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Made available in DSpace on 2014-12-17T14:58:10Z (GMT). No. of bitstreams: 1 FernandaAR_DISSERT.pdf: 8485678 bytes, checksum: eca5de592a0a48a71b782d8289da3a31 (MD5) Previous issue date: 2011-02-25 / The great importance in selecting the profile of an aircraft wing concerns the fact that its relevance in the performance thereof; influencing this displacement costs (fuel consumption, flight level, for example), the conditions of flight safety (response in critical condition) of the plane. The aim of this study was to examine the aerodynamic parameters that affect some types of wing profile, based on wind tunnel testing, to determine the aerodynamic efficiency of each one of them. We compared three types of planforms, chosen from considerations about the characteristics of the aircraft model. One of them has a common setup, and very common in laboratory classes to be a sort of standard aerodynamic, it is a symmetrical profile. The second profile shows a conFiguration of the concave-convex type, the third is also a concave-convex profile, but with different implementation of the second, and finally, the fourth airfoil profile has a plano-convex. Thus, three different categories are covered in profile, showing the main points of relevance to their employment. To perform the experiment used a wind tunnel-type open circuit, where we analyzed the pressure distribution across the surface of each profile. Possession of the drag polar of each wing profile can be, from the theoretical basis of this work, the aerodynamic characteristics relate to the expected performance of the experimental aircraft, thus creating a selection model with guaranteed performance aerodynamics. It is believed that the philosophy used in this dissertation research validates the results, resulting in an experimental alternative for reliable implementation of aerodynamic testing in models of planforms / A import?ncia na escolha do perfil de asa de uma aeronave ? fun??o de sua relev?ncia no seu desempenho; influenciando desde os custos de deslocamento (consumo de combust?vel, n?vel de v?o, por exemplo), a condi??es de seguran?a do v?o (resposta em condi??es cr?ticas) do avi?o. O objetivo deste trabalho foi analisar quatro perfis de asa a fim de determinar alguns dos principais par?metros envolvidos no comportamento aerodin?mico e determinar a efici?ncia de cada um deles baseado em experimenta??o em t?nel de vento. Compararam-se quatro perfis de asa, escolhidos a partir de considera??es acerca das caracter?sticas do modelo da aeronave. Um deles apresenta uma configura??o sim?trica usual, sendo muito comum em aulas de laborat?rio por ser uma esp?cie de padr?o aerodin?mico. O segundo perfil apresenta uma configura??o do tipo c?ncavo-convexo; o terceiro, tamb?m ? um perfil c?ncavo-convexo, por?m, com aplica??o distinta do segundo; e, finalmente, o quarto aerof?lio possui um perfil plano-convexo. Para a realiza??o do experimento utilizou-se um t?nel aerodin?mico do tipo circuito aberto, onde analisaram-se as distribui??es de press?o em toda a superf?cie de cada perfil. De posse da curva polar de arrasto de cada perfil de asa pode-se, a partir da base te?rica deste trabalho, relacionar as caracter?sticas aerodin?micas ? expectativa de desempenho da aeronave experimental tipo JN-1, gerando assim um modelo de sele??o com garantia de performance aerodin?mica. Acredita-se que a filosofia de pesquisa utilizada nesta disserta??o legitima os resultados obtidos, consistindo-se em uma alternativa experimental confi?vel para execu??o de testes aerodin?micos em modelos de perfis de asa

