Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries

Detalhes bibliográficos
Autor(a) principal: Miguel, João Carlos Tavares
Data de Publicação: 2019
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10400.6/8870
Resumo: This dissertation purpose is to study the impact that a geometry modification of a wind turbine rotor imposes on its performance. The studied wooden rotor, with a diameter of 1.2 m, belongs to a family of small wind turbines that are built by unskilled persons using hand tools with the guidelines of Hugh Piggott. Due to its inaccuracy, the production process delivers a geometry with sharp leading edges. For the performance of an airfoil, the leading edge is one of the most important characteristics to take in mind, and so, the goal of this dissertation was to smooth the airfoils leading edge towards the lower surface in order to widen the ????- ?? curve of the rotor. To do so, numerical methods were employed to assess such modification on the performance, in a way that the technique could be later applied on the rotor using nothing but hand tools. In a previous investigation, the same rotor here approached in this dissertation, was numerically and experimentally studied for the following windspeeds: 3.0; 3.7; 4.4; 5.5; 7.2 e 7.7 m/s. In the same study, a digital scan was performed on the rotor, one for each blade, resulting in 6 different cross sections each with its chord and incidence angle. The three blades present geometric differences. Having these airfoils characteristics, the QBlade software was used for the design and analysis of the new modified airfoils based on the original Piggott airfoils. The software also allows for rotor design and uses the Blade Element Momentum Theory for the analysis of horizontal axis wind turbines. The performance of both rotors was approximated by averaging the performance of three ideal rotors, each consisting of three identical blades 1,2 and 3. The new airfoils regarding blade 1 and 3, presented better aerodynamic efficiency performance compared to the Piggott airfoils, whereas blade 2 new airfoils did not exhibited any significant improved performance compared to the Piggott airfoils.The dimensionless simulations results from QBlade, portrayed that the averaged rotor with the modified airfoils present better power coefficient (????) for high values of ?? (ratio between the tangential velocity of the blade tip and the free stream windspeed) when compared to the averaged rotor with the Piggott airfoils. For a constant rotational speed of 500 RPM, the new rotor remarkably withdraws more energy from the flow for low windspeeds. In a hypothetical approach of a optimized turbine production made up by the best modified airfoils, the optimized rotor simulations showed a significant better performance for high values of ??,as well as higher maximum ???? than the ones from the averaged rotor with the modified airfoils.
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spelling Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped CountriesAirfoilLeading EdgeDomínio/Área Científica::Engenharia e Tecnologia::Engenharia AeronáuticaThis dissertation purpose is to study the impact that a geometry modification of a wind turbine rotor imposes on its performance. The studied wooden rotor, with a diameter of 1.2 m, belongs to a family of small wind turbines that are built by unskilled persons using hand tools with the guidelines of Hugh Piggott. Due to its inaccuracy, the production process delivers a geometry with sharp leading edges. For the performance of an airfoil, the leading edge is one of the most important characteristics to take in mind, and so, the goal of this dissertation was to smooth the airfoils leading edge towards the lower surface in order to widen the ????- ?? curve of the rotor. To do so, numerical methods were employed to assess such modification on the performance, in a way that the technique could be later applied on the rotor using nothing but hand tools. In a previous investigation, the same rotor here approached in this dissertation, was numerically and experimentally studied for the following windspeeds: 3.0; 3.7; 4.4; 5.5; 7.2 e 7.7 m/s. In the same study, a digital scan was performed on the rotor, one for each blade, resulting in 6 different cross sections each with its chord and incidence angle. The three blades present geometric differences. Having these airfoils characteristics, the QBlade software was used for the design and analysis of the new modified airfoils based on the original Piggott airfoils. The software also allows for rotor design and uses the Blade Element Momentum Theory for the analysis of horizontal axis wind turbines. The performance of both rotors was approximated by averaging the performance of three ideal rotors, each consisting of three identical blades 1,2 and 3. The new airfoils regarding blade 1 and 3, presented better aerodynamic efficiency performance compared to the