Airplane Wing Research Articles

A beam finite element for analysis of composite beams with the inclusion of bend-twist coupling

Material-induced bend-twist coupling in laminated composite beams has seen applications in engineered structures for decades, including airplane wings and turbine blades. Numerical studies and analytical formulations of the dynamics of bend-twist coupled laminated beams and plates have been investigated in recent years, yet can be cumbersome to implement quickly and efficiently. In early stages of design, employing a stiffness method approach to predict the load-deformation relationship and structural natural frequencies can be more efficient than developing a shell finite element model for each design iteration.A weak-form approach to the development of an accurate bend-twist coupled composite laminate beam element is presented herein. Comparisons are made between the stiffness matrix terms using the presented method and a shell finite element model of an idealized beam; the proposed method shows good agreement for a suite of beams with varying degrees of bend-twist coupling. The method is then extended to the calculation of natural frequencies by combining the new stiffness matrix with a corresponding consistent mass matrix to formulate the eigenvalue problem and shows very good agreement with both analytical and shell element solutions.

The modified design of aeroplane fuselage to overcome drag resistance acting due to flow of air

The design of aeroplane fuselage body is designed by using principle of aerofoil shape. The wings of aeroplane are in perfectly aerofoil shape, but main body is not in perfectly aerofoil shape. Thus increases projecting area for striking of fluid on aeroplane; this result into large drag force acting on the aeroplane. This paper is related with external design of aeroplane, describes the use of pipes with decreasing diameter with length. If the bunches of pipes are joined on entire external surface of aeroplane then the drag force due to air reduces with greatest amount and due to decreasing diameter air going through pipe ejects from another end of it and results into creating a force which helps to accelerate the aeroplane. The diameters of pipes are moderated as per cross section area of aeroplane. The drag force acting on the aeroplane is equally distributed to all pipes and its effect to decelerate aeroplane is nullifies with greatest amount. Thus if we implement this arrangement to external design then the total power consumption of aeroplane is greatly reduced.

A Method to Realize Accurate Dynamic Feedforward Control of a Spray-Painting Robot for Airplane Wings

The dynamic characteristic has an important effect on the motion precision of a robot and dynamic feedforward control is an effective approach to reduce the effect. However, it is difficult to realize the accurate dynamic feedforward control in an industrial servo system and determine the feedforward coefficients. This paper proposes a method to realize the accurate dynamic feedforward control of a spray-painting robot for airplane wings with large workspace and time-varying dynamics. The basic control method is still the feedback control system with dynamic feedforward compensation, which is the most widely used in industrial field. The control parameters of the closed-loop feedback control system are designed based on atlas method. Considering that only the acceleration and velocity feedforward compensations are provided in an industrial servo system, the mapping relationship between the complete dynamic model and the velocity and acceleration compensators is investigated. Then, the method to realize the accurate feedforward compensation in the industrial servo system is presented based on the complete dynamic model. For a complex robot without an accurate dynamic model, the approach to realize the accurate feedforward compensation is also discussed. The experiment on a physical prototype validates the effect of the proposed methods. This paper is very helpful for the practical control of robots in an industrial field.

Enhanced Corrosion and Wear Behavior of Nano Titanium Carbide Reinforced Polyurethane PMC Coating on Aluminium 7075

Aluminum 7075 has an extensive variety of utilization over different fields because of its intrinsic properties such as high ductility, high toughness, high strength and low density. It is being utilized broadly for structural parts in aviation industries to manufacture aeroplane wings, internal bearing and fuselage. In spite of having high strength to weight ratio, aluminium does not have good resistance against wear and corrosion.Surface coating technology is a well-known technique for improving the wear resistance and corrosion resistance of the coated substrate which can eliminate corrosion along with fretting and adhesive wear by providing suave surface..Generally, polyurethane (PU) coatings were done on engineering metals to provide corrosion protection; hence it is highly advantageous to coat it on aluminium 7075 to improve its corrosion resistance.Polyurethane coating technology offers excellent adhesion and corrosion resistance when compared with other traditional metal coatings such as electro plating, electroless plating, PVD, CVD etc. Polymer Matrix Composite (PMC) coatings were preferred to improve the wear resistance along with corrosion resistance on corrosive and low wear resistant metals such as copper alloys, mild steel, and aluminum alloys. In this paper, PMC coatings of polyurethane as matrix along with nano titanium carbide reinforcement were coated on Aluminium 7075 through physical deposition method. The nano TiC was blended with Epoxy polyamide (EP) and Polyurethane separately in different proportions (1%, 2% and 3%) with the help of mechanical stirrer. Epoxy polyamide along with TiC nano composite was first coated as a base coat on the Aluminium 7075 substrate at the pressure not exceeding 35bar. The polyurethane was coated as top coat along with nano titanium carbide as reinforcement on Aluminium 7075 in different volume percentage. Wear, corrosion and optical microscope studies were done. Micro hardness test reveals that the sample which was coated with 3% nano TiC along EP and 3% nano TiC & PU gives the highest hardness when compared to other samples. It is attributed to the fact that it contains the highest percentage of titanium carbide mixed to both the polyurethane and the epoxy polyamide when compared to the other samples which has nano TiC in either base coat or upper coat. Similarly, through salt spray test it was found that highest corrosion resistance was observed in the sample which was coated with nano TiC in both the EP and PU. The samples were also examined through optical microscope and test results were justified. The inclusion of nano titanium carbide to the polymer coating increases the coating hardness, wear resistance and corrosion resistance of the aluminium 7075.

