Aeronautical Engineering

The aerodynamic performance of an aircraft can be enhanced by incorporating wingtip devices, or winglets, which primarily reduce lift-induced drag created by wingtip vortices. This study outlines an optimization procedure for implementing winglets on a Class I fixed-wing mini-UAV to maximize aerodynamic efficiency and performance. After the Conceptual and Preliminary design phases, a baseline UAV was developed without winglets, adhering to specific layout constraints (e.g., wingspan, length). Various winglet designs-plate and blended types with differing heights, cant angles, and sweep angles-were then created and assessed. A Computational Fluid Dynamics (CFD) analysis was conducted to evaluate the flow around both the winglet-free UAV and configurations with each winglet design. The simulations employed Reynolds-Averaged Navier-Stokes (RANS) equations coupled with the Spalart-Allmaras turbulence model, targeting the optimal winglet configuration for enhanced aerodynamic characteristics during cruise. Charts of lift, drag, pitching moment coefficients, and lift-to-drag ratios are presented, alongside flow contours illustrating vortex characteristics for both baseline and optimized configurations. Additionally, dynamic stability analyses examined how winglets impact the UAV's stability and control. The results demonstrated a significant improvement in aerodynamic coefficients (C Lmax , L/D max , C La , C ma), leading to an increase in both range and endurance.

A predominantly experimental investigation into the nature of transonic flow within an aerodynamic corner is treated. The work focuses on exploring the shock-induced separation that can occur due to the corner. Effects of dihedral angle, and sharp and filleted 90 o corners were studied on a RAE2822 profile wing. Tests were conducted in a shock tube operating as a short-duration transonic tunnel, using oil-film surface flow visualisation techniques. The experimental results are compared to numerical simulation studies. The CFD results correlate well with the experiments. It is shown that a fillet radius disperses the region of separated and reversed flow outwardly from the centre of the corner. Increasing the dihedral angle of the corner significantly delays and weakens the separated region.

La intermitencia ocurre cuando una senal alterna explosiones caoticas con periodos de cuasi regularidad llamados fases laminares. Se ha estudiado que el numero de explosiones caoticas se incrementa en funcion de la variacion de un parametro externo, entonces el fenomeno de intermitencia es un camino continuo de movimientos regulares a caoticos. Entre las aplicaciones mas importantes en mecanica de los fluidos, donde el fenomeno de intermitencia se presenta, se encuentra la transicion a la turbulencia y la turbulencia misma. La evaluacion correcta de este fenomeno contribuye a una mejor prediccion de estos temas. En este trabajo se emplea una nueva teoria desarrollada para estudiar intermitencia en mapas (E. del Rio y S. Elaskar, Int. J. Bifurcation and Chaos, 20(4):1185–1191 (2010), S. Elaskar et al., Physica A, 390:2759–2768 (2011)) para ser aplicada a un sistema dinamico continuo que resulta del truncamiento a tres ondas de la ecuacion derivada no lineal de Schrodinger (DNLS), la ...

 The influence of topography on wind pressures acting on structures has been of interest to the civil engineering community for some time; however, because of the complexity of the problem, only few cases have been solved. The evaluation of pressures in tanks located in hills is one of those complex problems and has not been addressed in the literature. This paper presents a computational fluid dynamics simulation of the problem, in which the domain including the hill and the tank is discretized using finite elements. The results show that the actual location of the tank with respect to a hill has a significant influence on the pressures, so that tanks located at the top of a hill undergo severe increases in pressure coefficients and also changes in pressure distributions around the tank. Keywords CFD, finite elements, tanks, topographic effects, wind pressures

Thispaper attempts to provide a systematic design procedure for the concept model of a pesticide spraying UAV. Avionics selection is explained along withCAD modelling using CATIA V5 and analysis using ANSYS 18.1 software. Finite element method is used to perform static structuraland modal analysis on the frame. Results are obtained for total deformation and equivalent stress. The UAV is to be 3D printed with ABS filament. The payload for the concept model is 1.5kg and diagonal dimension is 678 mm. Keywords— UAV, FEM, FEA, CATIA, ANSYS, ABS, Quadcopter

elaborado con fines académicos; en el mismo se reflejó información de-identificada y los datos del proceso en el cual se aplicó la metodología DMAIC fueron presentados de manera tal que permita preservarse la confidencialidad de los mismos. El presente trabajo está destinado únicamente a la lectura por parte del personal docente afectado a la corrección del mismo y queda prohibida su reproducción total o parcial y/o distribución a terceros. Del mismo modo, queda prohibida su exposición ante alumnos de cualquier carrera de la Universidad del Salvador como así también, queda prohibida su distribución a otras instituciones, sin el consentimiento previo y formal de la autora.

