Browse Topic: Aircraft tails

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Aircraft Tail BumpersAIR1800B (Current)06/22/2021
This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.
A-5B Gears, Struts and Couplings Committee
Aircraft Tail BumpersAIR1800A (Historical)02/03/2021
This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.
A-5B Gears, Struts and Couplings Committee
Landing Gear Shock Absorption Testing of Civil AircraftARP5644A (Current)07/14/2020
The intent of this document is to provide recommended practices for conducting shock absorption testing of civil aircraft landing gear equipped with oleo-pneumatic shock absorbers. The primary focus is for Part 25 aircraft, but differences for Part 23, 27, and 29 aircraft are provided where appropriate.
A-5B Gears, Struts and Couplings Committee
Tool Wear Analysis on Drilling Process of Inconel 718 Superalloy2020-01-003403/10/2020
The Inconel 718 is an alloy based on nickel of high thermal and mechanical resistance, which allows its wide application in the aerospace industry, being generally implemented in aircraft tail cone and engine components. On the other hand, these features become a recurring problem when the machining of this material is performed. For example, in the drilling process of this superalloy, the cutting tools used exhibit excessive wear due to the high temperature and pressure at the cutting edge. However, there are numerous parameters that can influence the cutting tool life, and when analyzed and well defined, determine the types of modifications needed to enable less wear, and consequently an increase of its useful life in service. Given this context and knowing that the study of tool life in the Inconel 718 drilling process is extremely relevant in the aerospace sector, this paper presents a wear study in order to evaluate the behavior of different types of cutting tools used to drill
Barros, Pedro Cabegi, Barbosa, Gustavo Franco, Ventura, Carlos Eiji Hirata, Santos, Gustavo Roberto
Design of the Control Surfaces for an Aircraft Destined to the Competition SAE BRAZIL AERODESIGN2019-36-021401/13/2020
This work aims to present a methodology for the design of conventional control surfaces for light aircraft. Based on renowned aeronautical engineering references and standards, the theoretical framework presents the concepts of calculation for each flight phase particularity for each control surface in addition to a database with intervals of surfaces and their respective deflections of various aircraft. The methodology used takes into account the suggested steps for the aircraft design, where the dimensions are present in the preliminary design, according to the characteristics intended in the conceptual stage to develop conventional control surfaces aiming at the simplicity of design and the optimal response of control. The use of MATLAB and CFD software for data calculation and iterations are essential for the correct observance and evaluation of the obtained results. A comparative table and graphs will be elaborated for better visualization of the efficiency and behavior of each
Takano e Silva, Yoko Lucila, Kieling, Antonio Claudio, de Azevedo, Emile Diana Mendes, Vilaça, Neilson Luniere, Janzen, Renan Araújo, de Oliveira, Sanches Ismael
Numerical Modelling of Primary and Secondary Effects of SLD Impingement2019-01-200206/10/2019
A CFD simulation methodology for the inclusion of the post-impact trajectories of splashing/bouncing Supercooled Large Droplets (SLDs) and film detachment is introduced and validated. Several scenarios are tested to demonstrate how different parameters affect the simulations. Including re-injecting droplet flows due to splashing/bouncing and film detachment has a significant effect on the accuracy of the validations shown in the article. Validation results demonstrate very good agreement with the experimental data. This approach is then applied to a full-scale twin-engine turboprop to compute water impingement on the wings and the empennage. Since the performance characteristics of twin-engine commercial turboprops are such that they operate most efficiently at flight levels where SLD encounters may occur, the goal of this article is to establish a 3D computational methodology to eventually enable a complete study of the impact of FAR 25 Appendix O on the IPS requirements for this
Fouladi, Habibollah, Baruzzi, Guido S., Nilamdeen, Shezad, Ozcer, Isik
Landing Gear Shock Absorption Testing of Civil AircraftARP5644 (Historical)04/17/2019
The intent of this document is to provide recommended practices for conducting shock absorption testing of civil aircraft landing gear equipped with oleo-pneumatic shock absorbers. The primary focus is for Part 25 aircraft, but differences for Part 23, 27, and 29 aircraft are provided where appropriate.
