Analysis of Annular Plug Nozzle Flowfield

The flowfields associated with truncated annular plug nozzles of varying lengths are studied both experimentally and using computational tools. The nozzles are designed to observe wake structure transition for the range of pressure ratios considered. A classification of the open wake regime is proposed for comparing and analyzing the plug flowfields. The three-dimensional relief experienced by the annular plug flow leads to greater wave interactions on the plug surface as compared with linear plug flow, resulting in a delayed transition of the base wake. The Reynolds averaged Navier-Stokes based solvers employed in the studies could predict the plug surface flow accurately, whereas they exhibited limitations with regard to plug base flow predictions. Based on the experimental data generated, an empirical model for predicting closed wake base pressure is proposed and compared with other models available in literature.

Flow Investigation of Linear Cluster Plug Nozzle

Computational and experimental tools have been used to understand the linear cluster plug nozzle flowfield for a range of pressure ratios. The experimental cluster configuration is arrived at from a linear plug nozzle by introducing splitter plates in the primary nozzle, and computational analysis of corresponding geometry is also carried out. The flow development on the plug surface has been analyzed for two different cluster module spacings. The interactions between the cluster module jets is a complex one with a three-dimensional shock structure because of the differential end condition the shock experiences on the plug wall and freejet boundary. A prominent streamwise vorticity resulting from curvature of the shock is also seen along the length of the plug downstream of the module junctions. The out-of-phase wave interactions occurring along the module centerline and the splitter plate centerline, resulting in a wavy surface-limiting streamline pattern, particularly at lower pressure ratios, is explained.

Acordo Aeroespacial Teuto-Brasileiro (1969-1989; 1990-2001 e 2002-2011): uma cooperação complementar

Este projeto de dissertação se propõe a analisar a cooperação aeroespacial entre o Brasil e a Alemanha de 1969 a 2011 em três recortes temporais: 1969 a 1989, 1990 a 2001 e 2002 a 2011. Seguindo as bases teóricas de classificação da CID (Cooperação Internacional para o Desenvolvimento), e apoiada em pesquisa de campo conduzida em ambos os países, este trabalho apresenta um novo conceito de cooperação que, até onde a pesquisa bibliográfica aqui conduzida avaliou, constitui uma contribuição original deste trabalho: a Cooperação Complementar. A cooperação aeroespacial teuto-brasileira é pouco conhecida e divulgada, embora tenha completado vigorosas quatro décadas de exitosa existência. A conclusão de êxito desta cooperação encontrou lastro em pesquisa de campo conduzida pela autora no Brasil (IAE Instituto de Aeronáutica e Espaço) e na Alemanha (DLR Deutsche Zentrum für Luft- und Raumfahrt), consubstanciada por quatro entrevistas (SILVA, 2011a), (SILVA, 2011c), (SILVA, 2011d) e (SILVA, 2011e) realizadas junto a importantes representantes destes dois centros. Os conhecimentos extraídos por meio destas entrevistas agregaram, no entender desta autora, importantes informações à bibliografia específica e relativamente escassa disponível em ambos os países.O êxito defendido nesta dissertação fundamenta-se não apenas na longevidade advinda dos 40 anos de existência desta Cooperação, na sua capacidade de renovação e na complementaridade atingida, mas sobretudo pela consecução dos diversos objetivos técnico-científicos integrantes do escopo do referido Tratado, muitos dos quais responsáveis por importantes desdobramentos de tecnologias em outras áreas do saber, tais como o projeto DEBRA 25 (SCHUSTER, 2011), de energia eólica, e o projeto VLS (Veículo Lançador de Satélites), que utiliza como seus motores os foguetes desenvolvidos no escopo desta Cooperação.

Rockets.

Aprobada por expertos en educación la obra trata temas de la vida real. Texto con frases sencillas y repetición de palabras para motivar al niño a desarrollar su interés por la lectura y la curiosidad por el mundo en que vive.Tiene glosario alfabético.

Proposal of architecture for launcher systems of unguided sounding rockets

This work presents a proposal of systemic architecture, to make automatic actions in the positioning of launch rail of unguided sounding rockets, which are based on a supervision system, a programmable logical controller, a sensory and actuators, available in Brazilian national market. Copyright © 2006 Society of Automotive Engineers, Inc.