Avoidance of near misses or collisions is required for almost all satellites on orbit, but it is of particular interest for manned missions and spacecraft at densely populated regions. In order to avoid these possible collisions, it is needed to determine a possible conjunction and its associated uncertainty. Two main constraints must be taken into account when a tool to forecast the collision risk of an object is being developed: the high number of objects in space and the accuracy of the catalogued object data. The number of objects on Earth orbit makes impossible to propagate all the catalogued objects, thus filtering and parallel processing techniques are presented. The accuracy of the catalogued object data and the propagation of the error over the time identify a position ellipsoid of error, whose behaviour has an important influence on some parameters on the filtering techniques and the way the collision probability is computed. Some collision probability methods are presented.

Energy harvesting from aeroelastic instabilities is a recent solution to provide alternative power generators. In particular, the two-degrees-of-freedom classical flutter involves relevant amounts of energy that can be extracted to generate electricity through a suitable conversion apparatus. To provide effective generators, stable steady-state oscillations after the instability onset are required. The problem involves several parameters and an important open issue is the basic post-critical dynamics of flutter on which the research is evolving nowadays. In the present study, the parametric space is investigated in order to understand its main features. The critical condition and the role of some parameters on the power efficiency were preliminary explored with linear analyses. Wind tunnel tests were conducted to experimentally validate the numerical results and to focus the investigations on the system behavior after the instability threshold. The energy generation is simulated thr...

The post-critical flutter regime is still an open issue, despite the interest for its applications in the field of energy harvesting, where the knowledge of the self-sustained motion at large amplitudes is of crucial importance. In the paper, the experimental approach has been followed to investigate this issue. The role of some governing parameters, mainly the mass centre position and the damping level in the translational degree of freedom, were investigated through wind tunnel tests, evaluating their effects on the critical condition and subsequent oscillatory regime. Linear analyses supported the identification of the instability threshold. Downstream mass eccentricity of about 0.05 times the section chord significantly anticipated the critical onset velocity and modified the motion characteristics, in terms of ratio between translational and rotation amplitudes and their phase difference. External damping was introduced, up to a ratio-to-critical value of 18%, and the consequen...

Aos meus irmãos Leonardo e Guilherme, e à pequena Débora, nossa amada irmã. Se eu puder, de alguma forma através dos meus esforços, inspirá-los a sempre seguir em frente com honestidade, bondade e justiça, terei alcançado um de meus grandes objetivos de vida. ão se preocupe em ser um gênio e não se preocupe se não for inteligente. Confie mais no trabalho duro, na perseverança e na determinação. O melhor lema para uma longa marcha é " ão resmungue. Agüente". Você tem o futuro nas mãos. unca duvide disso. ão se gabe. O menino que se gaba, assim como o homem que se gaba, pouco mais pode fazer. É um zé-ninguém que anuncia sua própria mercadoria barata. A lata vazia é a que faz mais barulho. Seja honesto. Seja leal. Seja bondoso. Lembre-se que a coisa mais difícil de conseguir é a faculdade de ser altruísta. Como qualidade, é um dos mais belos atributos da masculinidade. Ame o mar, a sonoridade da praia, os prados amplos. Mantenha-se limpo de corpo e mente.

This paper documents an attempt to measure unsteady l oads during performance tests of a generic scramjet engine model with high-frequency pressure gages recessed i nto the i nterior wall to reduce thermal flux to the gage diaphragm. The gages were installed i n existing calorimeter ports. The model was designed by the Johns Hopkins Applied Physics Laboratories and tested in the Combustion-Heated

A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mission and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would use the same correction coefficient and that the aft wing would be lighter than the fore wing on the medium range box wing aircraft because of reduced sweep. As part of the methodology, a computational study was performed to analyze different wing/tip fin fixities using a statically loaded idealized box wing configuration. The analyses determined the best joint fixity by comparing the stress distributions in finite element torsion box models in addition to aerodynamic requirements. The analyses indicates that th...

