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Conceção e projeto de balança para túnel de vento
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 10.22 MB | Adobe PDF |
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Abstract(s)
Com o rápido avanço tecnológico nas indústrias aeronáutica e automóvel, a utilização de túneis de vento tem assumido um papel cada vez mais relevante na previsão e otimização do comportamento de corpos em movimento no seio de um fluido. Embora estes túneis sejam tradicionalmente utilizados para visualizar o escoamento do ar ao redor dos corpos em estudo, a integração de uma balança permite quantificar diretamente as forças aerodinâmicas envolvidas, abrindo caminho à otimização geométrica de modelos segundo objetivos
específicos. Neste contexto, a presente dissertação teve como principal objetivo o desenvolvimento de uma balança de três eixos adaptada a túneis de vento académicos, capaz de medir com precisão a força de sustentação, a força de arrasto aerodinâmico e o momento de cabragem. Após uma revisão abrangente da literatura disponível em bases de dados científicas reconhecidas, foi concluído que, tendo em conta as restrições físicas e funcionais do projeto, a solução mais adequada consistiria numa balança exterior de plataforma equipada com três células de carga, duas para medição de forças ortogonais e uma dedicada à leitura do
momento de cabragem. O processo de dimensionamento e projeto considerou as condições operacionais previstas para um túnel de vento em desenvolvimento nas instalações do Instituto Superior de Engenharia do Porto (ISEP), incluindo estimativas das cargas que serão aplicadas às células de carga e critérios de desacoplamento estrutural entre os eixos de medição. O sistema foi posteriormente construído com uma arquitetura modular, de baixo custo e de simples operação recorrendo a interfaces digitais, permitindo leituras em tempo real e configuração de alarmes. Ensaios preliminares demonstraram coerência entre os dados obtidos, embora se tenham verificado discrepâncias face aos valores teóricos, atribuídas à influência de forças de
atrito. Conclui-se que os objetivos definidos foram atingidos com sucesso, sendo a solução proposta robusta, funcional e adequada ao meio académico, com potencial de melhoria futura através da substituição de componentes poliméricos por componentes metálicos para aumentar a rigidez e prevenir a deformação não intencional dos elementos estruturais.
With rapid technological advances in the aeronautical and automotive industries, the use of wind tunnels has taken on an increasingly important role in predicting and optimising the behaviour of moving bodies within a fluid. Although these tunnels are traditionally used to visualise the airflow around the bodies under study, the integration of a balance allows the aerodynamic forces involved to be quantified directly, paving the way for the geometric optimisation of models according to specific objectives. In this context, the main objective of this dissertation was to develop a three-axis balance adapted to academic wind tunnels, capable of accurately measuring lift force, aerodynamic drag force, and pitching moment. After a comprehensive review of the literature available in recognised scientific databases, it was concluded that, taking into account the physical and functional constraints of the project, the most appropriate solution would be an external platform balance equipped with three load cells, two for measuring orthogonal forces and one dedicated to measuring the pitching moment. The sizing and design process considered the operating conditions expected for a wind tunnel under development at the facilities of the Instituto Superior de Engenharia do Porto (ISEP), including estimates of the loads that will be applied to the load cells and criteria for structural decoupling between the measurement axes. The system was subsequently built with a modular, low-cost and simple-to-operate architecture using digital interfaces, allowing realtime readings and alarm configuration. Preliminary tests demonstrated consistency between the data obtained, although there were discrepancies with the theoretical values, attributed to the influence of friction forces. It is concluded that the defined objectives were successfully achieved, with the proposed solution being robust, functional and suitable for the academic environment, with potential for future improvement by replacing polymeric components with metallic components to increase stiffness and prevent unintended deformation of structural elements.
With rapid technological advances in the aeronautical and automotive industries, the use of wind tunnels has taken on an increasingly important role in predicting and optimising the behaviour of moving bodies within a fluid. Although these tunnels are traditionally used to visualise the airflow around the bodies under study, the integration of a balance allows the aerodynamic forces involved to be quantified directly, paving the way for the geometric optimisation of models according to specific objectives. In this context, the main objective of this dissertation was to develop a three-axis balance adapted to academic wind tunnels, capable of accurately measuring lift force, aerodynamic drag force, and pitching moment. After a comprehensive review of the literature available in recognised scientific databases, it was concluded that, taking into account the physical and functional constraints of the project, the most appropriate solution would be an external platform balance equipped with three load cells, two for measuring orthogonal forces and one dedicated to measuring the pitching moment. The sizing and design process considered the operating conditions expected for a wind tunnel under development at the facilities of the Instituto Superior de Engenharia do Porto (ISEP), including estimates of the loads that will be applied to the load cells and criteria for structural decoupling between the measurement axes. The system was subsequently built with a modular, low-cost and simple-to-operate architecture using digital interfaces, allowing realtime readings and alarm configuration. Preliminary tests demonstrated consistency between the data obtained, although there were discrepancies with the theoretical values, attributed to the influence of friction forces. It is concluded that the defined objectives were successfully achieved, with the proposed solution being robust, functional and suitable for the academic environment, with potential for future improvement by replacing polymeric components with metallic components to increase stiffness and prevent unintended deformation of structural elements.
Description
Keywords
Exterior Scales Interior Scales Load Cells Wind Tunnel Aerodynamic Forces Balança aerodinâmica Células de carga Túnel de vento Forças aerodinâmicas