Baigiamajame magistro darbe nagrinėjamos būsimo eksperimentinio akrobatinio lėktuvo aerodinaminės savybės. Pristatomos tokio pobūdžio sritys (temos), kaip tinkamo sparno profilio parinkimas orlaiviui, reikalingo sparno formos apibrėžimas, sparno būsimos charakteristikos ir parametrų apskaičiavimas, kitų orlaivio dalių ir jų įtakos visai lėktuvo dinamikai analizavimas. Kadangi analizuojamas dvivietis eksperimentinis akrobatinis lėktuvas, tikintis geresnių rodiklių, pasirinktas palyginimo objektas  dvivietis akrobatinis mokomasis lėktuvas SU 29. Remiantis šio lėktuvo esamomis charakteristikomis ir parametrais, pateikiamos išvados ir siūlymai. / The thesis examines the aerodynamics of future experimental aerobatic aircraft. Featured in such areas (topics): proper selection of an aircraft wing profile, the required form of the wing, the wing's future performance and parameter estimation, other aircraft parts and their impact on the entire plane dynamics analysis. As analyzed double seated, experimental aerobatic plane in the hope of better indicators selected comparison object  double seated acrobatic training plane SU 29. Based on the existing aircraft characteristics and parameters, the conclusions and recommendations will be made.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-10-01T13:57:59Z No. of bitstreams: 2 Dissertação - Geovanne Silva Faria - 2018.pdf: 4034833 bytes, checksum: 3e0011bf7d9acbf63ef8baf1b0409686 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-01T14:53:53Z (GMT) No. of bitstreams: 2 Dissertação - Geovanne Silva Faria - 2018.pdf: 4034833 bytes, checksum: 3e0011bf7d9acbf63ef8baf1b0409686 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-01T14:53:53Z (GMT). No. of bitstreams: 2 Dissertação - Geovanne Silva Faria - 2018.pdf: 4034833 bytes, checksum: 3e0011bf7d9acbf63ef8baf1b0409686 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-31 / The Brazilian energy matrix is highly focused on hydroelectric plants, that have been affected by lack of rain and long drought periods. It’s necessary to invest on alternative kinds of energy. The wind energy is an option, since Brazil presents winds with suitable velocity for energy generation, less than 5% of the Brazilian energy power grid is composed by wind turbines. The present work aims to contribute to the alternative energy generation industry, having as objective the study and analysis of flow condition over airfoils of vertical axis wind turbines. The simulation of flow over airfoils were performed using the Pseudo-Spectral Fourier method together with the Immersed Boundary method for discretization of the spatial domain, and the Runge-Kutta method of fourth order for discretization of the time domain. Both instantaneous and mean values were recorded for the lift (Cl) and drag coefficient (Cd), as well as the fields of vorticity, pressure and velocity for the flow over the airfoils with distinctive characteristics of form and angle of attack. It is concluded that with this first experiment, by refining the mesh, the values for Cl and Cd get close to the references. Posteriorly, it was imposed the movement of rotation of one vertical axis wind turbine, and simulated the flow over this turbine blades, when it was recorded both the instantaneous and mean values of the lift, drag and power coefficient, as well as the fields of vorticity, pressure and velocity for different values of velocities of turbine rotation for the airfoils NACA 0008 and NACA 4308. It was possible to conclude by analyzing the values of power coefficient (Cp), Cl and Cd obtained through simulation with the turbines that the airfoil NACA 0008 can be utilized for energy generation, since the airfoil NACA 4308 cannot be utilized in the adopted speed ranges. / A matriz energética Brasileira é altamente focada em usinas hidrelétricas, que vêm sendo afetadas pela falta de chuvas e longos períodos de estiagem. É necessário o investimento em fontes energéticas alternativas. Uma das opções é a energia eólica, pois o Brasil apresenta ventos com velocidades adequadas para geração de energia e, mesmo assim, menos de 5% da matriz energética brasileira é constituída de turbinas eólicas. O presente trabalho visa contribuir com a indústria de geração de energias alternativas tendo por objetivo o estudo e análise de escoamentos sobre aerofólios de turbinas eólicas verticais. As simulações de escoamentos sobre aerofólios foram realizadas com o método Pseudoespectral de Fourier em conjunto com o método da Fronteira Imersa para discretização do domínio espacial, e o método de Runge-Kutta de quarta ordem para discretização do domínio do tempo. Foram registrados os valores instantâneos e médios dos coeficientes de sustentação (Cl) e arrasto (Cd), bem como os campos de vorticidade, pressão e velocidades para escoamento sobre aerofólios com distintas características de forma e ângulos de ataque. Conclui-se com esse primeiro experimento, que ao se refinar a malha, os valores de Cl e Cd se aproximam das referências. Posteriormente, foi imposto o movimento de rotação de uma turbina eólica de eixo vertical, e simulado o escoamento sobre as pás dessa turbina, onde foram registrados os valores instantâneos e médios dos coeficientes de sustentação, arrasto e potência, bem como os campos de vorticidade, pressão e velocidades para diferentes valores de velocidade de rotação da turbina para os aerofólios NACA 0008 e NACA 4308. Foi possível concluir ao analisar os valores de coeficiente de potência (Cp), Cl e Cd, que o aerofólio NACA 0008 pode ser utilizado para geração de energia elétrica, já o aerofólio NACA 4308 não deve ser utilizado para a faixa de velocidades adotadas.

Ventilation might seem like a minor consideration, but when properly installed, it can extend the life of the attic and roof structure of residential buildings saving huge dollar amounts in repair costs. The objectives of this study were to measure the wind effect on different kind of vents as the problem is vents are subjected to high wind loads during hurricane events and often fail causing water penetration and damage of interior contents. Wind-induced failure of rooftop vents during a hurricane may result in large openings in the roof that will allow water to penetrate into the building, a puncturing of the roof membrane, again allowing water infiltration, and detached rooftop vents can pose considerable threats as windborne debris. The study found that water infiltration through a vent system is dependent upon the differential pressure as well as the vent mechanism. For vents experiencing higher differential pressures, vent covers can be used during storms to reduce water infiltration. Active controls can also be designed to close the vents automatically as differential pressure increases based on the wind speed and wind angle of attack.

No description available.

The diploma thesis is focused on a quantification of hydrodynamic load of overflowed bridge deck. Solution was pursued by using two–dimensional numerical simulation of open channel flow in vertical plane created in ANSYS 15.0 software (modules: Workbench, Design Modeler, Meshing, Fluent). Values of drag force, lift force, moment, drag coefficient, lift coefficient and moment coefficient is result of computation. Various types of bridge decks were tested in relation to the degree of inundation (inundation ratio) and flow velocity.The thesis provides comparison of numerical simulation with physical experimental testing and result published in accessible resources.

This diploma work considers conceptual design of aircraft in accordance in FAR 103 regulation. On the base of statistical dates has been made basic geometrical and aero-dynamical concept of a single occupant aircraft. For conception have been chosen optimal driving force and bases calculations of the load pressure and dimensions are included.

No description available.

Drag polars for three Micro Air Vehicles (MAVs) were measured at Reynolds numbers of 70,000, 50,000, 30,000, and 10,000 and compared to predictions generated using the classical approach. The MAVs tested had different configurations and aspect ratios varying from 1.2 to 1.6 and ratios of wetted surface area to planform area from 2.6 to 3.9. A force balance was used to measure the lift and drag on the MAVs at angles of attack ranging from -5 degrees (or -10 degrees) to 10 degrees. The force balance allowed the MAVs to rotate in the pitching axis. The MAV angle of attack was set using an elevator installed on the MAV and controlled using a standard radio control used by RC plane enthusiasts. Uncertainty analysis performed on the data showed the uncertainty for high Reynolds numbers was dominated by velocity uncertainty, and uncertainty for the lower Reynolds numbers was dominated by uncertainty in the force measurements. Agreement between measured and predicted drag polars was good with the measured drag never being more than two times the predicted drag. For the majority of the tests, the drag coefficients followed the expected Reynolds number trend: increasing with decreasing Reynolds number.