Vorticity forces on a delta wing from the perspective of a force element theory CHENG-TA HSIEH, JIAN-JHIH LEE, CHIEN C. CHANG, CHIN-CHOU CHU, National Taiwan University -In this study, we consider various force contributions to an impulsively started delta wing from the perspective of a force element theory. A wing plate of aspect ratio AR is placed at the angle of attack (α) to the incident stream. We consider 3 aspect ratios of the delta wing: AR=1, 2, 4 and 3 angles of attack α=15 • , 30 • and 45 • , while the Reynolds number Re is set to be the fixed 300. The force element theory enables us to examine forces exerted on the a delta wing credited to the individual flow structures, such as the leading-edge vortex (LEV), trailing edge vortex (TEV), as well as the contribution from the surface vorticity. It is widely known that flow over a delta wing is genuinely three-dimensional, and there is no two-dimensional analog. Here, we provide an insightful understanding of flow characteristics by relating the forces directly to the various sources of vorticity (wx, wy and wz) on or near the wing plate. The relative importance of the various vorticity contributions to the hydrodynamic forces is analyzed in terms of the aspect ratio and angle of attack.

Aerodynamics and Performance Estimation Toolset is a collection of four software programs for rapidly estimating the preliminary design performance of aerospace vehicles represented by doing simplified calculations based on ballistic trajectories, the ideal rocket equation, and supersonic wedges through standard atmosphere. The program consists of a set of Microsoft Excel worksheet subprograms. The input and output data are presented in a user-friendly format, and calculations are performed rapidly enough that the user can iterate among different trajectories and/or shapes to perform "what-if" studies. Estimates that can be computed by these programs include: 1. Ballistic trajectories as a function of departure angles, initial velocities, initial positions, and target altitudes; assuming point masses and no atmosphere. The program plots the trajectory in two-dimensions and outputs the position, pitch, and velocity along the trajectory. 2. The "Rocket Equation" pr...

El tren de aterrizaje es el mecanismo que hace la conexión entre la nave y el suelo (o el agua, según sea el caso). Este proyecto se centra en el diseño del tren de aterrizaje con material compuesto. El material compuesto a utilizar en este proyecto, es un acero AISI-4340 con un arreglo de inclusiones. Este se trabajó con la teoría de inclusiones de Eshelby [1], la cual explica la manera en que actúa un cuerpo compuesto de inclusiones, que es una matriz embebida en otra matriz. Se busca entonces, con este estudio, crear un material anisótropo, para elegir la dirección de las líneas de esfuerzo, en pro de ofrecer una mejor relación rigidez-peso en la dirección de la carga. Se utiliza la herramienta de Análisis de Elemento Finito para realizar el estudio. Se hace un análisis estático y un análisis modal para observar su comportamiento.

Este proyecto tiene el proposito de desarrollar el diseno de un avion a control remoto tipo competencia Aerodesign. Por lo tanto se establecieron varios objetivos como: el diseno del perfil alar, calcular el area de sustentacion, seleccionar el diseno de la estructura de alas y fuselaje, disenar el de tren de aterrizaje y disenar el sistema de dinamica y control. Basados en estos objetivos se realizo el diseno final del avion a control remoto. El proceso de diseno fue basado en la reglas que publica la Sociedad de Ingenieros Automotrices de Estados Unidos (SAE). Esta reglas establecen lo requerimientos minimos del diseno con el objetivo de cumplir la capacidad de el avion de despegue y aterrizaje, asi como poder levantar carga efectiva de 25 lbs. Por otra parte el diseno fue enfocado a obtener un avion capaz de cumplir los requerimientos de diseno de SAE Aerodesign y un bajo costo. En resumen el proyecto fue terminado en tiempo y objetivos planteados al inicio del proyecto se cumpli...

El tren de aterrizaje es el mecanismo que hace la conexion entre la nave y el suelo (o el agua, segun sea el caso). Este proyecto se centra en el diseno del tren de aterrizaje con material compuesto. El material compuesto a utilizar en este proyecto, es un acero AISI-4340 con un arreglo de inclusiones. Este se trabajo con la teoria de inclusiones de Eshelby [1], la cual explica la manera en que actua un cuerpo compuesto de inclusiones, que es una matriz embebida en otra matriz. Se busca entonces, con este estudio, crear un material anisotropo, para elegir la direccion de las lineas de esfuerzo, en pro de ofrecer una mejor relacion rigidez-peso en la direccion de la carga. Se utiliza la herramienta de Analisis de Elemento Finito para realizar el estudio. Se hace un analisis estatico y un analisis modal para observar su comportamiento. Se selecciono una cavidad con geometria elipsoide. Se diseno con una sola elipsoide, pues resulto ser mas eficiente que con otras configuraciones. La r...

