8,827 research outputs found
A generic operational simulation for early design civil unmanned aerial vehicles
No full textContemporary aerospace programmes often suffer from large cost overruns, delivery delays and inferior product quality. This is caused in part by poor predictive quality of the early design phase processes with regards to the operational environment of a product. This paper develops the idea of a generic operational simulation that can help designers to rigorously analyse and test their early product concepts. The simulation focusses on civil Unmanned Air Vehicle products and missions to keep the scope of work tractable. The research agenda is introduced along with ideas, initial results and future work. Designers specify details about their product, its environment and anticipated operational procedures. The simulation returns information that can help to estimate the value of the product using the value-driven design approach. Information will include recurring and non-recurring mission cost items. The research aim is to show that an operational simulation can improve early design concepts, thereby reducing delays and cost overruns. Moreover, a trade-off between mission fidelity and model generality is sought along with a generic ontology of civil Unmanned Air Vehicle missions and guidelines about capturing operational informatio
Evaluating design decisions in real-time using operations modelling
No full textContemporary design processes of large aerospace products are rigidly focused on customer specifications in order to meet their expectations. Life cycle costs, design space exploration and value engineering are neglected, often leading to substantial cost overruns and delivery delays. Moreover, customer specifications are not scrutinized and design decisions are made ignoring potential operational knowledge. Value-driven design suggests a new approach using flexible customer specifications in order to find optimal designs by exploring the solution space. One aspect of this optimization is the simulation of the anticipated operational life of a product in order to gain operational knowledge and analyse customer specifications. This paper suggests that an operational simulation can be used actively or reactively by designers during the design process to improve a product. It is investigated how an operational simulation can act as a design decision support tool and how it can react to customer specifications. Answers are presented by means of a simulation model recreating the operational life of a Search-and-Rescue Unmanned Air Vehicle developed in parallel at the University of Southampton. The simulation's ability for acting as a decision support tool is explored by conducting a fuel tank size optimization. Reactive capabilities are explored by calculating the surplus value of using UAVs. This exemplifies the derivation of product specifications as the simulation reveals the value and hence usefulness of given customer specifications. It is shown that operational simulations benefit designers and overall product value by analysing product specifications and guiding designers to more informed design decision
Private James Dem(m)ing leave of absence
No full textDocument written by Colonel Hiram Du Puy granting Private James Dem(m)ing of the 8th Ohio Volunteer Infantry a leave of absence from Camp Dennison, June 1861
Design and flight test of a civil unmanned aerial vehicle for maritime patrol: the use of 3D-printed structural components
No full textThis paper describes the design of the “Spotter” unmanned aerial vehicle, developed by the University of Southampton as part of the 2SEAS-3i European Interreg project. Spotter is a twin engine, 4m wing span, fixed-wing aircraft which has been designed to perform long-endurance, all-weather patrol missions in coastal and maritime environments. Reliability and safety have been among the strongest design drivers of this project; Spotter is able to survive the failure of one engine and of any single control surface. A modular approach has been adopted for the payload unit in order to allow the users to rapidly interchange the sensors required to perform different missions.One of the most innovative aspects of Spotter is the extensive use of the Selective Laser Sintering (SLS) technology (also known as 3D printing) for many of the components of its airframe. By eliminating tooling and manual labour, the 3D printing technology allows the designer to produce complex and high-performance structures at a relatively low cost and within hours of the completion of the design. Spotter and a sub-20kg version, codenamed 2SEAS-20, have undergone an extensive flight test campaign, totalling hundreds of autonomous flights (including autonomous take-off and landings) and many flight hours. This has provided the opportunity to test the reliability and robustness of the system and to gain a deeper insight into the opportunities and problems presented by the use of 3D printed structures for large airframe components
Mapping customer needs to engineering characteristics: an aerospace perspective for conceptual design
No full textDesigning complex engineering systems, such as an aircraft or an aero-engine, is immensely challenging. Formal Systems Engineering (SE) practices are widely used in the aerospace industry throughout the overall design process to minimise the overall design effort, corrective re-work, and ultimately overall development and manufacturing costs. Incorporating the needs and requirements from customers and other stakeholders into the conceptual and early design process is vital for the success and viability of any development programme. This paper presents a formal methodology, the Value-Driven Design (VDD) methodology that has been developed for collaborative and iterative use in the Extended Enterprise (EE) within the aerospace industry, and that has been applied using the Concept Design Analysis (CODA) method to map captured Customer Needs (CNs) into Engineering Characteristics (ECs) and to model an overall ‘design merit’ metric to be used in design assessments, sensitivity analyses, and engineering design optimisation studies. Two different case studies with increasing complexity are presented to elucidate the application areas of the CODA method in the context of the VDD methodology for the EE within the aerospace secto