A-5B Gears, Struts and Couplings Committee
Application of Extreme Value Theory to Crash Data Analysis2017-22-001111/13/2017
A parametric model obtained by fitting a set of data to a function generally uses a procedure such as maximum likelihood or least squares. In general this will generate the best estimate for the distribution of the data overall but will not necessarily generate a reasonable estimation for the tail of the distribution unless the function fitted resembles the underlying distribution function. A distribution function can represent an estimate that is significantly different from the actual tail data, while the bulk of the data is reasonably represented by the central part of the fitted distribution. Extreme value theory can be used to improve the predictive capabilities of the fitted function in the tail region. In this study the peak-over-threshold approach from the extreme value theory was utilized to show that it is possible to obtain a better fit of the tail of a distribution than the procedures that use the entire distribution only. Additional constraints, on the current use of the
Xu, Lan, Nusholtz, Guy
Aircraft Engine Exhaust Nozzle System for Jet Noise ReductionTBMG-2767710/01/2017
A system of nozzles and pylons that redistributes jet exhaust noise sources upstream to reduce jet noise has been developed. Certain aircraft configurations install the propulsion engines above the wing or tail surfaces, or above the fuselage, or in some cases above the structure that is a blend of the wing and body or hybrid wing body aircraft. In these aircraft configurations, reducing noise propagation to the community below is possible by using the aircraft as an acoustic shield for the sources associated with the engine. The more difficult engine noises to be shielded are from the jet exhaust because they are typically distributed downstream, the equivalent of several engine nozzle diameters. This innovation redistributes jet exhaust upstream to reduce noise.
777X Control Surface Assembly Using Advanced Robotic Automation2017-01-209209/19/2017
Fabrication and assembly of the majority of control surfaces for Boeing’s 777X airplane is completed at the Boeing Defense, Space and Security (BDS) site in St. Louis, Missouri. The former 777 airplane has been revamped to compete with affordability goals and contentious markets requiring cost-effective production technologies with high maturity and reliability. With tens of thousands of fasteners per shipset, the tasks of drilling, countersinking, hole inspection, and temporary fastener installation are automated. Additionally and wherever possible, blueprint fasteners are automatically installed. Initial production is supported by four (4) Electroimpact robotic systems embedded into a pulse-line production system requiring strategic processing and safeguarding solutions to manage several key layout, build and product flow constraints. Commonality amongst the robots was desired to allow each to effectively address any of the commodities which range from small fairings to very large
Mir, Ryan, DeVlieg, Russell
High Accuracy Assembly of Large Aircraft Components Using Coordinated Arm Robots2016-01-213309/27/2016
Aircraft manufacturers are seeking automated systems capable of positioning large structural components with a positional accuracy of ±0.25mm. Previous attempts at using coordinated arm robots for such applications have suffered from the use of low accuracy robots and minimal systems integration. Electroimpact has designed a system that leverages our patented Accurate Robot technology to create an extensively automated and comprehensively integrated process driven by the native airplane component geometry. The predominantly auto-generated programs are executed on a single Siemens CNC that controls two Electroimpact-enhanced Kuka 6 axis robots. This paper documents the system design including the specification, applicable technologies, descriptions of system components, and the comprehensive system integration. The first use of this system will be the accurate assembly of production empennage panels for the Boeing 777X, 787 and 777 airplanes.
Landau, Carl
Aerodynamic Analysis of the Elytron 2S Experimental Tiltwing Aircraft2016-01-200809/20/2016
The Elytron 2S is a prototype aircraft concept to allow VTOL capabilities together with fixed wing aircraft performance. It has a box wing design with a centrally mounted tilt-wing supporting two rotors. This paper explores the aerodynamic characteristics of the aircraft using computational fluid dynamics in hover and low speed forward flight, as well as analyzing the unique control system in place for hover. The results are then used to build an input set for NASA Design and Analysis if Rotorcraft software allowing trim and flight stability and control estimations to be made with SIMPLI-FLYD.
Grima, Alexander, Theodore, Colin, Garrow, Oliver, Lawrence, Ben, Persson, Linnea
The Integrated Minimum Drag Solution: New Wing Design Exponentially Increases Total Aircraft EfficiencyTBMG-2535809/01/2016
Innovators at NASA’s Armstrong Flight Research Center are experimenting with a new wing design that removes adverse yaw and dramatically increases aircraft efficiency by reducing drag. The technology has the potential to significantly increase total aircraft efficiency by optimizing overall aircraft configuration through the reduction in size or removal of the vertical tail, as well as the reduction of structural weight.