Hole-flanging is a crucial operation in sheet metal forming technology, where the material around a prefabricated hole is deformed by a spherical, conical, or cylindrical punch to create a flanged hole wall. This study aims to determine the limiting hole-flanging coefficient of AA1050-O aluminum alloy sheet using the Cockroft-Latham ductile fracture criterion. Numerical simulations of the hole-flanging process using the Cockroft-Latham ductile fracture criterion were conducted to identify the limiting hole-flanging coefficient of AA1050-O aluminum alloy sheet. The limiting hole-flanging coefficient of the material was found to be 0.61 and was further verified through experiments. Additionally, the effects of the hole-flanging coefficient on the Cockroft-Latham damage value, minimum thickness, and height of the flanged hole wall were evaluated within the formability region of the material when the coefficient exceeded the limiting value. The findings from this study provide valuable insights for designing hole-flanging operations for AA1050-O aluminum alloy sheet.

Small wind turbines (SWTs) can generate sufficient electricity to meet the energy needs of developing countries. However, due to the airflow characteristics at low Reynolds numbers and associated issues, specific airfoil designs are crucial to define the blade geometry. In this study, the lift coefficient (CL), stall angle of attack (AoA), and lift-to-drag coefficient ratio (CL/CD) of S1048, S3021, and S5010 airfoils and then optimized shapes with various thickness-to-camber ratio percentages (t/c%) were analyzed using XFOIL software to optimize their suitability for SWT applications. The aerodynamic efficiency of the optimized airfoils in terms of CL, drag coefficient (CD), CL/ CD, and stall AoA was evaluated across Reynolds numbers ranging from 50,000 to 500,000. The findings revealed that these modified airfoils exhibited peak CL/ CD values surpassing those of their baseline airfoils for the Reynolds number range of 50,000-500,000. The magnitudes of these improvements varied for each airfoil and at different Reynolds numbers. Additionally, the geometric modifications in terms of t/c% applied to the S1048, S3021, and S5010 airfoils resulted in enhanced maximum CL and stall AoA across all analyzed Reynolds numbers. Keywords Airfoil • Low Reynolds numbers • Performance • Lift-to-drag • Optimization • Aerodynamics List of Symbols c Chord length (m) CL Lift coefficient (-) CL/CD Lift-to-drag coefficient ratio (-) CD Drag coefficient (-) FD Drag force (N) FL Lift force (N) L Length that characterizes the scale of the air l Airfoil span (m) U Air velocity (m s −1) B Hossein Seifi Davari

This paper exposes a simplified preliminary conceptual integrated method to design an aircraft wing in subsonic speeds up to Mach 0.85. The proposed approach is integrated, as it allows an early estimation of main aircraft aerodynamic features, namely the maximum lift-to-drag ratio and the total parasitic drag. First, the influence of the Lift and Load scatterings on the overall performance characteristics of the wing are discussed. It is established that the optimization is achieved by designing a wing geometry that yields elliptical lift and load distributions. Second, the reference trapezoidal wing is considered the base line geometry used to outline the wing shape layout. As such, the main geometrical parameters and governing relations for a trapezoidal wing are reviewed in details. Third, the integrated design method is introduced through an evocative flowchart that describes the wing design process, whose objectives are essentially the determination and the optimization of the different wing parameters, essentially: Wing Area, Sweep Angle, Aspect Ratio, Taper Ratio, Thickness and Twist. Furthermore, refined and assessed formulas identified from an exhaustive literature study and historical trends yielding accurate and logical estimation of each parameter described in the optimization flowchart are provided. Finally, the capability of the proposed method is investigated through two design examples for jet and propeller aircrafts. The obtained layouts are tested and verified through simulations using the NASA OpenVSP simulation software.

of the relative motions between formation flying space vehicles in orbit about the Earth and Mars. Formation flying is proposed for: cross calibration of science instruments on follow-on missions and new technology demonstrations, moving from large platforms to several smaller vehicles with distributed instrumentation (virtual platjorms) and spaceborne interferometry. In Mars orbit, a small constellation for in-situ navigation is being considered to enable automated operations and to reduce Earth based tracking requirements. To establish achievable control accuracies for these types of missions, dynamics in the orbit design space are examined thoroughly. Aspherical and third body gravity, atmospheric drag, and solar radiation pressure are the primary dynamic forces responsible for producing relative motions. High fidelity models of these forces are used to examine the relative motion characteristics of circular LEO and GEO orbits and circular low and synchronous Mars orbits.

Super alloys are metallic materials for service at high temperature, so one of their most important properties is high temperature creep resistance. Other crucial material properties are fatigue life, phase stability, as well as oxidation and corrosion resistance. A conventional metal may be failed in high temperature machining condition and has poor creep resistance, so materials for working at high temperature and which having also good creep resistance are a critical issue in manufacturing. this paper present a review about the Nibase super alloys, which working at high temperature and also having a good machining property and having good creep resistance.

