Conventional Wing Research Articles

Design, development and ground testing of hingeless elevons for MAV using piezoelectric composite actuators

A design methodology is presented to develop the hingeless control surfaces for MAV using adhesively bonded Macro Fiber Composite (MFC) actuators. These actuators have got the capability to deflect the trailing edge surfaces of the wing to attain the required maneuverability, besides achieving the set aerodynamic trim condition. A scheme involving design, analysis, fabrication and testing procedure has been adopted to realize the trailing edge morphing mechanism. The stiffness distribution of the composite MAV wing is tailored such that the induced deflection by piezoelectric actuation is approximately optimized. Through ground testing, the proposed concept has been demonstrated on a typical MAV structure. Electromechanical analysis is performed to evaluate the actuator performance and subsequently aeroelastic and 2D CFD analyses are carried out to see the functional requirements of wing trailing edge surfaces to behave as elevons. Efforts have been made to obtain the performance comparison of conventional control surfaces (elevons) with morphing wing trailing edge surfaces. A significant improvement in lift to drag ratio is noticed with morphed wing configuration in comparison to conventional wing. Further, it has been shown that the morphed wing trailing edge surfaces can be deployed as elevons for aerodynamic trim applications.

Chin wing osteotomy for the correction of hyper-divergent skeletal class III deformity: technical modification

t d p s ( i n T he chin wing osteotomy has opened a new perspective for he management of skeletal class III deformities.1,2 When ombined with a LeFort I osteotomy, it can often obviate a agittal split osteotomy and its potential deleterious effects n both the temporomandibular joint and the dimensions of he pharyngeal airway, while it restores facial and occlusal armony with long-term stability. The conventional chin wing osteotomy comprises the hole mandibular basal border. In patients with hypodiverent class III deformities the chin wing is set back along the andibular border, often in association with a wedge excision f the chin. Hyperdivergence requires a chin wing setback lus anticlockwise rotation around the pogonion, with or ithout an associated wedge excision. In the case of hyperdiergence, the chin wing setback tends to require the excision f its most posteroinferior aspect to avoid unaesthetic distorion of the angle’s contour (Fig. 1).

Optimal Low-Drag Wing Planforms for Tractor-Configuration Propeller-Driven Aircraft

This paper proposes novel wing planforms that reduce induced drag by exploiting the slipstream in aircraft driven by propellers in tractor configuration. The novel planforms are determined by optimization through an extended lifting-line theory that accounts for slipstream effects and an optimizer that includes the option of using an appropriate number of Bézier polynomial weights as control parameters describing wing planform. The optimization package written for the purpose (PROWING) minimizes a user-selected cost function, subject to a wide class of geometric and mechanical constraints on such variables as root chord, tip chord, span, wing area, bounds on wing twist and chord, airfoil profiles, root bending moment, etc. A general feature of the optimal wing planforms so generated is that the chords are shorter within the slipstream and longer on either side of it. For a wing of aspect ratio 12 and prescribed wing area, PROWING predicts that an optimal planform can reduce induced drag by about 9.15%, with a maximum local wing chord variation of about 37% over a conventional reference wing. PROWING-based optimal planforms have been assessed in two ways: 1) by an Euler code that includes a blade-element theory module for the propeller and accounts for the aerodynamic effect of the propeller slipstream on wing planform; and 2) by a Reynolds-averaged Navier–Stokes simulation coupled to the blade-element theory module. Both assessments confirm that the class of planforms proposed here reduce drag but with slight differences, which is not unexpected because of the different assumptions underlying the different methods.