Aircraft Engine Exhaust Nozzle System for Jet Noise ReductionTBMG-2455505/01/2016
Conventional aircraft typically include propulsion engines that are under the wing or tail surfaces. Each propulsion engine system includes an engine housed in a nacelle with an inlet and a nozzle system. Primary component noise sources from the engine system include the noise associated with the fan, compressor, turbine, and combustor, and the noise associated with the high-velocity jet exhaust flow. There are many methods for reducing the various noise sources from the aircraft, including those noise sources from the engine system. One method includes the use of the aircraft itself as an acoustic shield for the noise sources associated with the engines. This approach requires a new configuration of aircraft with the engines installed on the upper surface of the wing or fuselage, or an aircraft that has a hybrid wing and fuselage. Of the engine noise sources, the jet exhaust is a particular challenge due to the fact that the noise sources are in the exhaust flow itself, and therefore
Technology Innovations in World War I Airplane Design2015-01-258109/15/2015
World War 1 began with the airplane as a frail, unarmed means of observing enemy troop movements and ended with the airplane as a powerful, much more evolved weapon of war. There were specialized roles for fighter, bomber and ground attack aircraft as well as newly developed aerial strategies and tactics for operational effectiveness. Many aircraft design technologies greatly matured during the war. Four will be the subject of this paper: Drag reduction, aircraft handling qualities, stability and control, airfoil design technology, and structures design technology. Propulsion and armament also matured greatly but are not discussed in the paper. The discussion of drag reduction will illustrate the innovations of the British on external wire bracing drag, the French on cowl design and the Germans on cantilevered wings and induced drag. Control surfaces and handling will show the invention of balanced controls, and the use of the equations of motion to design specific handling properties
Eberhardt, Scott
Pugh Analysis for Configuration Selection of a Hybrid Buoyant Aircraft2015-01-244609/15/2015
In comparison with traditional aircraft design, the configuration design phase of a hybrid buoyant aircraft is quite complex due to the augmentation of aerostatic and aerodynamic lift. The first step in assessing the optimal configuration for such aircraft is to approach the design in a number of different ways with different shapes of hull and diversed empennage arrangements. Concept selection methods like Pugh concept selection charts can assist to rank the population of different concepts of such aircraft. In the present work, an effort was done to explore the potential usage of Pugh's method in a comprehensive manner and to establish a basis for choosing a particular design concept. Driving factors of such design concepts were reviewed alongwith the selection of figure of merits, which were further evaluated by taking Megalifter as a reference with which all other configurations under consideration were compared. The initial set of concept generation was obtained on some initial
ul Haque, Anwar, Asrar, Waqar, Sulaeman, Erwin, Omar, Ashraf, Ali, Jaffar Syed Mohamed
Updating of an Unmanned Aerial Vehicle Finite Element Model using Experimental Data2015-01-246009/15/2015
In this paper the finite element model of an Unmanned Aerial Vehicle is updated by using experimental data coming from a standard ground vibration test in order to improve the numerical-experimental correlation. A sensitivity-based updating methodology that iteratively minimizes a residual vector, defined on the modal parameters (e.g. natural frequencies and mode shapes), is considered to identify the unknown values of the updating parameters. The structure under investigation is the Clarkson University Golden Eagle UAV. An initial numerical model of the structure is obtained by assembling the individual components previously updated which included wings, fuselage, horizontal tail, vertical tails and tail booms. As a result the identification procedure shifts its focus on the joints between UAV elements which could not be modeled accurately in earlier investigations.
Arras, Melissa, Coppotelli, Giuliano, Marzocca, Piergiovanni, Mezzapesa, Antonio Simone
Aerial Refueling Lights - Design CriteriaARP694C (Historical)07/04/2015
This ARP is intended to cover all external lights on the tanker and fixed wing receiver airplanes used to accomplish aerial refueling. This ARP describes lights used for two basic types of aerial refueling: The Probe and Drogue, and the Boom/Receptacle method.
A-20B Exterior Lighting Committee
A350XWB Icing Certification Overview2015-01-211106/15/2015
The intent of this paper is to provide a general overview of the main engineering and test activities conducted in order to support A350XWB Ice and Rain Protection Systems certification. Several means of compliance have been used to demonstrate compliance with applicable Certification Basis (CS 25 at Amendment 8 + CS 25.795 at Amendment 9, FAR 25 up to Amendment 129) and Environmental protection requirements. The EASA Type Certificate for the A350XWB was received the 30th September 2014 after 7 years of development and verification that the design performs as required, with five A350XWB test aircraft accumulating more than 2600 flight test hours and over 600 flights. The flight tests were performed in dry air and measured natural icing conditions to demonstrate the performance of all ice and rain protection systems and to support the compliance demonstration with CS 25.1419 and CS25.21g. Prior to the flight test campaign, extensive engineering analyses, laboratory tests and system
Toulouse, Marie-Laure, Lewis, Richard
Researchers Develop Multiphysics Model for Electro-Thermal Analysis of UAVTBMG-2118612/01/2014
Vives College University and Kulab (KU Leuven University campus Ostend) in Belgium are undertaking an aeronautical research program for the development of a new UAV aimed at performing scientific missions along the Belgian coastline above the North Sea. The main performance requirement of the UAV, dubbed Litus, is to be electrically powered with a range of 160 km and a payload up to 5 kg.