Flow Control of Jets, Wakes and Separated Flows

Flow control is made passively or actively for the object flow to reduce or eliminate the flow separation, formation of vortex, the flow resistance, etc. For example, Parekh said that for active flow control triad there are three important subjects of the understanding of flow phenomena, controls and sensors, and actuators. By the way, now generally, it is desired to improve the Feedforward control by AI and establish the control method combining it and Feedback control. In this study, the flow control of jets, wakes and separated flows is examined with control method and some examples, such as the effects of nozzle shape and vortex generator, control and suppression of high speed jet noise by chevron nozzle, air-flow classification of fine solid particle, lift control of airplane wings, flow control of Notor helicopter without tail rotor, vector control of supersonic jet, etc. are shown.

The development of Serbian aviation and aviation signal stations and their significance on the Salonica front

The development of human society and human conscience has contributed to the general progress in different spheres. Man, observing the surroundings, has always tended to adjust the environment to his needs. Thus, at one point, looking into the sky, he experienced a desire to fly in the vast space above him and be free like a bird. Such ideas have not just been a dream, but represented a need to test the human capabilities, too. Hence he has started, initially in a primitive way, and later with more sophistication, to contrive mechanisms, which would take him into free and yet unexplored sky. The first balloon flight was performed out in the long gone year of 1783, when the Montgolfier brothers flew over Paris. George Cayley, an English engineer, carried out several flights between 1804 and 1853. He was the first to construct a flying machine with fixed wings and separate systems for take-off, motion and control. In 1874 Felix du Temple de la Croix, a navy officer, constructed a flying device resembling the wings of a bird, with a wheel retracting into the base, a propeller and a 6 HP motor. Clement Ader, a French engineer, constructed in 1890 a flying device called Eole powered by a steam engine with four cylinders, 20 HP and four propellers. Otto Lilienthal, a German civil engineer, managed to perform the first safe flight in history. His scientific approach was adopted by the Wright brothers. Orville and Wilbur Wright constructed the first 'successful' airplane in the world, whose flight on 17 December 1903 was fully controlled. Later on, they developed a fixed airplane wing and introduced electronic adjustments in the airplane.

A Numerical Study on the Excitation of Guided Waves in Rectangular Plates Using Multiple Point Sources

Ultrasonic guided waves are widely used to inspect and monitor the structural integrity of plates and plate-like structures, such as ship hulls and large storage-tank floors. Recently, ultrasonic guided waves have also been used to remove ice and fouling from ship hulls, wind-turbine blades and aeroplane wings. In these applications, the strength of the sound source must be high for scanning a large area, or to break the bond between ice, fouling and plate substrate. More than one transducer may be used to achieve maximum sound power output. However, multiple sources can interact with each other, and form a sound field in the structure with local constructive and destructive regions. Destructive regions are weak regions and shall be avoided. When multiple transducers are used it is important that they are arranged in a particular way so that the desired wave modes can be excited to cover the whole structure. The objective of this paper is to provide a theoretical basis for generating particular wave mode patterns in finite-width rectangular plates whose length is assumed to be infinitely long with respect to its width and thickness. The wave modes have displacements in both width and thickness directions, and are thus different from the classical Lamb-type wave modes. A two-dimensional semi-analytical finite element (SAFE) method was used to study dispersion characteristics and mode shapes in the plate up to ultrasonic frequencies. The modal analysis provided information on the generation of modes suitable for a particular application. The number of point sources and direction of loading for the excitation of a few representative modes was investigated. Based on the SAFE analysis, a standard finite element modelling package, Abaqus, was used to excite the designed modes in a three-dimensional plate. The generated wave patterns in Abaqus were then compared with mode shapes predicted in the SAFE model. Good agreement was observed between the intended modes calculated in SAFE and the actual, excited modes in Abaqus.