Wing weight model for conceptual design of nonplanar configurations

Unconventional aircraft designs, such as nonplanar wings, are being considered for the next generation of transport aircraft. In order to determine the suitability of such designs, conceptual design tools are needed which are both sensitive to these unconventional configurations and capable of obtaining results rapidly. Wings represent a large contribution to an aircraft's empty weight and there are many commonly used conceptual design tools which can accurately estimate this component's weight for conventional designs. However, nonplanar wings can have very different aerodynamic loadings and structural details so existing models cannot be easily extended to treat these complexities. This paper shows the development of a conceptual-level wing weight model which combines a fully-stressed cross-section method with an equivalent beam finite-element structural solver using loads derived from a nonplanar vortex-lattice method. This model is able to obtain accurate aerodynamic loadings for nonplanar wings and can model the statically indeterminate structure of closed wing configurations. It was shown to be as accurate as current approaches when analyzing conventional wings and it is able to show the details of nonplanar wing structures. This model will enable more meaningful multidisciplinary analyses of both conventional and unconventional wing designs by accurately and rapidly predicting both the weight and internal structural details of these designs.

Analysis and design of lattice materials for large cord and curvature variations in skin panels of morphing wings

In the past few decades, several concepts for morphing wings have been proposed with the aim of improving the structural and aerodynamic performance of conventional aircraft wings. One of the most interesting challenges in the design of a morphing wing is represented by the skin, which needs to meet specific deformation requirements. In particular when morphing involves changes of cord or curvature, the skin is required to undergo large recoverable deformation in the actuation direction, while maintaining the desired shape and strength in the others. One promising material concept that can meet these specifications is represented by lattice materials. This paper examines the use of alternative planar lattices in the embodiment of a skin panel for cord and camber morphing of an aircraft wing. We use a structural homogenization scheme capable of capturing large geometric nonlinearity, to examine the structural performance of lattice skin concepts, as well as to tune their mechanical properties in desired directions.

Calibration and Use of -Hole Velocity Probes

A generalized calibration process is presented for multihole, pressure-based velocity probes that is independent of the number of holes and probe geometry, allowing the use of probes with large numbers of holes. The calibration algorithm is demonstrated at low speeds with a conventional seven-hole pressure probe and a novel 19-hole pressure probe. Because the calibration algorithm is independent of probe configuration, it is very tolerant of data corruption and imperfections in the probe-tip geometry. The advantages of using probes with large numbers of holes is demonstrated in a conventional wing wake survey. The 19-hole probe offers a higher angular sensitivity than a conventional seven-hole probe and can accurately measure velocity components even when an analytical calibration scheme is used. The probe can also provide local estimates of the diagonal components of the crossflow velocity gradient tensor in highly vortical flows.

The Bionic Wing with Winglet in Near Space Aerodynamic Analysis

With reference to a certain type of flying drones with imitation airfoil design a seagull flat wings and on the basis of its wing tip winglet in this paper. Through to the numerical simulation of two wings, it is concluded that the bionic wing aerodynamic performance is superior to the conventional airfoil wing, after adding wing tip winglet bionic wings effectively reduced the downwash velocity, reduce the induced drag, makes the wing aerodynamic performance is improved. Provide theoretical reference for the design of the uav wing

Aerodynamic Characteristics Simulation Analysis of a Certain Type Changed Wing Drone Aircraft Based on CFD

This paper aims at the change of the whole machine aerodynamic characteristics after a certain conventional type drone aircraft changing plateau type large wings , using CFD technology to establish the nomal type and plateau type model, doing numerical simulation calculation of the whole machine's aerodynamic performance under the condition of no-load, using the simulation calculation results and combined with actual flight data, compared and evaluated the aerodynamic characteristics of the drone aircraft installed different airfoil, the results show that change plateau type large wings, obviously improve the lift-to-drag performance of the whole machine, increase the range of effective attack angle, and the little change of flight performance, scientific and feasible.

Performance of a Three-Dimensional Morphing Wing and Comparison with a Conventional Wing

In this paper, a morphing-wing concept based on compliant ribs is considered as a replacement for conventional ailerons and its performance is investigated. The roll performance of the three-dimensional morphing-wing solution for different design speeds and under structural and strength constraints is analyzed. The design approach uses optimization techniques and considers the three-dimensional aerostructural behavior. The results show the possibility of producing sufficient roll control authority with a morphing solution, thus replacing conventional ailerons up to a design speed of . In a further step, the weight of the system as a function of the produced rolling moment is compared with the one of a conventional system. The obtained relations offer an estimation of the weight penalties associated with morphing. This estimation can be useful in the preliminary design of morphing aircraft.