Strategic jet engine System design in light of uncertain fuel and carbon prices
No full textSince the Wright brothers took to the skies over 100 years ago, aviation has been powered by fossil fuels. This dependency will not be markedly reduced within the next two decades despite higher and more erratic fuel prices that result from increasingly restricted access to crude oil. Climate change will also force regulators to increase the price of CO2 emissions so that there is an even greater incentive to operate fuel efficient aircraft. This project therefore aims to investigate how the profit generated by a short-range jet engine can be made robust to uncertain fuel and carbon prices in 2030 by applying the Surplus Value Methodology in conjunction with Robust Design techniques
Rapid development of bespoke sensorcraft: a proposed design loop
No full textThe ability to quickly fabricate sensorcraft, or other small unmanned aircraft, via additive manufacturing techniques opens a range of new possibilities for the design and optimization of these vehicles. In this paper we propose a design loop that makes use of surrogate modeling and additive manufacturing to reduce the design and optimization time of scientific sensorcraft. Additive manufacturing reduces the time and effort required to fabricate a complete aircraft, allowing design iterations to be quickly manufactured and flight tested. Co-Kriging surrogate models allow data collected from test flights to correct Kriging models trained with numerically simulated data. The resulting model provides physically accurate and computationally cheap aircraft performance predictions. A global optimizer is used to search this model to find an optimal design for a bespoke aircraft. This paper presents the design loop and the progress made in implementing this design loop. Results are shown from Kriging models trained using numerically simulated data. Progress towards extracting aerodynamic data from flight testing small unmanned aircraft is also documented
From radiosonde to papersonde: the use of conductive inkjet printing in the massive atmospheric volume instrumentation system (MAVIS) project
No full textA promising method for the collection of atmospheric data is the en masse release of ‘flocks’ of nano Unmanned Aerial Vehicles (UAVs) from meteorological balloons. These UAVs would need to be lightweight, cheap, and disposable. Recent advances in Conductive Inkjet Printing (CIP) have allowed the fabrication of electronic circuits onto thin substrates, such as paper. We demonstrate that the direct printing of circuit tracks onto photo paper will allow the creation of such aircraft, which are not only disposable, but biodegradable. We present a prototype ‘Papersonde’, which features a directly printed circuit with a microprocessor, transceiver, barometer and temperature sensor. We also describe in detail the fabrication steps required to create the Papersonde. It is hoped that this circuit will form the basis of the nano UAVs we create for the Massive Atmospheric Volume Instrumentation System (MAVIS) project
Polyphony and the anxiety of influence in the fiction of Henry James
No full textJames's fiction, especially in the Middle Phase, centres
on the figure of the artist and is characterized by, the two
interrelated aspects which previous criticism has largely
overlooked: the Bakhtinian 'polyphonic' -creation of
'author-thinkers'; and the conflict between ephebes and
precursors, for which Harold-Bloom's concept of 'the-anxiety of
influence' is the most illuminating model. Polyphony is the
narrative mode, and influence is the intra-artistic, theme.
These, as the Introduction to the thesis makes clear, are
rehearsed in James's inaugural novel, Roderick Hudson. Rowland
Mallet is an author-thinker, and his failure is caused by
authorial limitations. His monologism -is impaired by his
mistaking empathy for the authorial sympathy. Likewise,
Hudson's failure does not arise from a mercurial temperament,
but from a polyphonic shortcoming: not possessing the power of
fiction to contain the fiction of power in, his mentor. And the
relationships among the three artists - Gloriani, Hudson and
Singleton - perfectly exemplify the Bloomian-theme. It is these
two concepts, polyphony and influence, which are the major
preoccupation in the Middle Phase; as, the works chosen
demonstrate. These are a novella, a novel, and a number of
short stories all of which have been unjustifiably neglected.
Chapter One, on The Aspern Papers, argues that Tina Bordereau,
far from being, the artless victim seen by many critics,
actually challenges and defeats the narrator by the very form
of her narrative. Her 'realist' discourse undermines his
language of 'romance', and shows up its internal unstability.
Chapter Two is an extensive study of the critical reception of
The Tragic Muse. The most common areas of critical attention
have been its contemporary topicality, its relation to previous
novels on similar themes, and the possible genealogy of Gabriel
Nash. Those have all missed the core of the work. - Chapter Three
demonstrates how polyphony and the anxiety of influence make
the novel what it really is. Influence arises from the
juxtaposition of, and the wrestling between, artistic ephebes
and their precursors (Nick and Nash,, Miriam and Madame Carre).
The dialogic quality defined by Bakhtin is crucial to the
proper, and even-handed, characterization of all, the conflicts
in the novel. And since most of James's tales in the eighties
and nineties -are about 'masters - and acolytes, the anxiety of
influence remains central. Chapter Four is a study of 'The
Author of Beltraffiol' and 'The Lesson of the Master'. Again the
characters' manipulations are a crucial focus in a way that
G6rard Genette's terminology helps to illuminate. The fact that
the ephebe is the author-thinker emphasizes the inextricability
of the Bakhtinian and the Bloomian in James. Just as
polyphony offers a different focus for explicating the poetics
of James's fiction; so the ephebal conflict provides the basis
for a fresh perception of James's own artistic struggle
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