Effect of sub-zero treatment on fatigue strength of aluminum 2024

Challenge of change of alloy properties during service life of extra safety parts was always considered by industrialists and consequently researchers. Fuselage and wings of airplane repeatedly in ascent and descent is affected respectively by cooling to − 55°C and heating to room temperature. Hence, the effect of above temperature changes on tensile and fatigue strengths are unknown. In this study in laboratory, the situation of airplane body is tried to simulate and then the changes of microstructure and consequently the changes of tensile properties and hardness after holding for 10 and 4h were studied respectively in temperatures of − 60°C and − 196°C. Results showed that by using of sub-zero treatment, hardness is without change but tensile properties are increased to control specimen. In addition, after sub-zero treatment, the fatigue limit of the control specimen has reduced at least 20%.

Supercomputer redesign of aeroplane wing mirrors bird anatomy

Supercomputer redesign of aeroplane wing mirrors bird anatomy

Giga-voxel computational morphogenesis for structural design.

In the design of industrial products ranging from hearing aids to automobiles and aeroplanes, material is distributed so as to maximize the performance and minimize the cost. Historically, human intuition and insight have driven the evolution of mechanical design, recently assisted by computer-aided design approaches. The computer-aided approach known as topology optimization enables unrestricted design freedom and shows great promise with regard to weight savings, but its applicability has so far been limited to the design of single components or simple structures, owing to the resolution limits of current optimization methods. Here we report a computational morphogenesis tool, implemented on a supercomputer, that produces designs with giga-voxel resolution-more than two orders of magnitude higher than previously reported. Such resolution provides insights into the optimal distribution of material within a structure that were hitherto unachievable owing to the challenges of scaling up existing modelling and optimization frameworks. As an example, we apply the tool to the design of the internal structure of a full-scale aeroplane wing. The optimized full-wing design has unprecedented structural detail at length scales ranging from tens of metres to millimetres and, intriguingly, shows remarkable similarity to naturally occurring bone structures in, for example, bird beaks. We estimate that our optimized design corresponds to a reduction in mass of 2-5 per cent compared to currently used aeroplane wing designs, which translates into a reduction in fuel consumption of about 40-200 tonnes per year per aeroplane. Our morphogenesis process is generally applicable, not only to mechanical design, but also to flow systems, antennas, nano-optics and micro-systems.

Operation load estimation of chain-like structures using fiber optic strain sensors

The recent advancements in sensing technologies allow us to record measurements from target structures at multiple locations and with relatively high spatial resolution. Such measurements can be used to develop data-driven methodologies for condition assessment, control, and health monitoring of target structures. One of the state-of-the-art technologies, Fiber Optic Strain Sensors (FOSS), is developed at NASA Armstrong Flight Research Center, and is based on Fiber Bragg Grating (FBG) sensors. These strain sensors are accurate, lightweight, and can provide almost continuous strain-field measurements along the length of the fiber. The strain measurements can then be used for real-time shape-sensing and operational load-estimation of complex structural systems. While several works have demonstrated the successful implementation of FOSS on large-scale real-life aerospace structures (i.e., airplane wings), there is paucity of studies in the literature that have investigated the potential of extending the application of FOSS into civil structures (e.g., tall buildings, bridges, etc.). This work assesses the feasibility of using FOSS to predict operational loads (e.g., wind loads) on chain-like structures. A thorough investigation is performed using analytical, computational, and experimental models of a 4-story steel building test specimen, developed at the University of Southern California. This study provides guidelines on the implementation of the FOSS technology on building-like structures, addresses the associated technical challenges, and suggests potential modifications to a load-estimation algorithm, to achieve a robust methodology for predicting operational loads using strain-field measurements.

Temperature decline thermography for laminar\u2013turbulent transition detection in aerodynamics

Detailed knowledge about laminar–turbulent transition and heat transfer distribution of flows around complex aerodynamic components are crucial to achieve highest efficiencies in modern aerodynamical systems. Several measurement techniques have been developed to determine those parameters either quantitatively or qualitatively. Most of them require extensive instrumentation or give unreliable results as the boundary conditions are often not known with the required precision. This work introduces the simple and robust temperature decline method to qualitatively detect the laminar–turbulent transition and the respective heat transfer coefficients on a surface exposed to an air flow, according to patent application Stadlbauer et al. (Patentnr. WO2014198251 A1, 2014). This method provides results which are less sensitive to control parameters such as the heat conduction into the blade material and temperature inhomogeneities in the flow or blade. This method was applied to measurements with NACA0018 airfoils exposed to the flow of a calibration-free jet at various Reynolds numbers and angles of attack. For data analysis, a post-processing method was developed and qualified to determine a quantity proportional to the heat transfer coefficient into the flow. By plotting this quantity for each pixel of the surface, a qualitative, two-dimensional heat transfer map was obtained. The results clearly depicted the areas of onset and end of transition over the full span of the model and agreed with the expected behavior based on the respective flow condition. To validate the approach, surface hotfilm measurements were conducted simultaneously on the same NACA profile. Both techniques showed excellent agreement. The temperature decline method allows to visualize laminar–turbulent transitions on static or moving parts and can be applied on a very broad range of scales—from tiny airfoils up to large airplane wings.