Finite Element Analysis (FEA) has become a vital resource in the aerospace industry, allowing engineers to simulate and scrutinize intricate structural, thermal, and fluid dynamics issues with remarkable accuracy. This computational method helps predict stress distribution, deformation, vibration modes, and thermal characteristics in aerospace components like airframes, wings, engines, and landing gear under various operating conditions. By dividing complex structures into smaller, manageable finite elements, FEA offers astute judgments into performance, safety, and durability while minimizing the need for expensive physical prototypes and testing. In the aerospace field, FEA is essential for optimizing weight, enhancing fuel efficiency, ensuring compliance with strict safety regulations, and speeding up the design process.

The stochastic nature of Air Traffic Management arises mainly from uncertain operational events. This uncertainty may jeopardize the Central Flow Management Unit (CFMU) planning leading to safety problems and sub optimally used capacity. An absorption area is defined as one or several free slots in the planning so that the management of uncertainty is easier. Its aim is to compensate the aircraft uncertainty. The issue is to use the free slots in order to absorb uncertainty, and so not modify the initial planning. Finding the best configuration of the absorption areas corresponds to balancing optimally their size with the available capacity in order to absorb uncertainty and minimize "load loss" (unused capacity).

In the era of market and work-force globalization engineers need a solid understanding of the impact their products have locally as well as globally. This is why the US Accreditation Board for Engineering and Technology recently put a new spin on this requirement in engineering education. Specifically, outcome 3h of Engineering Criteria 2000 states that engineering graduates must have "the broad education to understand the impact of engineering solutions in a global / societal context". This outcome may be one of the most difficult to achieve since it requires not only a strong technical understanding but also an informed societal and historical perspective that is particularly difficult to achieve. This paper identifies some of the skills students need to be able to evaluate the impact of their solutions in a global / societal context as well as methods used by some universities to address this issue outside of technical engineering courses. The main focus of this paper is the introduction of course design elements that help students master these skills that can be incorporated into required and elective engineering courses. Examples are presented from a variety of thermal/fluid courses where these skills are taught in the Mechanical and Aerospace Engineering Department at San Jose State University.

Resumen-Similar al funcionamiento del Sistema de Posicionamiento Global (GPS), existen diversos sistemas desarrollados para la localización y el guiado de móviles en espacios interiores. En estos sistemas se estima la posición del móvil estableciendo una relación espacial, entre las balizas (satélites en GPS) y el móvil. Para lograr esto, comúnmente se utilizan técnicas de Trilateración Esférica (TE) o Hiperbólica (TH). En cualquier caso los buenos resultados de localización dependen de la correcta ubicación de las balizas, así como de la cantidad adecuada de ellas, con el fin de tener la cobertura deseada en el entorno de trabajo, costos bajos y precisión en las estimaciones de localización del móvil. En este trabajo se utilizó la metodología de optimización llamada DLS, con el fin de encontrar distribuciones optimizadas de balizas en sistemas que usan TE o TH. Con los resultados obtenidos aplicando cada técnica, se hace una comparación de distribuciones optimizadas de balizas entre sistemas que aplican TE y TH. Se distinguen distribuciones regulares de tripletas formando triángulos equiláteros y cuartetos en "Y" para TE y TH respectivamente, sin embargo la orientación de estos elementos base depende bastante de la forma del área a cubrir. Las soluciones obtenidas en TE usan alrededor de 40 % menos de balizas que con TH. Palabras clave-Búsqueda Tabú, búsqueda Local, optimización de cobertura, dilución de precisión, trilateración esférica e hiperbólica.

Energy savings and enhancement of mechanical properties in aluminum forgings, produced in 2000 series alloys, processed by rapid infrared (RI) radiant heating were investigated. Pilot-scale production with a hybrid infrared system indicates 50-90% energy savings relative to conventional production with convective furnace heating with a significant decrease in process cycle times. Rapid preheating prior to forging produced finer grain sizes in solutionized specimens than those in specimens preheated in a gas-fired convection furnace. The reduced grain size gives the forgings longer fatigue life when tested in the solutionized and aged condition. Specimens forged with RI-preheating showed stronger age hardening, verified by hardness and tensile tests, than those forged with conventional furnace preheating. RI processing potentially leads to energyefficient, low cost commercial production with improved mechanical properties.

The Black Nightmare Bombardier V.7.3 is an advanced hydrogen-powered unmanned aerial vehicle (UAV) integrating cutting-edge stealth, AI guidance, and vectoring aileron technology. With superior maneuverability, an extended operational range, and an innovative defensive missile system, this UAV redefines modern aerial combat capabilities.