Optimization of Assembly Processes by Heated Air Technology2013-01-213309/17/2013
In today's assembly of large complex Carbon Fiber Reinforced Plastics (CFRP) components, e.g. vertical tail planes (VTP) of modern passenger aircrafts, liquid resin-based materials are used for several applications. Commonly, liquid resin-based materials are used to close gaps between the CFRP single parts during assembly (shimming) or to smoothen outer surfaces to fulfill aerodynamic requirements (aerodynamic sealing). Curing times of standard resin-based materials vary between eight to twelve hours at room temperature under normal shopfloor conditions regarding air humidity. In running aircraft production such long curing times are definitely waste in the sense of lead time. By heating these resin-based materials the common curing time can drastically be reduced down to two hours. By using heated air - instead of e.g. heating lamps - the curing process can reliably be controlled, without any risk of overheating and destroying the sealant or shim material. Both, the heated air
Gessenharter, Alexander, Van Koppen, Bjorn, Graf Bethusy-Huc, Marc-Philipp
A De-Spin and Wings-Leveling Controller for a 40 mm Hybrid Projectile2013-01-226209/17/2013
A Hybrid Projectile (HP) is a round that transforms into a UAV after being launched. Some HP's are fired from a rifled barrel and must be de-spun and wings-level for lifting surfaces to be deployed. Control surfaces and controllers for de-spinning and wings-leveling were required for initial design of an HP 40 mm. Wings, used as lifting surfaces after transformation, need to be very close to level with the ground when deployed. First, the tail surface area needed to de-spin a 40 mm HP was examined analytically and simulated. Next, a controller was developed to maintain a steady de-spin rate and to roll-level the projectile in preparation of wing deployment. The controller was split into two pieces, one to control de-spin, and the other for roll-leveling the projectile. An adaptable transition point for switching controllers was identified analytically and then adjusted by using simulations. The initial roll position may never be the same due to the round being inserted into its launch
Wilhelm, Jay, Close, Joesph, Huebsch, Wade, Gautam, Mridul
Airbus AI-PX7 CROR Design Features and Aerodynamics2013-01-224509/17/2013
The renewed interest in the fuel efficient and low CO2 emission CROR (contra-rotating open rotor) propulsion system for future commercial aircrafts has recently led to a series of isolated and installed CROR wind tunnel test campaigns performed in close collaboration between Airbus and the engine manufacturers. These tests aim at better understanding the potentials and limitations of the CROR configuration, as well as at generating reference data for the development and calibration of numerical tools for both industry and research centers. One of these tested CROR concepts is the AI-PX7 CROR propeller designed by Airbus. In this context, this paper presents multidisciplinary design features of modern high-speed contra-rotating propellers for commercial aircrafts. The influence of main CROR design parameters like blade number, propeller tip speed, rotor diameter, etc. on the propeller aerodynamics, acoustics and structures is described. Moreover, CROR blade shapes aerodynamic, acoustic
Negulescu, Camil A.
Application of Synthetic Jets to Enhance the Performance of a Vertical Tail2013-01-228409/17/2013
The performance enhancement of a vertical tail provided by aerodynamic flow control could allow for the size of the tail to be reduced while maintaining similar control authority. Decreasing tail size would create a reduction in weight, drag, and fuel costs of the airplane. The application of synthetic jet actuators on improving the performance of the vertical tail was investigated by conducting experiments on 1/9th and 1/19th scale wind tunnel models (relative to a Boeing 767 tail) at Reynolds numbers of 700,000 and 350,000, respectively. Finite-span synthetic jets were placed slightly upstream of the rudder hinge-line in an attempt to reduce or even eliminate the flow separation that commences over the rudder when it was deflected to high angles. Global force measurements on the 1/9th scale model showed that the flow control is capable of increasing side force by a maximum of 0.11 (19%). The momentum coefficient that created this change was relatively small (Cμ = 0.124%). Furthermore
Rathay, Nicholas, Boucher, Matthew, Amitay, Michael, Whalen, Edward
Improved Multibody Model of Flexible Wing2013-01-226509/17/2013
In the development of High Altitude Long Endurance (HALE) UAVs and their control the flexibility of the wing must be taken into account. The wing of this type of UAVs, usually made of highly flexible composite materials, has high aspect ratio with significant bending-torsional deformation during flight. The NASA Helios, as an example, has tragically shown that wing deformation coupled with control and power operation can cause serious problem in flight, instability can suddenly occur and can be quite difficult to foresee. In this paper the mathematical description of a flexible wing multibody model is presented. It is suitable to simulate the effect of both structural flexibility and flight dynamics and maneuvering on the wing deformation, and can be used to help developing control strategies for air vehicles with highly deformable wings. The paper will present simulation results for a typical HALE (High Altitude Long Endurance) wing with control surfaces and the effect of flexibility
Nagy, Andras, Gati, Balazs, Cestino, Enrico, Marzocca, Piergiovanni
Vertical Take-Off and Landing UAVTBMG-1532812/01/2012
The Air Force has announced that the MLB V-Bat Vertical Take-Off and Landing (VTOL) UAV from the MLB Company (Sunnyvale, CA) has been selected for a Phase II SBIR award. The military branch seeks a vehicle that has an 8-ft wingspan, 10-hour endurance, 55-lb gross take-off weight, and 70-mph cruise speed. The V-Bat’s combination of VTOL operational convenience with the safety of a shrouded fan and fixed-wing duration in a small UAV system will enable local situational awareness for UAV operations in confined areas. Last year, under a DARPA contract, MLB demonstrated precise emplacement of small payloads from the V-Bat, operating in hover mode under a vision-based control system.