Toward a prescriptive theory of dynamic capabilities: connecting strategic choice, learning, and competition

The field of strategy has mounted an enormous effort to understand, define, predict, and measure how organizational capabilities shape competitive advantage. While the notion that capabilities influence strategy dates back to the work of Andrews (1971, The Concept of Corporate Strategy, Irwin: Homewood), attempts to formalize a “capabilities-based” approach to strategy only began to take shape in the past 20 years. In particular, the publication of Teece and Pisano (1994, Industrial and Corporate Change, 3(3), 537–556), Teece et al. (1997, Strategic Management Journal, 3, 509–533), and Eisenhardt and Martin (2000, Strategic Management Journal, 21, 1105–1121) works on “dynamic capabilities” triggered a flood of debate and discussion on the topic. Unfortunately, the literature on dynamic capabilities has become mired in endless debates about definitions and has engaged in an elusive search for properties that make organizations adaptable. This article argues that the research program on dynamic capabilities needs to be reset around the fundamental strategic problem facing firms: how to identify and select capabilities that lead to competitive advantage. To this end, the article develops a framework that attempts to connect firms’ capability search strategies with their strategies in product markets. It frames firms’ capability search strategies as choices among different types of capability enhancing investments. The key distinguishing feature of capabilities in this framework is their degree of fungibility: capabilities span a continuum ranging from highly general-purpose (e.g., quality management) to highly market-specific (e.g., knowing how to manufacture an airplane wing). To illustrate the potential of the framework to shed new light on traditional strategy questions, the article applies the framework to explore some unexplained features of Penrosian diversification strategies. The article concludes by suggesting a research agenda for dynamic capabilities.

Free Dry Vibration of Low-Aspect-Ratio Cantilever Wing: SemiAnalytical and Numerical Analysis With Experimental Verification

The free vibration of a low-aspect cantilever wing is studied by semianalytical, numerical, and experimental means. The wing is modeled as a two-way tapered, hollow Kirchhoff's plate, with the chord-wise section as symmetrical NACA0018 aerofoil. The chord length and the thickness taper from root to tip, over the span. The semianalytical approach is based on Galerkin's method, which includes the modal superposition of two orthogonal beam modeshapes (free-free beam in chord-wise direction and cantilever beam in span-wise direction). The free vibration is also studied numerically using ANSYS. The results have been compared with an experimental study, performing the dry impact hammer test. A model scale wing has been constructed from a 3-mm-thick metal sheet, with a length-scale ratio of 1:10. Comparative studies have been done among the three methods. The feasibility of modeling a low-aspect-ratio wing as a plate has been investigated. 1. Introduction Lifting surfaces commonly occur in engineering structures: fans, steam and gas turbine blades, impeller blades, wind turbine blades, helicopter fans, airplane wings, marine propeller blades, marine rudders and skegs, and other control surfaces like hydrofoils and wings in high-speed marine crafts. The lifting surface is typically a cantilever, with one edge welded to the main structure (root), and the other end free (tip). The span-wise geometry is tapered, for greater strength at the root and lighter weight at the tip. The chord-wise cross section is an aerofoil, which acts as a lifting surface to the incoming flow at varying angles of attack. The aspect ratio of the lifting surface, i.e., the ratio of the span length to the mean chord length, may vary from 0.4 to 0.6 in a turbine blade to 12 to 15 in an airplane wing/wind turbine. This work focuses on a low-aspect-ratio lifting surface, whose usual span-to-chord ratio is 1.5–2.

New paradigm in advanced composite and nanocomposite design

Advanced composite materials are characterized by lightweight and unusually high stiffness, strength, modulus, etc. [ 1 , 2 ]. Their application field keeps on expanding as cheaper methods for synthesizing raw materials are found. Composite materials are now found in virtually all facets of applied materials [3] . Unlike a few decades ago when their application was limited to small parts; for example spoilers, failings, bonnets, etc., currently a new generation of airplane fuselage and wings are completely made of high-performance fiber reinforced composites [ 4 – 6 ]. The inherent high specific strength, low density, chemical and corrosion resistance [7] make them ideal for future applications. Typically, composite materials consist of a combination of two or more materials that are mixed with an aim of achieving a specific structural properties [8] . An effective composite should be able to optimize the properties of the individual components as one.