Prognostics of large composite structures is a topic of increasing interest in the field of structural health monitoring for aerospace, civil, and mechanical systems. Along with recent advancements in real-time structural health data acquisition and processing for damage detection and characterization, model-based stochastic methods for life prediction are showing promising results in the literature. Among various model-based approaches, particle-filtering algorithms are particularly capable in coping with uncertainties associated with the process. These include uncertainties about information on the damage extent and the inherent uncertainties of the damage propagation process. Some efforts have shown successful applications of particle filtering-based frameworks for predicting the matrix crack evolution and structural stiffness degradation caused by repetitive fatigue loads. Effects of other damage modes such as delamination, however, are not incorporated in these works. It is wel...

This study investigated the stack drillability of unidirectional (UD) carbon fiber-reinforced thermoplastic matrix PAEK/CF composite and aluminum (AA7075) plate utilized in aerospace. The effects of cutting parameters on cutting forces during the drilling process of thermoplastic matrix composites and aluminum materials were experimentally analyzed. 3 different cutting speeds (55, 95, and 165 m/min) and feed rates (0.1, 0.2, and 0.3 mm/rev) were used in the experimental study to investigate the drilling performance of 3 different types of drills (Types A, B, and C) with rounded cutting edge and surface treatment of the same diameter. Drilling operations were carried out on a CNC Vertical Machining Center under dry-cutting conditions. For 3 different drill types, 3 different cutting speeds, and feed rate combinations, a total of 810 holes were drilled in a full factorial experimental design with 30 replicates for each combination. The damage on the hole surfaces on the drilled composite was identified with an optical microscope. The numerical data obtained in the composite testing laboratory and we were analyzed using Minitab® 21.1 statistical software and transformed into graphs. The most suitable drill type and cutting parameters were determined for the drillability of PAEK/CF composite with thermoplastic matrix and aluminum (AA7075) plates when stacked.

L'attuale filosofia di progetto per le strutture aeronautiche inizia a divenire troppo conservativa, soprattutto dopo l'introduzione di materiali più efficienti e avanzati strumenti di analisi. Per questo motivo il Progetto Europeo DAEDALOS si prefigge lo scopo di sviluppare nuovi competitivi metodi di progetto per la riduzione di peso strutturale, che potrebbe portare anche alla riduzione di emissioni degli aeroplani civili. L'obiettivo di questo lavoro di tesi, situata all'interno di questo progetto, è di determinare una base comparativa per quanto concerne i carichi dimensionanti dovuti alla turbolenza atmosferica (per il solo modello Discrete Gust Criterion), seguendo le tecniche di progetto correnti, al fine di valutare nuove metodologie. L'attività è focalizzata sulla generazione di modelli numerici strutturali e la definizione delle condizioni di carico dovute alla raffica atmosferica. I modelli ad elementi finiti degli impennaggi di un aereo civile (business jet) vengono definiti e utilizzati nel processo di riduzione; a questo scopo viene proposta una metodologia per ottenere le caratteristiche di rigidezza e massa equivalenti di un modello a trave e verificata con dei semplici modelli di trave. Successivamente il metodo di riduzione viene applicato agli impennaggi, generandone così i modelli a travi. Accanto alla filosofia di progetto attuale viene illustrata una soluzione alternativa, definita Upgraded Design Philosphy; non si tratta di un nuovo metodo, ma può essere la base per futuri sviluppi. Essa consiste nel condurre le analisi dinamiche direttamente su modelli strutturali ad elementi finiti di dettaglio o ibridi. Infine, le due procedure di progetto presentate sono applicate ai modelli del velivolo e confrontate in termini di risposta dinamica e livello di sforzo su componenti strutturali. I risultati hanno mostrato la validità della filosofia di progetto alternativa. Parole chiave: carichi di raffica, raffica discreta, processo di riduzione, filosofia di progetto, modello a travi, carichi dinamici

Contemporary projects requiring real time positions with especially cm accuracies have begun to employ Real Time Kinematic GPS (RTK GPS) technique for its speedy and productive nature. As in all types of GPS techniques, RTK GPS is also vulnerable to multipath errors. The purpose of this study is to investigate this source of error. This study tries to answer some questions such as how much multipath error causes real time positioning error, and in what kind of environment this error is the most effective. A background on multipath error is first given and the environment causing this effect is widely researched, and then a test that brings out the most multipath error is conducted. The findings are presented, and conclusions and suggestions are included for future researches.

