Nowadays, the competition among airlines seriously depend upon the saving operating costs, with the premise that not to degrade its services quality. Especially in the face of increasingly scarce oil resources, reducing fleets operational fuel consumption, is an important means to improve profits. Aircraft fuel economy is determined by operational management strategies and application technologies. The application of technologies mainly refers to airplane’s engine performance, Weight efficiency and aerodynamic characteristics. A market competitive aircraft should thoroughly consider to all of these aspects. Transport aircraft aerodynamic performance mainly is determined by wing’s properties. Wings that are optimized for efficient flight in cruise conditions need to be fitted with powerful high-lift devices to meet lift requirements for safe takeoff and landing. These high-lift devices have a significant impact on the total airplane performance. The aerodynamic characteristics of the wing airfoil will have a direct impact on the aerodynamic characteristics of the wing, and the wing’s effective cruise hand high-lift configuration design has a significant impact on the performance of transport aircraft. Therefore, optimizing the design is a necessary airfoil design process. Nowadays engineering analysis relies heavily on computer-based solution algorithms to investigate the performance of an engineering system. Computational fluid dynamics (CFD) is one of the computer-based solution methods which are more widely employed in aerospace engineering. The computational power and time required to carry out the analysis increases as the fidelity of the analysis increases. Aerodynamic shape optimization has become a vital part of aircraft design in the recent years. Since the aerodynamic shape optimization (ASO) process with CFD solution algorithms requires a huge amount of computational power, there is always some reluctance among the aircraft researchers in employing the ASO approach at the initial stages of the aircraft design. In order to alleviate this problem, statistical approximation models are constructed for actual CFD algorithms. The fidelity of these approximation models are merely based on the fidelity of data used to construct these models. Hence it becomes indispensable to spend more computational power in order to convene more data which are further used for constructing the approximation models. The goal of this thesis is to present a design approach for assumed wing airfoils; it includes the design process, multi-objective design optimization based on surrogate modelling. The optimization design stared from a transonic single-element single-objective optimization design, and then high-lift configurations were two low-speed conditions of multi-objective optimization design, on this basis, further completed a variable camber airfoil at low speed to high-lift configuration to improve aerodynamic performance. Through this study, prove a surrogate based model could be used in the wing airfoil optimization design.

A set of techniques is developed that allows the incorporation of flight dynamics metrics as an additional discipline in a high-fidelity aerodynamic optimization. Specifically, techniques for including static stability constraints and handling qualities constraints in a high-fidelity aerodynamic optimization are demonstrated. These constraints are developed from stability derivative information calculated using high-fidelity computational fluid dynamics (CFD). Two techniques are explored for computing the stability derivatives from CFD. One technique uses an automatic differentiation adjoint technique (ADjoint) to efficiently and accurately compute a full set of static and dynamic stability derivatives from a single steady solution. The other technique uses a linear regression method to compute the stability derivatives from a quasi-unsteady time-spectral CFD solution, allowing for the computation of static, dynamic and transient stability derivatives. Based on the characteristics of the two methods, the time-spectral technique is selected for further development, incorporated into an optimization framework, and used to conduct stability-constrained aerodynamic optimization. This stability-constrained optimization framework is then used to conduct an optimization study of a flying wing configuration. This study shows that stability constraints have a significant impact on the optimal design of flying wings and that, while static stability constraints can often be satisfied by modifying the airfoil profiles of the wing, dynamic stability constraints can require a significant change in the planform of the aircraft in order for the constraints to be satisfied.

The purpose of this thesis is to create basic design guidance for tall buildings and their aerodynamic modifications as a resource for architects, engineers, developers, and students. It aims to make a contribution to and strengthen particularly the architect&amp / #8217 / s understanding of tall building design, that requires a high level of interdisciplinary approach, by providing a broad overview of the tall building with its general concepts / to demonstrate the importance of human element as a critical component in the design of tall building by clarifying the wind forces and resulting movements which cause discomfort to building occupants and create serious serviceability issues / and to show the significance of aerodynamic modifications as an effective design approach in terms of mitigating wind excitation. In order to achieve these purposes, firstly, a comprehensive literature survey, which includes the definition, emergence and historical background, basic planning and design parameters, and lateral load considerations of tall buildings is presented. Following a structural classification of the tall buildings, wind excitation, its negative effects on occupant comfort and serviceabilty issues, and the methods to control wind excitation are studied. Finally, the significance of aerodynamic modifications against wind excitation, which include modifications of building&amp / #8217 / s cross-sectional shape and its corner geometry, sculptured building tops, horizontal and vertical openings through-building, are presented from the scholarship on this topic.

