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Integrated aerodynamic-structural design optimizationEppard, William M. January 1987 (has links)
The introduction of composite materials in aircraft structures is having a profound effect on the design process. These materials permit the designer to tailor material properties to improve structural and aerodynamic performance. In order to obtain maximum benefits, a more integrated multidisciplinary design process is required. Furthermore, because of the complexity of the combined aerodynamic/structural design process numerical optimization methods are required.
The present research is focused on a major difficulty associated with the multidisciplinary design optimization process - its enormous computational cost. We consider two approaches for reducing this computational burden: (i) development of efficient methods for cross-sensitivity calculation using perturbation methods; and (ii) the use of approximate numerical optimization procedures. Our efforts are concentrated upon combined aerodynamic-structural optimization. Results are presented for the integrated design of a sailplane wing. The impact of our computational procedures on the computational costs of integrated designs are discussed. / M.S.
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Forgotten Legacies: The U.S. Glider Pilot Training Program and Lamesa Field, Texas, During World War IIGarner, Christian A. 05 1900 (has links)
Rapidly initiated at the national, regional, and local levels, the American glider pilot training program came about due to a perceived need after successful German operations at the outset of World War II. Although the national program successfully produced the required number of pilots to facilitate combat operations, numerous changes and improvisation came to characterize the program. Like other American military initiatives in the twentieth century, the War Department applied massive amounts of effort, dollars, and time to a program that proved to be short-lived in duration because it was quickly discarded when new technologies appeared. At the local level, the real loser was Lamesa, Texas. Bearing the brunt of these changes by military decision makers, the citizens of Lamesa saw their hard-fought efforts to secure an airfield fall quickly by the wayside in the wake of changing national defense priorities. As generations continue to pass and memories gradually fade, it is important to document and understand the relationship between this military platform that saw limited action and a small Texas town that had a similarly short period of significance to train the pilots who flew the aircraft.
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The instrumentation and initial analysis of the short-term control and stability derivatives of an ASK-I3 gliderBrowne, Keith R.J. 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2004.
220 leaves single printed pages ,preliminary pages i-xiv and numberd pages 1-188.Includes bibliography.list of figures and used a Hp Scanjet 8250 Scanner to pdf format (OCR), / ENGLISH ABSTRACT: This thesis describes the process followed to determine the short-term control and stability
derivatives of an ASK-13 glider (ZS-GHB). The short-term control and stability derivatives are
obtained by parameter estimation done using data recorded in flight. The algorithm used is the
MMLE3 implementation of a maximum likelihood estimator.
To collect the flight data sensors were installed in the ZS-GHB. Sensors measuring the
control surface deflections, translation acceleration, angular rates and the dynamic and static
pressure are needed to provide enough data for the estimation. To estimate accurate derivatives
specific manoeuvres were flown by the pilot, to ensure that all the modes of the glider were
stimulated.
The results reveal that the control and stability derivatives estimated from the flight data are
not very accurate but are still suitable to be used in simulating the glider's motion. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die proses wat gebruik is om die kort periode beheer en stabiliteit afgeleides
van 'n ASK-13 sweeftuig vas te stel. Die kort periode beheer en stabiliteit afgeleides is
verkry deur parameter afskatting op data wat gedurend vlugte van die sweeftuig opgeneem is.
Die algoritme wat gebruik is om die parameters af te skat is die MMLE3 voorstelling van 'n
maksimale moontlikheid afskatter.
Om vlug data te versamel sensore moes in die sweeftuig geinstalleer word. Die sensore meet
beheer oppervlak hoeke, versnellings, hoeksnellhede en die dinamies en statiese lugdruk om te
verseker dat daar genoeg data is vir die afskatting. Om die afgeskatte parameters akkuraad te
kry moet die loods spesefieke manoeuvres vlieg om seker te maak dat al die moduse van die
sweeftuig is gestimuleer.
Die resultate wat gelewer is 'n stel kort periode beheer en stabiliteit afgeleides wat nie
akkuraad is nie, maar wat weI goed genoeg is or ie bewegings van die sweeftuig te simuleer.