This paper contain the content of basic review of an aircraft fuel system .This paper cover the various fuel system and fuel subsystem used in aircraft .Purpose of an aircraft fuel Sub system to monitors the fuel supply, its control, storage, drainage and also maintain stability of aircraft.. Basically the purpose of fuel system is to supply the fuel in all phase of including landing ,takeoff, Banking and sharp maneuvering fuel system should also supply the sufficient amount of neat and clean fuel at required pressure. Types of fuel system may vary in aircraft but all the aircraft keeps their own fuel system. The fuel system must be used keeping the centre of gravity to be stable in mind.

In contemporary architecture there is an increasing demand for transparency and curved shape. The Cold-Bending process is an effective and relatively inexpensive way of creating double curved surface glass. This thesis focuses on the shaping of a plate with the application of an out-of-plane displacement at its corner, also called cold-warping.

conjunto de aerogeneradores con el objeto de proveer de energía eléctrica para el alumbrado público y para una radio FM del lugar. Con el transcurso del tiempo se observó que los aerogeneradores no cargaban las baterías. Se desmontó entonces uno de ellos y se los ensayó en el Campus Universitario. Se evaluaron una curva de carga "real" de batería, y por consiguiente la cantidad de energía que es capaz de proveer el equipo y otras. Se observaron además, fallas en el controlador de carga; los resultados se presentan en este trabajo. Palabras clave: Aerogeneradores, ensayo de aerogenerador, cargas de acumuladores, sostenibilidad San Isidro es un pueblo de montaña, cuya calle principal se muestra en la Figura 1, ubicado a 3100 metros sobre el nivel del mar, 22.75º Latitud Sur, 65.25º Longitud Oeste, cuyas características fueron descriptas en un trabajo anterior [1]; en este lugar se instalaron los aerogeneradores que muestra la Figura 2, en la misma torre se instaló un anemómetro.

The Russian MC-21 commercial aircraft, developed by Irkut Corporation under the United Aircraft Corporation (UAC), represents a significant advancement in Russia's aerospace industry. This paper explores the features of the MC-21, its competitive position against Western counterparts like the Boeing 737 MAX and Airbus A320neo, and its potential impact on the global aviation industry. Additionally, it examines the benefits the MC-21 could bring to developing nations, including countries like Sri Lanka, in terms of affordability, accessibility, and economic opportunities in aviation.

The steering column is constructed by front suspension forks in most two wheelers. The paper focuses on the Finite Element Analysis of the suspension fork for motor bike, and developing an empirical equation in terms of internal diameter and central bush wall thickness. Finite element analysis has been done to verify the analytical analysis done with the help of thick wall theory. An empirical relation is necessary as different combinations of internal diameter and bush wall thickness are available in the industry. The empirical relation can be utilized to design a new fork for two wheelers.

The present study reports the abrasive wear behaviour of Al-Zn-Mg alloy in peak aged condition. The wear test was conducted on pin-on-disc machine. The hardness was reported and micrographs were also taken. Experimental design generated through Taguchi's technique was used to conduct experiments based on L 9 orthogonal array and signal-to-noise ratio, the-smaller-the better, was selected. ANOVA was employed to investigate the influence of wear parameters; applied load, sliding velocity, sliding time and abrasive particle size on specimens. The correlation was obtained by multiple general regression model. Finally, confirmation test was done to make a comparison between the experimental results foreseen from the mentioned correlation. SEM images of wear tracks and debris depicting mild, medium and severe wear were taken.

Ich bin all jenen zu Dank verpflichtet, die diese Arbeit möglich gemacht haben und mit ihrer unbezahlten Mühe in Form von Abschlussarbeiten und Projektarbeiten Vorarbeit geleistet haben. Zwar ist umfangreicher Aufwand oft in wenige Sätze und einzelne Bilder komprimiert (entsprechende Stellen sind gekennzeichnet), um dann allerdings darauf aufzubauen und weiter in die Tiefe zu gehen. Die Kürze verbirgt, wie wichtig diese Grundlagen sind. Zu nennen sind besonders Timon Eckstein, Bernd Eisenbarth und Gent Cerimi. Ich danke meinen Freund*innen, die meine Stimmung aufgebessert haben und die Rechtschreibung und Form der Arbeit verbessert haben. Danke an die Mitarbeiter im Robotiklabor, für Unterstützung und Ablenkung.

Two rectangular wing models with a hole have been designed and tested in the Duke University wind tunnel to better understand the effects of damage. A rectangular hole is used to simulate damage. The wing with a hole is modeled structurally as a thin elastic plate using the finite element method. The unsteady aerodynamics of the plate-like wing with a hole is modeled using the doublet lattice method. The aeroelastic equations of motion are derived using Lagrange's equation. The flutter boundary is found using the V-g method. The hole's location effects the wing's mass, stiffness, aerodynamics and therefore the aeroelastic behavior. Linear theoretical models were shown to be capable of predicting the critical flutter velocity and frequency as verified by wind tunnel tests.