Automated Work Sequencing in Constrained Areas Using Easily Portable and Optical Projection System2012-01-188509/10/2012
Projection systems are an optically projected 3-D sequence of operations that will guide an assembly technician through a set of complex operations with an intuitive instruction set that is portable and can be quickly set up in complex work areas. Example assembly applications include an aircraft baggage hold of a commercial jet, an inlet duct of a fighter jet, or inside a fuselage of a business jet. Clear, easy-to-follow instructions have been demonstrated to significantly improve assembly time and reduce rework. In many cases, instructions can be completely language independent allowing people of different nationalities to look at the same projection and work the same way without requiring additional instructions. This system provides increased uniformity of span time for given tasks between workers with a wide range of experience which improves scheduling. This paper highlights the uses and application of optically projected work instructions, particularly related to grip length
Richardson, Roger C.
Automated Horizontal Tail Plane Assembly Environment2012-01-189109/10/2012
Cost reduction efforts are driving aircraft manufactures to new assembly methods and strategic sourcing approaches. Global challenges, international competitors as well as increasing wages and salaries are leading to higher automation levels. ThyssenKrupp started researching new harmonized solutions for wing box, center wing box, vertical tail plane and horizontal tail plane that in 2007. The first step was to research the available technologies and to define how they can be used together to attend the new requirements of the aircraft industry. In 2009 ThyssenKrupp got the opportunity to apply the achieved results in a real application. One of the major challenges was to decide on the main premises for the assembly concept. Business case studies showed reasonable automation approaches; early investigations for health and safety topics showed up potential issues and detailed 3D concepts gave reliable results during the preliminary design review. The outcome is an automated environment
Brooksiek, Michael, Bunke, Joerg
Design Drivers of Energy-Efficient Transport Aircraft2011-01-249510/18/2011
The fuel energy consumption of subsonic air transportation is examined. The focus is on identification and quantification of fundamental engineering design tradeoffs which drive the design of subsonic tube and wing transport aircraft. The sensitivities of energy efficiency to recent and forecast technology developments are also examined.
Drela, Mark
Positioning System for the Aircraft Structural Assembly2011-01-263710/18/2011
This paper presents a new conception of a positioning technology concept for aircraft structural assembly, for instance the manufacturing of the fuselage sections from shell panels and floor grids, the alignment of the sections to build the fuselage, and the joining of wings and tail units to the fuselage. The positioning system features a modular, reconfigurable, and versatile solution for various aircraft dimensions and different applications. It provides the customer with a holistic solution that considers the positioning task taking into account the operation conditions and the environmental influences within the very same control unit. The positioning system consists of three main modules that communicate over a standardized interface: A large-scale metrology system for an accurate identification of the positions and orientation of the aircraft components, a mechanical system for the handling of these components and a control system. The latter is the core module of the
Mbarek, Taoufik, Meissner, Alexander, Biyiklioglu, Nihat
Design, Manufacturing, and Testing of a Research Unmanned Aerial Vehicle2011-01-272110/18/2011
This paper details the novel manufacturing processes for an experimental, all-composite, research UAV to be used by Clarkson University. Discussions will include an in depth report on the selection of materials, manufacturing methods, and the implementation and results of the fabrication procedures for the structural components along with the challenges of constructing an aircraft capable of meeting multiple FAA regulatory requirements.
