devices and without it. The model used in this study is a half-wing LSU-05 with NACA 4415 made with CATIA V5R20 software and the simulation uses ANSYS CFX 17.1. Based on the previous simulation results, it was found that the application of the canted winglet geometry to the wing profile of the UAV LSU-05 affects the coefficient lift (CL)/coefficient drag (CD) value and induced drag. Whereas the coefficient lift (CL)/coefficient drag (CD) value before using the canted winglet was 18.904 after application, increased to 21.616, this causes the induced drag value to change inversely with the coefficient lift (CL)/coefficient drag (CD) value where the value before the application was 30.4181 N to 29.0566 N.Keywords: Canted Winglet, CFD, Wing

Aerodynamic Design of Wingtip Devices Using Far-field Drag Decomposition

Computational Fluid Dynamics (CFD) has become widely used for civil aircraft. However, the commonly used wall integration method for drag prediction based on Reynolds- averaged Navier-Stokes (RANS) equations still has some shortcomings. Far-field drag decomposition (FDD) method was developed as an alternative to improve the drag prediction accuracy and to provide a powerful analysis tool. FDD is capable of decomposing the drag into viscous, shock, induced, and spurious drag components, which provides invaluable insight into the relationship between drag and flow phenomena. Despite all the strengths, FDD is seldom used for aerodynamic shape design and optimization. In this paper, FDD was used to design wingtip devices for a business aircraft. Five spiroid and one blended winglet were compared with baseline wing and tip-extension configuration. Results indicate that all drag components were quantified successfully and the trade-off between induced drag and other drag components was better explained. The spiroid winglet with new foil gives the lowest total drag and wave drag.

Numerical investigation of stall characteristics for winglet blade of a horizontal axis wind turbine

Wind energy is one of the renewable energy resources which is clean and sustainable energy and the wind turbine is used for harnessing energy from the wind. The blades are the key components of a wind turbine to convert wind energy into rotational energy. Recently, wingtip devices are used in the blades of horizontal axis wind turbine (HAWT), which decreases the vortex and drag, while increases the lift and thereby improve the performance of the turbine. In the present study, a winglet is used at the tip of an NREL phase VI wind turbine blade. Solidworks, Pointwise, and Ansys-Fluent are used for geometric modeling, computational grid generation, and CFD simulation, respectively. The computational result obtained using SST k-ω turbulence modeling is well validated with the experimental data of NREL at 5 and 7 m/s of wind speeds. Numerical investigation of stall characteristics is carried out for wingleted blade at higher turbulence intensity (21% and 25%) and angle of attack (00 to 300 at 50 intervals) at 7 m/s wind speed. The result found that wingletd blade delay stall to 150 for both the cases of turbulence intensity. Increasing the turbulence intensity increases the lift coefficient at stall angle but drag coefficient also increases and thus a lower aerodynamic performance (CL/CD ratio = 13) is obtained. Wingleted blade improves the performance as the intensity of vortices is smaller compared to baseline blade

Aerodynamic and Structural Design of a 2022 Formula One Front Wing Assembly

The aerodynamic loads generated in a wing are critical in its structural design. When multi-element wings with wingtip devices are selected, it is essential to identify and to quantify their structural behaviour to avoid undesirable deformations which degrade the aerodynamic performance. This research investigates these questions using numerical methods (Computational Fluid Dynamics and Finite Elements Analysis), employing exhaustive validation methods to ensure the accuracy of the results and to assess their uncertainty. Firstly, a thorough investigation of four baseline configurations is carried out, employing Reynolds Averaged Navier–Stokes equations and the k-ω SST (Shear Stress Transport) turbulence model to analyse and quantify the most important aerodynamic and structural parameters. Several structural configurations are analysed, including different materials (metal alloys and two designed fibre-reinforced composites). A 2022 front wing is designed based on a bidimensional three-element wing adapted to the 2022 FIA Formula One regulations and its structural components are selected based on a sensitivity analysis of the previous results. The outcome is a high-rigidity-weight wing which satisfies the technical regulations and lies under the maximum deformation established before the analysis. Additionally, the superposition principle is proven to be an excellent method to carry out high-performance structural designs.

Aerodynamic Investigation of a Horizontal Axis Wind Turbine with Split Winglet Using Computational Fluid Dynamics

Wind energy is one of the fastest growing renewable energy sources, and the most developed energy extraction device that harnesses this energy is the Horizontal Axis Wind Turbine (HAWT). Increasing the efficiency of HAWTs is one important topic in current research with multiple aspects to look at such as blade design and rotor array optimization. This study looked at the effect of wingtip devices, a split winglet, in particular, to reduce the drag induced by the wind vortices at the blade tip, hence increasing performance. Split winglet implementation was done using computational fluid dynamics (CFD) on the National Renewable Energy Lab (NREL) Phase VI sequence H. In total, there are four (4) blade configurations that are simulated, the base NREL Phase VI sequence H blade, an extended version of the previous blade to equalize length of the blades, the base blade with a winglet and the base blade with split winglet. Results at wind speeds of 7 m/s to 15 m/s show that adding a winglet increased the power generation, on an average, by 1.23%, whereas adding a split winglet increased it by 2.53% in comparison to the extended blade. The study also shows that the increase is achieved by reducing the drag at the blade tip and because of the fact that the winglet and split winglet generating lift themselves. This, however, comes at a cost, i.e., an increase in thrust of 0.83% and 2.05% for the blades with winglet and split winglet, respectively, in comparison to the extended blade.