The paper presents initial application and further development of a resilience engineering (RE) assessment method to the multiple remote towers (MRTWR) concept. The RE method is operationalised through a set of eight principles identified from existing RE literature. These principles are 1) Work-as-Done; 2) Varying conditions; 3) Signals and Cues; 4) Goal trade-offs; 5) Margins and adaptive capacity; 6) Coupling, interactions and cascades; 7) Timing, synchronisation and time scales; and 8) Under-specification and approximate adjustments. The application of the RE method to the concept of MRTWR has helped to understand the significance of the change and associate design requirements at a larger scale, focusing not only on the function of specific components, but on the ATM system as a whole. Results from this application show how understanding everyday operations (work-as-done) helps to evaluate the gaps between current and envisaged design of a new operational concept (MRTWR). Based on work-as-done the principles are used to develop design requirements how to enhance resilient performance of systems. Sharing this experience may offer practitioners and researchers from aviation and other domains the opportunity to build on lessons learnt from this application to investigate how resilience can be enhanced in their systems.

An in-house method of Newton-Euler inverse dynamics guidance based on a simplified airplane model in horizontal flight was proposed in a previous paper presented at NMAS 2018 workshop [1]. The goal was to guide the airplane between two locations situated at 100 km distance

In this work welded joints made of dissimilar steels: Maraging (18Ni) and 300M-ESR steel by the laser beam welding process (LBW) was evaluated. After the laser welding, different heat treatments were applied with the purpose to approximate the hardness of both steels in the fusion zone and heat affected zone. Subsequently, the joints were submitted to tensile and microhardness test for mechanical properties evaluation. Metallographic analyses of the welded joints were also performed and the microstructure and mechanical properties were correlated. The heat treatments applied after welding proved to be convenient for improvement of the hardness and the tensile strength. The increase in tensile strength due to the heat treatment applied after the welding was about 400 MPa. The laser welding process proved to be efficient to achieve the union of the proposed dissimilar steels and the heat treatment applied contributed to improve the mechanical properties.

From Pioneering Satellites to a Youth-Led Space Revolution As we celebrate National Science Day, I reflect on the extraordinary life of Professor Vasagam, a legendary figure synonymous with India's space program. More than just a scientist and educator, he was a visionary who possessed a remarkable ability to foresee the future, a future he tirelessly pursued through the power of technology. This memoir is my heartfelt reverence for his enduring legacy.

We investigated students' understanding of satellite motion around the Earth. For that purpose, we surveyed high-school and university students from Croatia. With the objective of gaining insight into teachers' understanding of students' abilities, physics teachers were asked to predict students' answers. The results of the study suggest that most students have difficulties with providing physically based explanations. They tend to approach such problems through the use of phenomenological primitives. Specifically, they tend to use the "closer is stronger" p-prim when attempting to identify the satellite orbit which would ensure receiving satellite television signal at a certain location paying no attention to the direction of the gravitational force. We found no statistically significant association between the students' ability to correctly explain the satellite motion and their educational background. The teachers considerably overestimate students' abilities. Generally, the results of this study suggest that diagram-based problem can be useful tool for probing students' understanding of satellite motion.

Gulfstream was responsible for the engineering design, fabrication, and instrumentation of the Quiet Spike experiment. NASA provided the F-15B test aircraft, aircraft modification and maintenance, aircraft instrumentation, integration of the Quiet Spike and instrumentation with the aircraft system, engineering support for ground and flight tests, flight planning and operations, hazard analysis and risk mitigation, and control room monitoring of test flights. NASA also maintained airworthiness and flight safety responsibility throughout the program. The Air Force Flight Test Center was responsible for helping NASA DFRC obtain flight clearance for air refueling the Quiet Spike equipped F-15. The 46 th Test Group allowed Mr. Tom Hill to support NASA during near field shock wave probing flights as the pilot for the probing NF-15B aircraft. Boeing provided simulator support to NASA to explore aircraft stability and control boundary issues in preparation for the Quiet Spike test project. It is noteworthy that the Gulfstream-NASA team was fully integrated in the accomplishment of this test project. NASA was involved at a relatively early stage of the Quiet Spike hardware development effort at Gulfstream, which aided greatly in integrating the test article with the aircraft. Gulfstream maintained on-site representation at NASA throughout the aircraft modification and flight program.