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Data Visualization to Evaluate and Facilitate Targeted Data Acquisitions in Support of a Real-time Ocean Forecasting SystemHolmberg, Edward A, IV 13 August 2014 (has links)
A robust evaluation toolset has been designed for Naval Research Laboratory’s Real-Time Ocean Forecasting System RELO with the purpose of facilitating an adaptive sampling strategy and providing a more educated guidance for routing underwater gliders. The major challenges are to integrate into the existing operational system, and provide a bridge between the modeling and operative environments. Visualization is the selected approach and the developed software is divided into 3 packages: The first package is to verify that the glider is actually following the waypoints and to predict the position of the glider for the next cycle’s instructions. The second package helps ensures that the delivered waypoints are both useful and feasible. The third package provides the confidence levels for the suggested path. This software’s implementation is in Python for portability and modularity to allow for easy expansion for new visuals.
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Specifika provozování malého letiště / Specifics of operation of small airportPašková, Michaela January 2011 (has links)
This diploma thesis analyzes the operation of a small airport. It focuses on the status of this airport, on its history, infrastructure, air traffic control and services offered. There is also a comparison of small and large airport.
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Systém pro určování nadzemní výšky letajících objektů / System for Identifying Above Ground Level of Flying ObjectsBoba, Peter January 2016 (has links)
This master's thesis deals with design and development of a system for measuring altitude (height above ground level) of flying objects. It describes theoretical background related to altitude measurements in avionics as well as various techniques of altitude measuring. The measurement is conducted by HMD (Height measuring device) - embedded system which uses barometric pressure sensor to measure altitude. The main part of this thesis is dedicated to ground unit - a server running custom set of applications. Using this server and radio link, it is possible to send control commands to HMD, receive data, and propagate data into web application. Furthermore server acts as a data storage and is able to process and analyse data. The thesis also discusses the precision of the measurement and the data output. System was tested and used during several glider aerobatics competitions.
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The aeroelastic tailoring of a high aspect-ratio composite structure / Taeke Nicolai van den BoschVan den Bosch, Taeke Nicolai January 2014 (has links)
The aim of this investigation was to review literature for the most suitable aeroelastic tailoring analysis tools for long slender composite structures, and integrate them into an aeroelastic tailoring process.
The JS1C Revelation is a high performance sailplane made from modern composites, mostly carbon fibre. This has the advantage of being more rigid than traditional engineering materials, thereby reducing the effects of the twisting deflections on these long slender structures due to aerodynamic loads. The implementing of aeroelastic tailoring can create bend-twist couples for performance improvements. Composites enable the use of aeroelastic tailoring to improve gliding performance. Flaperon 3 of the JS1C 21 m was used as the design problem for aeroelastic tailoring.
Aeroelastic tailoring was done by analysing the flaperon structure at the different layup angles to determine the correct design point to tailor the structure to improve aerodynamic performance at thermalling and cruise, but mostly cruise since it accounts for 70% of the flight time.
The composite structure analysis tool has the objective to get results during concept design. This directed the line of research of analysis tools to a solution method of two dimensional cross-section mesh properties projected onto a one dimensional beam. The literature of Hodges had good verification and published data on the analysis tools.
The analysis tools comprised of three programs that were not very user friendly. Thus the author compiled a Matlab program as a user interface tool to run the three programs together. The aeroelastic tailoring process systematically works through the known design variables and
objectives, which are given as inputs to the analysis tool. The analysis tool plots the coupling data versus layup angle. From this the best layup angles for a sought-after bend-twist couple is used to aeroelastically tailor the wing.
The composite structure analysis tool’s accuracy was verified by analysing cantilever beam deflections and comparing the results with hand calculations and SolidWorks Simulation FEM results. The analysis tool’s accuracy was further verified by comparing the aerodynamic torsional load’s twist deflections with thin walled tube theory.
The analysis tool was validated by applying a torsional load at the tip of a JS1C production Flaperon 3 in an experimental setup and then comparing this result with the Flaperon 3 modelled in the analysis tool. These comparisons also ensured that the model’s composite material properties and the meshing of the flaperon cross-sectional properties were correct.