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The technology of UAV (Unmanned Aerial Vehicle) has developed since its conception many years ago. UAVs have several features such as, computerised and autonomous control without the need for an on-board pilot. Therefore, there is no risk of loss of life and they are easier to maintain than manned aircraft. In addition, UAVs have an extended range/endurance capability, sometimes for several days. This makes UAVs attractive for missions that are typically

CD-ROM containing source codes of the numerical scheme (appendix A) is attached to back cover. / Includes bibliographical references (leaves 459-472). / System requirements for accompanying CD-ROM: Macintosh or IBM compatible computer. Other requirements: Adobe Acrobat Reader. / xxxvi, 473 leaves ; ill. ; 30 cm. + 1 computer optical disk (4 3/4 in.) / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A numerical scheme, based on discrete-vortex and surface-vorticity boundary-integral methods, has been developed for stimulating time dependent, two-dimensional, viscous flow over arbitary arrays of solid bodies of arbitary cross-section / Thesis (Ph.D.)--Adelaide University, Dept. of Mechanical Engineering, 2001

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Anjaneyulu Krothapalli, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed June 14, 2005). Document formatted into pages; contains xx, 224 pages. Includes bibliographical references.

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Christopher K. W. Tam, Florida State University, College of Arts and Sciences, Dept. of Mathematics. Title and description from dissertation home page (viewed Sept. 21, 2005). Document formatted into pages; contains xv, 118 pages. Includes bibliographical references.

L’apprentissage du langage parlé nécessite un contrôle musculaire très précis des différents organes intervenant dans la production de la parole. La production de sons voisés, qui résulte de l’auto-oscillation des cordes vocales, est notamment influencée par l’ensemble du système phonatoire, du diaphragme jusqu’aux lèvres. Les travaux réalisés dans le cadre de cette thèse s’inscrivent dans un contexte de modélisation physique de la parole. Les objectifs s’articulent autour de la compréhension des phénomènes physiques gouvernant la production de sons voisés. Les études sont appliquées à des cas pour lesquels le contrôle de la production est fortement altéré, lorsque le locuteur souffre de pertes auditives importantes. Dans ce cas de figure, les interactions physiques peuvent jouer un rôle important dans l’apparition de troubles de la production. La démarche adoptée consiste alors dans un premier temps à observer les phénomènes étudiés au moyen de mesures in vivo puis à proposer des modèles théoriques mécanique, aérodynamique et acoustique permettant de les décrire. Ensuite, les modèles sont validés en comparant avec des mesures réalisées sur une maquette de l’appareil phonatoire. Finalement,des simulations numériques temporelles basées sur un modèle à deux masses pour décrire le comportement mécanique des cordes vocales, permettent de tester les modèles physiques pour des cas concrets de production. La première étude se concentre sur les sauts de fréquence fondamentale qui accompagnent les transitions involontaires entre deux mécanismes laryngés lors de la production d’une voyelle. Les travaux expérimentaux et numériques montrent qu’une transition de mécanisme laryngé est la manifestation d’une bifurcation du système laryngé et que ces bifurcations se produisent lors d’une variation de la raideur des cordes vocales, de la pression sous-glottique, de l’aire glottique initiale ou bien de la longueur des résonateurs acoustiques. Les modèles théoriques permettent de reproduire les sauts de fréquence fondamentale observés expérimentalement. Ils sont utilisés pour étudier les différentes stratégies motrices responsables de ces sauts de fréquence. La deuxième étude porte sur la production de consonnes plosives, en particulier sur les effets de la réalisation d’une occlusion du conduit vocal sur l’arrêt puis l’apparition de l’oscillation des cordes vocales. Les simulations de séquences voyelle - plosive bilabiale non voisée (/p/)-voyelle effectuées montrent que l’expansion passive de la cavité supraglottique est à l’origine du maintien de l’auto-oscillation des cordes vocales après la fermeture du conduit vocal et que l’augmentation de la longueur du conduit vocal a pour effet de réduire le délai entre le relâchement de l’occlusion et l’apparition de l’oscillation des cordes vocales. Ces résultats impliquent que l’articulation joue un rôle considérable sur le mode de voisement (voisée ou non voisée) de la consonne et sur la valeur du Voice Onset Time pour une consonne plosive non voisée. / Language learning requires specific muscle control of all organs that contribute to speech production. Voiced sounds production, which results from vocal folds self oscillation, is especially influenced by the whole phonatory apparatus, from diaphragm to lips. The general background of this thesis is the physical modeling of speech production and the objectives are motivated by a better comprehension of physical phenomena occurring in voiced sounds production. In the frame of this work, studies are focused on cases where speech production control is impaired, for example when the speaker suffers from an important hearing loss. In this situation, physical interactions can play an important role in speech production disorders emergence. The approach adopted here is first to observe the studied phenomena thanks to invivo measurements then to describe them thanks to theoretical models. Thereafter, the models are validated by comparing theoretical results with measurements performed on a replica of the phonatory apparatus. Finally, numerical simulations in the time domain, based on a two-mass model, allow to apply physical models to specific speech production occurrences.The first study deals with fundamental frequency jumps that are observed during an unvoluntary transition between two different laryngeal mechanisms in case of vowel production.Experimental and numerical results highlight that a transition between two different laryngeal mechanisms is a symptom of the laryngeal system bifurcation, and that such bifurcation occurs during a variation of the vocal folds stiffness, the subglottal pressure,the prephonatory glottal area or the acoustic resonators length. The theoretical models allow to simulate the fundamental frequency jumps that are observed experimentally. They are used to study the different motor strategies responsible for these frequency jumps.The second study deals with plosive consonants production, and in particular with the effectsof a vocal tract occlusion on voicing offset and onset. Simulations of vowel – voiceless plosive - vowel production highlight that passive expansion of the supraglottal cavity is responsible for the voicing extension after vocal tract closure, and that increase of the vocal tract length leads to a shorter delay between the vocal tract occlusion release and the voicing onset. These results highlight that the articulation plays an important role in voicing (voiced or voiceless) and in voice-onset-time value for a voiceless plosive.