Static and Dynamic Analysis of Aluminium Composite in Wing Section Using ANSYS

The cold of this cardboard is to abstraction and analyze the amount accustomed accommodation and weight accumulation of blended aircraft (Aluminium Silicon Carbide) addition with that of Aluminium wing and appropriately access the acceptable aircraft addition of minimum weight accomplished of address a accustomed changeless amount after failure. And also this paper presents a model and a static analysis of the aircraft wing, using the finite element software ANSYS. The geometry was created in CATIA V5 R18 and imported. The static and model analysis are carried out in analysis software ANSYS. The result of from the static analysis refers to the total deformation, equivalent stress, shear stress and shear intensity on the skin of the aircraft wing. The model analysis will be carried out to find out the first six modes of vibrations and the different mode shape in which wing can deform without the application of load. Compared to the conventional Aluminium wing, the hybridized composite wing experience far lower stresses and the aircraft wing weight nearly 40% and 50% lower stress.

Computational and Experimental Validation of the Active Morphing Wing

An advanced computational and experimental analysis has been performed upon a conventional aircraft wing with two outboard morphing partitions that are variable in twist and dihedral angles. Results are generated with the intention of drawing meaningful comparisons with initial trends in aerodynamic and structural efficiency that have been observed in previous optimization studies. Computational results are obtained with the DLR, German Aerospace Center TAU computational fluid dynamics code, both for an aircraft wing in high-speed flight and for a wing modeled at low speed with wind-tunnel wall constraints. An experimental testing has been performed at the University of Bristol low-speed wind tunnel. An outer-twist variation of and dihedral angles from planar up to 90 deg C-wing geometries are tested for a range of incidence angles. Results demonstrate varying levels of agreement between each form of analysis method, and offer insight into the aerodynamic and structural tradeoff required to select an optimal configuration.

COMPARATIVE INVESTIGATION OF VLM CODES FOR JOINED-WING ANALYSIS

The Vortex lattice method (VLM) is a popular aerody namic analysis method used at the early stages of a ircraft design. In this paper a comparative investigation of several computer progr ams applying the VLM is carried out and their abili ty to simulate non conventional wing configurations is evaluated. It w as found that Athena Vortex Lattice (AVL) code calc ulated the most correct results, but other programs like Tornado provide useful supp lemental information.

Air Catapult Transportation

The current flight passenger-transport and cargo systems have reached the peak of their development. In the last 30 years there has been no increase in speed or reductions in trip costs. The transportation industry needs a revolutionary idea, which allows jumps in speed and delivery capability, and dramatic drops in trip price. The author offers a new idea in transportation in which trip (flight) time practically does not depend on distance, and vehicle load capability doubles and has a driving engine that is located on the ground and can use any cheap source of energy. The author develops the theory and provides computations for project which contains five subprojects united the common idea: acceleration of the air vehicle on ground and continuation of flight by inertia (high speed catapulting). The initial speed is 290 - 6000 m/s, the range is 50 -10000 km (short, average, and long distances). Short transport system has range 50-70 km, for example: city - sub-city, strait and air bridges such as across the Straits of Gibraltar 16 km, the English Channel 40 km, Bering Straits 100 km (Russia-America), Sakhalin-Asia 20 km, Russia-Japan, etc. The long distance has range up 10000 km such as New York-Paris 5838 km, Washington-London 7373 km, San-Francisco - Tokyo 8277 km, San-Francisco - Vladivostok (Russia) 8377 km, New York - Moscow 7519 km, Moscow - Beijing 5800 km, Moscow - Tokyo 7487 km, New York - Berlin 6392 km, and so on. The offered catapult system having length of 400 km can be used as the space launch system which decreases the space launch cost in hundreds of times. That also may be used as the new conventional high speed (up 1000 km/h) transport system between cities. That will be significantly cheaper than used MagLev (Magnetic Levitation) systems, because suspending of the vehicle used the conventional wing. The offered system may be also used for the mass launch of bombs (projectiles) in war.