Janas, Jordan, Marzocca, Piergiovanni, Valyou, Daniel, Abell, Matthew
Design Drivers of Energy-Efficient Transport Aircraft2011-01-2495-TEST-REC10/18/2011
The fuel energy consumption of subsonic air transportation is examined. The focus is on identification and quantification of fundamental engineering design tradeoffs which drive the design of subsonic tube and wing transport aircraft. The sensitivities of energy efficiency to recent and forecast technology developments are also examined.
Drela, Mark
Parallel Computing Applied to Three-Dimensional Droplet Trajectory Simulation in Lagrangian Approach2011-38-010606/13/2011
In the current study, continued efforts to improve a computational in-flight ice accretion prediction tool are introduced together with obtained results. The computational tool follows the usual procedure for computing ice shapes around three-dimensional bodies like wings, intakes, etc., i.e., flow-field calculation, droplet trajectory determination, droplet collection efficiencies calculation, convective heat transfer coefficient distribution computation and finally ice accretion rates determination using the Extended Messinger Method. Finally, integration of ice accretion rates over time yields the ice shapes and the final geometry. The emphasis in this study is on parallel computation of the droplet trajectories using the Langrangian approach. Since almost the entire computational time is used by the calculation of droplet trajectories in the developed computational tool, parallel computation allows fast and accurate analyses to be performed in a fraction of the time required for
Serkan, Ozgen, Erhan, Tarhan, Murat, Canibek
Analysis of Nozzle Jet Plume Effects on Sonic Boom SignatureTBMG-871711/01/2010
An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS
Aircraft Wing Flutter: An Applied Approach2010-36-051310/17/2010
In the last decades, the evolution of aircraft design has been influenced so much by aeroelasticity, and in particular, flutter. Flutter is a characteristic aircraft phenomenon of external excited vibrations, working on the resonance gap, which involves the structural airplane elements and if it was not reported can be the source of critical failures of wings or control surfaces. The present paper will give a general vision about flutter phenomenon in airplanes wings, specifically on planes of the aero design, which ones usually disregards this kind of study. However, this study includes an approach to explain the materials and methods used to find the results. Using data from aero design planes its possible presents how a mechanical engineer can use considerations of flutter to the project and analysis. With support of accelerometers the modal frequency of wing can be finding and it supplies data and graphs to justify values to maximum speed recommend and frequencies band that should
Dal'Carobo, Bruno, Fensterseifer, Ricardo
Solution for Automated Drilling and Lockbolt Installation in Carbon Fiber Structures2009-01-321411/10/2009
Manual drilling and Lockbolt installation in carbon fiber structures is a labor intensive process. To reduce man hour requirements while concurrently improving throughput and process quality levels BROETJE-Automation developed a gantry positioning system with high performance multi-function end effectors for this application. This paper presents a unique solution featuring fully automated drilling and Lockbolt installation (inclusive of automated collar installation) for the vertical tail plane (vertical stabilizer) of large commercial aircraft. A flexible and reconfigurable assembly jig facilitates high access of the end effectors and increases the equipment efficiency. The described system fulfils the demand for affordable yet flexible precision manufacturing with the capacity to handle different aircraft model panels within the work envelope.
Schwarze, Konrad, Mehlenhoff, Torsten
Design and Experimental Investigation of a Small UAV2009-01-316611/10/2009
In this paper two different tools have been applied to the problem of designing a small UAV. With these tools a parametric study of wing configuration and sizing was performed. The focus of this study was to optimize range and endurance of the UAV during a particular flight mission. The two numerical analysis tools applied to the UAV wing design were developed for widely different analysis problems. The first tool, the aircraft DATCOM was developed for the preliminary design analysis of manned aircraft and will be used to perform parametric modeling and geometry optimization. The Projectile Rocket Ordinance Design and Analysis System (PRODAS®) software was developed for ballistic projectiles and will be used for 6 DOF fixed plane trajectory simulation of the developed UAV concepts. While the scale of the UAV selected does not match well with the DATCOM software, the mission requirements and analysis format of the software is advantageous. Conversely, the scale of the problem matches
Coffin, P., Ahmadi, G., Jha, R., Marzocca, P., Su, W.-J., Manole, L.
Structural and Manufacturing Considerations for a Research Unmanned Aerial Vehicle2009-01-319611/10/2009
This paper discusses the various factors that were addressed in the planning process for the design and construction of an unmanned aerial vehicle (UAV) destined for use as a multirole research aircraft for Clarkson University. Details related to mission requirements, cost, construction materials, manufacturing methods, and regulatory requirements will be discussed. The resulting airframe, structure, manufacturing, and control system plan of action will be laid out. An overview of anticipated FAA regulations will be presented, and the need to design for conformity to said regulations addressed. Emphasis will be placed on design and manufacturing decisions relating to the extensive use of composite materials throughout the aircraft.