Este trabalho tem como eixo principal a avaliação experimental de texturas para superfícies de pás com intuito de aumentar a eficiência de ventoinhas de pequeno porte em relação às ventoinhas padrão (com pás lisas), através das variáveis também investigar de forma qualitativa o potencial de diferentes topologias no efeito estético. A ênfase está na modelagem de texturas para a superfície das pás de cada ventoinha, que foram trabalhadas a fim de diminuir a quantidade de escoamento de ar necessária para o funcionamento da mesma. Para os testes feitos, foi escolhida como base a ventoinha de um Cooler, utilizada geralmente para arrefecimento do processador de computadores, que devido à pequena escala proporciona facilidade de manuseio. A análise aconteceu através dos resultados que cada superfície projetada apresentou no túnel aerodinâmico, assim permitindo avaliar a eficiência em relação à superfície lisa. Os parâmetros como a velocidade do escoamento de ar, velocidade do corpo de prova e as relações entre essas velocidades foram definidas por um método específico para este trabalho. Espera-se como resultado que o uso das texturas com a distribuição de massa adequada consiga reduzira necessidade de escoamento de ar para o funcionamento do produto, tornando o processo de rotação mais eficiente e estético. / This work has as main shaft creating textures for surfaces of blades in order to increase the efficiency of small fans over its variables. The emphasis is on modeling the surface texture of the blades of each fan to be worked in order to reduce the need to wind to start the start of movement thereof. For testing efficiency it was chosen as the basis of a cooler fan, commonly used for cooling computers, which due to the small scale provides an ease of handling. The analysis of the results that happen through each projected surface present in the wind tunnel, thus allowing to evaluate the efficiency of using these fans in different scales and in different types of blades. The parameters such as wind speed, speed of the specimen, the relationship between these speeds and loads applied to the structure of the fan were used to set a specific method for this work. It is expected a result of the use of textures to achieve proper mass distribution annular wasting energy, making the process more efficient and aesthetic rotation.