Experimental study on the lift generated by a flapping rotary wing applied in a micro air vehicle

An experimental study was conducted to further validate whether the newly proposed flapping rotary wing is suitable for micro air vehicle design. First, the effects of two main kinematical parameters (flapping frequency and initial angle of attack) of flapping rotary wing on lift generation were discussed. It was found that a higher lift can be generated by flapping rotary wing through increasing flapping frequency at a proper initial angle of attack. Second, effect of coupled flapping motion with rotating motion on lift generation was analyzed. It is important that a larger lift was generated by flapping rotary wing than the superposition lifts from purely flapping and purely rotating motions when the initial angle of attack was less than a critical value. Finally, the comparison of the capability of lift generation from the flapping rotary wing and conventional rotary wing was given. It was indicated that the lift from flapping rotary wing was larger than that from conventional rotary wing in the range of Reynolds number from 2600 to 5000 as long as Strouhal number was determined appropriately. The present work suggests that flapping rotary wing may be a feasible and promising wing layout used in the design of micro air vehicle in terms of lift generation.

Design and Motion Control of Fully Variable Morphing Wings

The ability to vary the geometry of a wing to adapt to different flight conditions can significantly improve the performance of an aircraft. However, the realization of any morphing concept will typically be accompanied by major challenges. Specifically, the geometrical constraints that are imposed by the shape of the wing and the magnitude of the aerodynamic and inertia loads make the usage of conventional mechanisms inefficient for morphing applications. This paper presents the design of a novel underactuated parallel mechanism, which addresses such concerns. This mechanism, which can be set up in a modular fashion, offers controlled motion in all six spatial degrees of freedom while providing multiple degrees of fault tolerance with only four actuators. The main feature of the design is the usage of active and passive linearly adjustable members to replace the structure of a conventional wing box. These members provide the necessary stiffness and load-bearing capabilities for the wing. With the exception of the skin no additional structure would be required, leading to a relatively light-weight design for the morphing wing. Additionally, an optimal motion control algorithm for minimum energy actuation is proposed based on the kinematics and statics of the mechanism. Finally, the effectiveness of the proposed design and motion control is demonstrated through a simulation followed by the presentation of a multimodule prototype for a wing tip morphing application.

Wing mass estimation algorithm for medium range box wing aircraft

AbstractA procedure for defining an empirical formula for the mass estimation of the fore and aft wings field Uof a medium range box wing aircraft is described. The procedure is based upon the work of Howe for estimating the wing mass of conventional cantilever wing aircraft. The paper outlines the procedure used to relate conventional cantilever wings to box wing aircraft wings. Using a vortex lattice tool, finite element methods and regression analysis, the modification performed on the coefficient in Howe’s method to enable its use on a medium range box wing aircraft is outlined. The results show that the fore and aft wings would use the same correction coefficient and that the aft wing would therefore be lighter than the fore wing on a medium range box wing aircraft.

Multi-objective optimization procedure for the wing design at cruise and low-speed conditions

The procedure for wing aerodynamic design based on the algorithm of simultaneous multiregime optimization of cruise and low-speed performance is considered. The method is based on the combination of fast direct methods for subsonic and transonic wing analysis, geometry variation module and the optimization procedure. The description of all the components and examples of practical application of the developed technique for design of the conventional medium-haul airplane wing and the ‘Flying Wing’ configuration are presented.