Valyou, Daniel, Dhaniyala, Suresh, Marzocca, Pier, Hopke, Phil
Aeroelastic Design of a Joined-Wing UAV2009-01-315011/10/2009
Aim of this study is the development of an integrated methodology able to support the structural design of an UAV demonstrator, having a joined-wing configuration and a high structural flexibility. HAPD (High Altitude Performance Demonstrator) is an UAV multi-mission, very light vehicle under development at CIRA, the Italian Aerospace Research Centre. HAPD structure is redundant as regards constraints, so the internal forces depend upon the stiffness distribution. In addition the evaluation of flight loads has to be performed without neglecting the flexibility of the structure. Because of the extreme unconventionality of the configuration the design of the primary structures has been widely affected by aeroelastic analyses. The final output of such a methodology (fully developed in-house) consists of all primary structures stiffness distributions (fuselage, wings and vertical tail unit) compatibly with the absence of any aeroelastic instability and structural failure under operative
Di Palma, L., Paletta, N., Pecora, M.
Traveling Column Machines for Automated Drilling and Fastening Operations on Different Aircraft Structural Components2008-01-228309/16/2008
The demand of fulfilling the increasing requirements to shorten development lead times force suppliers to enhance modularity and flexible applicability of their machinery component portfolio. The presented examples show how basically similar machinery components, i.e. traveling column systems, can be applied for significantly different types of applications in the aircraft industry. Application examples are shown for drilling and installation of two-piece and blind rivet fasteners on box-type and barrel-type aircraft structures at Airbus Deutschland. It is shown how the basic drilling/riveting system is integrated into assembly stations and assembly lines and how it adapts to the varying operational requirements of A380 and A400M.
Soehner, Christian, Mayländer, Holger
Correlation of Hand Book Method Results with Wind Tunnel Data for a Subsonic UAV Design2008-01-223308/19/2008
In the preliminary design phase of an aircraft, handbook methods are used to size the aircraft and to predict its aerodynamic characteristics and flight performances. For a new twin-boom pusher UAV a systematic comparison of theoretical predictions and wind tunnel test data is performed. It is shown that although performance and stability parameters are generally well predicted important deviations can occur if the specific airplane configuration is not taken into account in a sufficiently accurate manner. This is illustrated using results from pitching moment estimates for different tail configurations.
von Bergen, Stefan, Müller, Jürg
Aerodynamic Comparison of Tilt-Rotor, -Wing and -Body Concept for Multi Task MAVs2008-01-227508/19/2008
Multi task Micro Air Vehicles (MAVs) have been interested in last few years. VTOL and hovering capacities are required in case of flying in very confined zone and to enter into the building. In this paper, the VTOL concepts including tilt-wing, tilt-body, and tilt rotor had been studied. Analytical study and wind tunnel test have been done to compare different configurations by using the same power system. Since MAVs have been limited by size, the result concludes that tilt-body concept seems to be most appropriate for MAV application.
Thipyopas, Chinnapat
Flipperons for Improved Aerodynamic PerformanceTBMG-279105/01/2008
Lightweight, piezoelectrically actuated bending flight-control surfaces have shown promise as means of actively controlling airflows to improve the performances of transport airplanes. These bending flight-control surfaces are called “flipperons” because they look somewhat like small ailerons, but, unlike ailerons, are operated in an oscillatory mode reminiscent of the actions of biological flippers.
Generic Miniature Airplane for Research and DevelopmentTBMG-475312/01/2007
The Air Force Research Laboratory has promulgated the geometrical design of a miniature airplane denoted the Generic Micro Aerial Vehicle (GENMAV). This design is intended to serve as a baseline for analyses of geometrical designs of other micro aerial vehicles (MAVs). As such, the GENMAV design is meant to be distributed openly among organizations engaged in research and development pertaining to MAVs. The need for the GENMAV or a similar standard of comparison has become more acute in recent years because of the increasing interest in the use of MAVs [a subset of uninhabited aerial vehicles (UAVs)] for diverse purposes, especially in military, law-enforcement, and rescue activities.
Icing Analysis of the NASA S3 Icing Research Aircraft Using LEWICE3D Version 22007-01-332409/24/2007
Results of an icing analysis of the NASA S3 Icing Research Aircraft will be presented along with the latest improvements to the LEWICE3D ice accretion program. The icing results include collection efficiency and ice shape calculations for the S3. Recent improvements to the roughness and ice density models, performance and accuracy of the overall collection efficiency algorithm, and to the user interface for the LEWICE3D program will be discussed.