Caracterização mecânica e microestrutural do aço MARAGING 300, soldado a plasma e submetidas a reparos

Pós-graduação em Engenharia Mecânica - FEG

Innovative Man Machine Interfaces In Aeronautics

The research activity focused on the study, design and evaluation of innovative human-machine interfaces based on virtual three-dimensional environments. It is based on the brain electrical activities recorded in real time through the electrical impulses emitted by the brain waves of the user. The achieved target is to identify and sort in real time the different brain states and adapt the interface and/or stimuli to the corresponding emotional state of the user. The setup of an experimental facility based on an innovative experimental methodology for “man in the loop" simulation was established. It allowed involving during pilot training in virtually simulated flights, both pilot and flight examiner, in order to compare the subjective evaluations of this latter to the objective measurements of the brain activity of the pilot. This was done recording all the relevant information versus a time-line. Different combinations of emotional intensities obtained, led to an evaluation of the current situational awareness of the user. These results have a great implication in the current training methodology of the pilots, and its use could be extended as a tool that can improve the evaluation of a pilot/crew performance in interacting with the aircraft when performing tasks and procedures, especially in critical situations. This research also resulted in the design of an interface that adapts the control of the machine to the situation awareness of the user. The new concept worked on, aimed at improving the efficiency between a user and the interface, and gaining capacity by reducing the user’s workload and hence improving the system overall safety. This innovative research combining emotions measured through electroencephalography resulted in a human-machine interface that would have three aeronautical related applications: • An evaluation tool during the pilot training; • An input for cockpit environment; • An adaptation tool of the cockpit automation.

Test Facility to Study Surface-Interaction Processes for Particle Detection in Space

The Imager for Low Energetic Neutral Atoms test facility at the University of Bern was developed to investigate, characterize, and quantify physical processes on surfaces that are used to ionize neutral atoms before their analysis in neutral particle-sensing instruments designed for space research. The facility has contributed valuable knowledge of the interaction of ions with surfaces (e.g., fraction of ions scattered from surfaces and angular scattering distribution) and employs a novel measurement principle for the determination of secondary electron emission yields as a function of energy, angle of incidence, particle species, and sample surface for low particle energies. Only because of this test facility it was possible to successfully apply surface-science processes for the new detection technique for low-energetic neutral particles with energies below about 1 keV used in space applications. All successfully flown spectrometers for the detection of low-energetic neutrals based on the particle–surface interaction process use surfaces evaluated, tested, and calibrated in this facility. Many instruments placed on different spacecraft (e.g., Imager for Magnetopause-to-Aurora Global Exploration, Chandrayaan-1, Interstellar Boundary Explorer, etc.) have successfully used this technique.

Metaphor and Genre: An Approach to improve the learning process of English for Aeronautics

This study suggests a theoretical framework for improving the teaching/ learning process of English employed in the Aeronautical discourse that brings together cognitive learning strategies, Genre Analysis and the Contemporary theory of Metaphor (Lakoff and Johnson 1980; Lakoff 1993). It maintains that cognitive strategies such as imagery, deduction, inference and grouping can be enhanced by means of metaphor and genre awareness in the context of content based approach to language learning. A list of image metaphors and conceptual metaphors which comes from the terminological database METACITEC is provided. The metaphorical terms from the area of Aeronautics have been taken from specialised dictionaries and have been categorised according to the conceptual metaphors they respond to, by establishing the source domains and the target domains, as well as the semantic networks found. This information makes reference to the internal mappings underlying the discourse of aeronautics reflected in five aviation accident case studies which are related to accident reports from the National Transportation Safety Board (NTSB) and provides an important source for designing language teaching tasks. La Lingüística Cognitiva y el Análisis del Género han contribuido a la mejora de la enseñanza de segundas lenguas y, en particular, al desarrollo de la competencia lingüística de los alumnos de inglés para fines específicos. Este trabajo pretende perfeccionar los procesos de enseñanza y el aprendizaje del lenguaje empleado en el discurso aeronáutico por medio de la práctica de estrategias cognitivas y prestando atención a la Teoría del análisis del género y a la Teoría contemporánea de la metáfora (Lakoff y Johnson 1980; Lakoff 1993). Con el propósito de crear recursos didácticos en los que se apliquen estrategias metafóricas, se ha elaborado un listado de metáforas de imagen y de metáforas conceptuales proveniente de la base de datos terminológica META-CITEC. Estos términos se han clasificado de acuerdo con las metáforas conceptuales y de imagen existentes en esta área de conocimiento. Para la enseñanza de este lenguaje de especialidad, se proponen las correspondencias y las proyecciones entre el dominio origen y el dominio meta que se han hallado en los informes de accidentes aéreos tomados de la Junta federal de la Seguridad en el Transporte (NTSB)

Long liquid bridges aboard sounding rockets

Large free liquid volumes, 30 mm in diameter and 80 mm long, anchored to coaxial discs, have been achieved during a sounding-rocket flight. As these flights provide some six minutes of microgravity and the formation of the liquid column takes only a matter of seconds, ample time is left for experimentation. The results of these trials are presented, and the equipment used to obtain them is briefly described.