A Comparative Evaluation of Early Stent Occlusion Among Biliary Conventional Versus Wing Stents

Conventional plastic stents with a lumen typically have limited patency. The lumenless wing stent was engineered to overcome this problem. The objective of this study was to compare the incidence of early stent occlusion (symptomatic occlusion/cholangitis necessitating re-insertion within 90 days) for wing stents and conventional plastic stents. Patients with biliary pathology treated with plastic biliary stenting during the period 2003-2009 comprised the study cohort. Patients who had at least one biliary wing stent placed comprised the wing stent group, whereas patients who underwent only conventional stent plastic placement comprised the conventional stent group. Patients were stratified by indication: benign biliary strictures (group 1), malignant biliary strictures (group 2), or benign biliary non-stricture pathology (group 3). The association of stent type with the occurrence of primary outcome by indication was analyzed by use of multivariable logistic regression. Three-hundred and forty-six patients underwent 612 ERCP procedures with placement of plastic biliary stent(s). On multivariate analysis, early stent occlusion did not differ between the wing and conventional groups in groups 1, 2, and 3. Among patients who achieved primary outcome in group 2, significantly fewer patients in the wing group had cholangitis (6.7% vs. 39.1%, P = 0.03). Among patients who achieved primary outcome in group 3, significantly fewer patients in the wing group had cholangitis (10% vs. 50%, P = 0.03). Early stent occlusion was similar for wing stents and conventional plastic stents. Wing stents, however, were associated with a lower incidence of cholangitis in patients with malignant biliary obstruction and benign non-stricturing biliary pathology.

A Proposal for a New Type of Integral Abutment with Seismic Energy Dissipation Capabilities

In this study a seismic isolated bridge is re-designed according to the current Codes' provisions to comprise an integral bridge system. A new type of abutment, which has the ability to accommodate both serviceability and earthquake resistance requirements of the bridge, is exploited in this bridge system. The abutment's web consists of transversely directed reinforced concrete (R/C) walls which are rigidly connected to the deck while the deck slab is extended towards the approach embankment and is rigidly connected with two pairs of walls. The walls are constructed in a concrete box-shaped substructure, which replaces the conventional wing walls and retains the backfill material. The design o f the restraining abutment provides a hierarchy of the resistances of its structural components aiming at the development of plastic hinges at the walls' top and bottom. The foundation of the abutment is designed to have adequate capacity to withstand the in-service and seismic loading of the abutment. The investigation showed that the seismic actions of the piers of the integral bridge are effectively reduced, as part of the induced seismic energy is transmitted and dissipated by the earthquake-resistant abutment. The reductions in the seismic actions lead to cost-effective and smaller cross-sections of the piers and their foundations which also serve aesthetics.

Sensitivity of an asymmetric 3D diffuser to vortex-generator induced inlet condition perturbations

Modifications of the turbulent separated flow in an asymmetric three-dimensional diffuser due to inlet condition perturbations were investigated using conventional static pressure measurements and velocity data acquired using magnetic resonance velocimetry (MRV). Previous experiments and simulations revealed a strong sensitivity of the diffuser performance to weak secondary flows in the inlet. The present, more detailed experiments were conducted to obtain a better understanding of this sensitivity. Pressure data were acquired in an airflow apparatus at an inlet Reynolds number of 10,000. The diffuser pressure recovery was strongly affected by a pair of longitudinal vortices injected along one wall of the inlet channel using either dielectric barrier discharge plasma actuators or conventional half-delta wing vortex generators. MRV measurements were obtained in a water flow apparatus at matched Reynolds number for two different cases with passive vortex generators. The first case had a pair of counter-rotating longitudinal vortices embedded in the boundary layer near the center of the expanding wall of the diffuser such that the flow on the outsides of the vortices was directed toward the wall. The MRV data showed that the three-dimensional separation bubble initially grew much slower causing a rapid early reduction in the core flow velocity and a consequent reduction of total pressure losses due to turbulent mixing. This produced a 13% increase in the overall pressure recovery. For the second case, the vortices rotated in the opposite sense, and the image vortices pushed them into the corners. This led to a very rapid initial growth of the separation bubble and formation of strong swirl at the diffuser exit. These changes resulted in a 17% reduction in the overall pressure recovery for this case. The results emphasize the extreme sensitivity of 3D separated flows to weak perturbations.