Bidwell, Colin
Development of a Shed-Ice Trajectory Simulation in FENSAP-ICE2007-01-336009/24/2007
A numerical approach to the trajectory simulation of break-up ice in the in-flight icing code FENSAP-ICE is investigated. At each time step, the displacement and rotation of the moving domains is computed from a 6-DOFs analysis of the forces and moments. The moving domains are amalgamated into the fixed background mesh by a hole-cutting and stitching algorithm, producing a continuous unstructured hybrid mesh, eliminating interpolation between domains and ensuring that the fluxes are fully conserved across the entire mesh. To maintain good load balancing on parallel computers, the finite element CFD flow solver uses an efficient parallel iterative matrix solver and domain decomposition to partition the computational domain into equal-sized subdomains. Test cases used to validate and demonstrate the features of the computational algorithm are shown.
Baruzzi, Guido S., Lagacé, Patrick, Aubé, Martin S., Habashi, Wagdi G.
Aerodynamic Fidelity of Ice Accretion Simulation on a Subscale Model2007-01-328509/24/2007
This paper presents the results of a study designed to determine the level of fidelity required to accurately reproduce the performance effects of ice accretion on airfoils. Castings of streamwise and spanwise-ridge ice accretions were obtained from tests in an icing wind tunnel. The streamwise-ice accretion was characterized by a smooth conformal shape on the leading edge followed by rime feathers downstream. For the spanwise-ridge ice accretion the leading edge of the airfoil was smooth. There was an upper surface ridge at x/c = 0.10 and a lower surface ridge at x/c = 0.17. The high-fidelity casting simulations were attached to the leading edge of a subscale (457.2-mm (18-inch) chord) NACA 23012 model and aerodynamic performance testing was performed at a Reynolds number of 1.8×106 and a Mach number of 0.18. Lower-fidelity simulations were developed for each ice accretion to determine the fidelity required to match the performance of the airfoil with castings. For the streamwise ice
Broeren, Andy P., Busch, Greg T., Bragg, Michael B.
Method to evaluate takeoff distance for nose-gear light aircrafts2006-01-275311/21/2006
The process of takeoff distance estimation for nose-gear light aircrafts involves several parameters such as aircraft total weight, runway type, engine power, aircraft geometry, aircraft aerodynamic characteristics, among others. This work demonstrates a method to evaluate the takeoff distance through monitoring the force system acting on the aircraft during the takeoff run. The numerical approach considers discrete time steps. Details of the implementation and limitations of the method are presented. Through this procedure it is possible to easily vary the basic aircraft configuration, allowing fast analysis of many different configurations to select the best for a particular performance.
Coelho, Thiago Campos Gondim Martins, Cateb, André Carvalho, Vieira, Bernardo Augusto de Oliveira, Minette, Ricardo Soares, de Sousa, Rodrigo Sorbilli Cardoso, Cimini, Carlos Alberto
Simulation and Visualization Environment for Nonlinear Helicopter Flight Dynamics2006-01-242508/30/2006
The Analytic 6 D.O.F. dynamic model of a helicopter is developed for 3D computer generated imagery simulator. Analytic expressions for the forces and moments on the various helicopter components are derived. By using the forces and moments equilibrium, helicopter trim point is determined using Newton's method of solving the nonlinear set of trim equations. The equations of motion for the fuselage six degree of freedom are assembled by applying Newton's law of motion relating the applied forces and moments to the resulting translational and rotational acceleration. Visual C++ programming software, utilized as a platform will interact to MATLAB Aircraft Instrument ActiveX and 3DSTATE for graphical 3D rendering process.
Nasiri, M., Rezazade, M.
Destructive Evaluation of Aging General Aviation Airplanes2006-01-240908/30/2006
Due to current economic conditions, aircraft companies of today are experiencing an increasing need for their fleets to maintain safe operation beyond their original design life. The result is a growing percentage of aging aircraft that must maintain their airworthiness by utilizing standard methods of inspection and repair. In order to determine if potential continuing airworthiness problems exist for the general aviation fleet as a function of the aging process, the Federal Aviation Administration (FAA) established a research program at the National Institute for Aviation Research, Wichita State University, to conduct destructive evaluations of aged airplanes. The intent of the program is to provide insight into the condition of a typical aged airplane and to see if a correlation exists between its maintenance history and current condition from a safety of flight perspective. To date, three airplanes, used in commuter service - a 1969 Cessna 402A, a 1979 Cessna 402C, and a 1975 Piper
Laubach, Melinda, Cope, Dale
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