This aeroelastic tailoring was validated with the advantage of then being used to improve the aerodynamic performance of the JS1C Revelation 21 m tip’s flaperon. This improvement could be made by making use of a tailored bend-twist couple to reduce the effect of the aerodynamic load’s twist deflections.
A test sample of the JS1C 21 m flaperon 3 was used to validate aeroelastic tailoring. The test sample was designed to be 1 m in length and have all the specified tailoring coupling characteristics that could improve the aerodynamic performance of the JS1C 21 m flaperon 3. The test sample was manufactured according to Jonker Sailplanes manufacturing standards and experimentally set up with the same applied deflections as in the analysis tool. The calculated bend-twist values and the experimental setup results were similar with a negligible difference, assuming small displacements and an aspect ratio greater than 13; this confirmed that the PreVABS/VABS/GEBT composite structure analysis tool could be used in aeroelastic tailoring to predict and design the bend-twist couple needed to improve the aerodynamic performance of the JS1C 21 m.
While the twist behaviour of Flaperon 3 was improved by the tailored bend-twist couple, it was still necessary to add pre-twist as well, to fully address the effects of twisting by aerodynamic forces. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
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The aeroelastic tailoring of a high aspect-ratio composite structure / Taeke Nicolai van den BoschVan den Bosch, Taeke Nicolai January 2014 (has links)
The aim of this investigation was to review literature for the most suitable aeroelastic tailoring analysis tools for long slender composite structures, and integrate them into an aeroelastic tailoring process.
The JS1C Revelation is a high performance sailplane made from modern composites, mostly carbon fibre. This has the advantage of being more rigid than traditional engineering materials, thereby reducing the effects of the twisting deflections on these long slender structures due to aerodynamic loads. The implementing of aeroelastic tailoring can create bend-twist couples for performance improvements. Composites enable the use of aeroelastic tailoring to improve gliding performance. Flaperon 3 of the JS1C 21 m was used as the design problem for aeroelastic tailoring.
Aeroelastic tailoring was done by analysing the flaperon structure at the different layup angles to determine the correct design point to tailor the structure to improve aerodynamic performance at thermalling and cruise, but mostly cruise since it accounts for 70% of the flight time.
The composite structure analysis tool has the objective to get results during concept design. This directed the line of research of analysis tools to a solution method of two dimensional cross-section mesh properties projected onto a one dimensional beam. The literature of Hodges had good verification and published data on the analysis tools.
The analysis tools comprised of three programs that were not very user friendly. Thus the author compiled a Matlab program as a user interface tool to run the three programs together. The aeroelastic tailoring process systematically works through the known design variables and
objectives, which are given as inputs to the analysis tool. The analysis tool plots the coupling data versus layup angle. From this the best layup angles for a sought-after bend-twist couple is used to aeroelastically tailor the wing.
The composite structure analysis tool’s accuracy was verified by analysing cantilever beam deflections and comparing the results with hand calculations and SolidWorks Simulation FEM results. The analysis tool’s accuracy was further verified by comparing the aerodynamic torsional load’s twist deflections with thin walled tube theory.
The analysis tool was validated by applying a torsional load at the tip of a JS1C production Flaperon 3 in an experimental setup and then comparing this result with the Flaperon 3 modelled in the analysis tool. These comparisons also ensured that the model’s composite material properties and the meshing of the flaperon cross-sectional properties were correct.
This aeroelastic tailoring was validated with the advantage of then being used to improve the aerodynamic performance of the JS1C Revelation 21 m tip’s flaperon. This improvement could be made by making use of a tailored bend-twist couple to reduce the effect of the aerodynamic load’s twist deflections.
A test sample of the JS1C 21 m flaperon 3 was used to validate aeroelastic tailoring. The test sample was designed to be 1 m in length and have all the specified tailoring coupling characteristics that could improve the aerodynamic performance of the JS1C 21 m flaperon 3. The test sample was manufactured according to Jonker Sailplanes manufacturing standards and experimentally set up with the same applied deflections as in the analysis tool. The calculated bend-twist values and the experimental setup results were similar with a negligible difference, assuming small displacements and an aspect ratio greater than 13; this confirmed that the PreVABS/VABS/GEBT composite structure analysis tool could be used in aeroelastic tailoring to predict and design the bend-twist couple needed to improve the aerodynamic performance of the JS1C 21 m.