Electric Propulsion Concepts for an Inverted Joined Wing Airplane Demonstrator

One of the airplane design concepts that potentially allows for significantly increased efficiency, but has not yet been investigated thoroughly, is the inverted joined wing configuration, where the upper wing is positioned in front of the lower one. We performed wind tunnel and flight testing of a demonstrator of this concept, first by applying electrical propulsion to simplify wind tunnel testing, and then the same electrical-propulsion demonstrator performed several flights. As the chosen propulsion method proved to be too cumbersome for an intensive flight campaign and significant loss of battery performance was also observed, the electrical propulsion was then replaced by internal combustion propulsion in the second phase, involving longer-duration flight testing. Next we identified and analyzed two potentially beneficial modifications to the design tested: one involved shifting the center of gravity towards the aft, the other involved modifying the thrust vector position, both with the assumption that electric motors can be applied for propulsion. On this basis, the paper finishes with some conclusions concerning a new concept of electrical propulsion for an inverted joined wing design, combining two ideas: hybridization and distribution along the aft wing leading edge.

Airplane wing deformation and flight flutter detection method by using three-dimensional speckle image correlation technology.

Airplane wing deformation is an important element of aerodynamic characteristics, structure design, and fatigue analysis for aircraft manufacturing, as well as a main test content of certification regarding flutter for airplanes. This paper presents a novel real-time detection method for wing deformation and flight flutter detection by using three-dimensional speckle image correlation technology. Speckle patterns whose positions are determined through the vibration characteristic of the aircraft are coated on the wing; then the speckle patterns are imaged by CCD cameras which are mounted inside the aircraft cabin. In order to reduce the computation, a matching technique based on Geodetic Systems Incorporated coded points combined with the classical epipolar constraint is proposed, and a displacement vector map for the aircraft wing can be obtained through comparing the coordinates of speckle points before and after deformation. Finally, verification experiments containing static and dynamic tests by using an aircraft wing model demonstrate the accuracy and effectiveness of the proposed method.

On the nonlinear dynamics of shell structures: Combining a mixed finite element formulation and a robust integration scheme

In this work, we present an approach to analyze the nonlinear dynamics of shell structures, which combines a mixed finite element formulation and a robust integration scheme. The structure is spatially discretized with extensible-director-based solid-degenerate shells. The semi-discrete equations are temporally discretized with a momentum-preserving, energy-preserving/decaying method, which allows to mitigate the effects due to unresolved high-frequency content. Additionally, kinematic constraints are employed to render structural junctions. Finally, the method, which can be used to analyze blades of wind turbines or wings of airplanes effectively, is tested and its capabilities are illustrated by means of examples.

Discrete-Time Implementation and Experimental Validation of a Fractional Order PD Controller for Vibration Suppression in Airplane Wings

Vibrations in airplane wings have a negative impact on the quality and safety of a flight. For this reason, active vibration suppression techniques are of extreme importance. In this paper, a smart beam is used as a simulator for the airplane wings and a fractional order PD controller is designed for active vibration mitigation. To implement the ideal fractional order controller on the smart beam unit, its digital approximation is required. In this paper, a new continuous-to-discrete-time operator is used to obtain the discrete-time approximation of the ideal fractional order PD controller. The efficiency and flexibility, as well as some guidelines for using this new operator, are given. The numerical examples show that high accuracy of approximation is obtained and that the proposed method can be considered as a suitable solution for obtaining the digital approximation of fractional order controllers. The experimental results demonstrate that the designed controller can significantly improve the vibration suppression in smart beams.

The Parameters Optimization of Fusion Winglet Based on Orthogonal Experiment

The installation of winglet is an important method to reduce the induced drag, but if the winglet design is not good enough will increase weight and drag, and result in reducing the lift-drag ratio of the plane. With the small jets as the research object, referred the wing of longhorns to build basic airplane wing, with installation of fusion winglet. According to the 5 parameters of winglet established test models by the use of orthogonal test method, the test models were aerodynamic simulated and analyzed by Fluent, and studied the impact of 5 parameters on the lift-drag ratio. The results showed that: the setting angle has the greatest impact on the aerodynamic performance of winglet, and the model of winglet has better lift-drag characteristic which was optimized by orthogonal test, thus to provide theoretical basis for parametric design of winglet.