While the twist behaviour of Flaperon 3 was improved by the tailored bend-twist couple, it was still necessary to add pre-twist as well, to fully address the effects of twisting by aerodynamic forces. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
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Modelling And Analysis Of Fish Inspired Ionic Polymer Metal Composite Flapping FinsKarthigan, G 05 1900 (has links) (PDF)
Ionic polymer metal composites (IPMC) are a new class of smart materials that have attractive characteristics such as muscle like softness, low voltage and power consumption, and good performance in aqueous environments. Therefore, there is a significant motivation for research on design and development of IPMC based biomimetic propulsion systems for underwater vehicles. In aerospace, underwater vehicles finds application for forensic studies of spaceship wrecks, missile fragments and any airplane accidents in sea and ocean terrains. Such vehicles can also survey moons and planets that house water oceans. Among biomimetic swimming systems, fish inspired swimming has gained interest since fish like swimming provides high maneuverability, high cruising speed, noiseless propulsion and efficient stabilization compared to conventional propulsion systems. In this work, the paired pectoral fin based oscillatory propulsion using IPMC for aquatic propulsor applications is studied. Dynamic characteristics of IPMC fin are analyzed using numerical simulations and optimization is used to improve the fin design. A complex hydrodynamic function is used to describe the behavior of an active IPMC fin actuator in water. The structural model of the IPMC fin is obtained by modifying the classical dynamic equation for a slender beam to account for the electromechanical dynamics of the IPMC beam in water. A quasi-steady blade element model that accounts for unsteady phenomena such as added mass effects, dynamic stall, and the cumulative Wagner effect is used to estimate the hydrodynamic performance of the flapping fin. It is shown that the use of optimization methods can lead to significant improvement in performance of the IPMC fin. Further, three fish species with high performance flapping pectoral fin locomotion are chosen and performance analysis of each fin design is conducted to discover the better configurations for engineering applications. Dynamic characteristics of IPMC actuated flapping fins having the same size as the actual fins of three different fish species, Gomphosus varius, Scarus frenatus and Sthethojulis trilineata, are also analyzed. Finally, a comparative study is performed to analyze the performance of the three different biomimetic IPMC flapping pectoral fins.
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Galerie letecké techniky a tradic letectví na letišti Medlánky v Brně / Gallery aviation technology and traditions of aviation at the airport Medlánky in BrnoBělehradová, Věra January 2016 (has links)
Sport Airport complex Brno-Medlánky is nestled in the undulating hilly terrain in fields just beyond populated areas in Brno-Medlánky. The history of the airport dates back to 1924 when it was built the first wooden hangar for training purposes glider flights. Current state urban of airport is orderless. The aim is to streamline the complex and give it the order, allowing easy and efficient orientation in the space. The main intervention was the creation of a new central building - Aviation Museum. The concept of the design is based on the division of the whole area into two branches - communication axes, based on the mass preserved historic wooden hangars. Between the two communication arms is inserted a central axis on which is located the heart of the complex - Aviation Museum. It is a building organic form, inspiring axially symmetric wingspan (bird, airplane, beetle). It is this symmetry axis of the building creates a view towards building on the runway. Mass of the building used by the sloping terrain and is partially sunk under the ground. Building volume follows an upward slope from the outside and blends with the surrounding terrain. The internal layout consists of three floors, one of them is completely sunk below ground level and second half. The main entrance to the gallery is located in the uppermost floors, the direction of the exhibition is therefore directed downwards into the basement. The exposition is divided into six parts: RC models exposure, gliders exposure, powered aircraft exposure, screening room, children's exposure and air trainers. Other areas consist of building technical facilities. In the basement there is a workshop with aircraft lift, with the possibility of placement unexposed aircrafts. The supporting system of the building consists of two parts: reinforced concrete tubs and arched steel structure with a span of 50m.
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