Piggott airfoils, whereas blade 2 new airfoils did not exhibited any significant improved performance compared to the Piggott airfoils.The dimensionless simulations results from QBlade, portrayed that the averaged rotor with the modified airfoils present better power coefficient (????) for high values of ?? (ratio between the tangential velocity of the blade tip and the free stream windspeed) when compared to the averaged rotor with the Piggott airfoils. For a constant rotational speed of 500 RPM, the new rotor remarkably withdraws more energy from the flow for low windspeeds. In a hypothetical approach of a optimized turbine production made up by the best modified airfoils, the optimized rotor simulations showed a significant better performance for high values of ??,as well as higher maximum ???? than the ones from the averaged rotor with the modified airfoils.O objectivo da presente investigação é estudar a influência que uma modificação na geometria do rotor de uma turbina eólica inflige na sua eficiência. O rotor estudado, de madeira e com um diâmetro de 1,20 m, pertence a um grupo de pequenas turbinas eólicas que são construídas apenas com recurso a ferramentas manuais seguindo as indicações do Hugh Piggott. Este processo de construcção, devido à sua imprecisão, resulta numa geometria que dá origem a um bordo de ataque aguçado. Sendo que o bordo de ataque é um aspecto importante para o desempenho do mesmo, o objectivo desta dissertação passou por suavizar o bordo de ataque do perfil alar a “fugir” para o intradorso, de maneira a ampliar a curva ????- ?? do rotor. Para tal, recorreu-se a métodos numéricos para avaliar o desempenho de tal modificação, numa perspectiva que esta técnica possa ser aplicada no rotor usando ferramentas manuais, como por exemplo uma lixa. Num estudo prévio, o mesmo rotor que é estudado nesta dissertação foi alvo de um estudo numérico e experimental para as seguintes velocidades de vento: 3.0; 3.7; 4.4; 5.5; 7.2 e 7.7 m/s. No mesmo estudo o rotor foi alvo de uma digitalização na qual, cada pá do rotor foi examinada em 6 secções diferentes e que resultou em 6 perfis alares diferentes com a respectiva corda e o ângulo de incidência, sendo de realçar que as três pás apresentam diferenças geométricas entre si. Tendo estas características, usou-se o software QBlade para o desenho e análise dos novos perfis alares modificados a partir dos originais perfis alares do Piggott. O software permite o desenho de rotores e para a simulação do desempenho de turbinas eólicas de eixo horizontal, o software emprega a Blade Element Momentum Theory. O desempenho real do rotor original e do novo rotor foi estimado a partir da média de três rotores ideais, cada um constituído por três pás idênticas 1, 2 e 3. Os novos perfis alares das pás 1 e 3 revelaram melhor desempenho da sua eficiência aerodinâmica (????/????) quando comparados aos perfis oriundos da construção manual do Hugh Piggott, enquanto que os novos perfis da pá 2 não ilustraram qualquer melhoria significativa quando comparados aos perfis originais. Os resultados das simulações adimensionais do QBlade, mostraram que o rotor médio com os novos perfis apresenta melhor coeficiente de potência (????) para altos valores de ?? (razão entre a velocidade tangencial da ponta da pá e a velocidade do vento) quando comparado ao rotor médio com os perfis do Piggott. Quando submetidos a uma velocidade rotacional constante de 500 RPM, o novo rotor retira notavelmente mais energia do escoamento a baixas velocidades de vento. Numa abordagem hipotética da construcção de uma turbina optimizada composta pelos melhores perfis modificados, as simulações do rotor optimizado ilustraram um significativo melhor desempenho a altos valores de ?? como ???? máximos mais elevados do que os do rotor médio com os perfis modificados.Silvestre, Miguel Ângelo RodriguesMonteiro, João Manuel Milheiro Caldas PaivauBibliorumMiguel, João Carlos Tavares2020-01-28T17:06:57Z2019-07-172019-06-242019-07-17T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10400.6/8870TID:202368173enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-12-15T09:49:14Zoai:ubibliorum.ubi.pt:10400.6/8870Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T00:49:09.150004Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
title Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
spellingShingle Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
Miguel, João Carlos Tavares
Airfoil
Leading Edge
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica
title_short Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
title_full Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
title_fullStr Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
title_full_unstemmed Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
title_sort Airfoil Improvement on Horizontal Axis Wind Turbine Suitable for Local Construction in Underdeveloped Countries
author Miguel, João Carlos Tavares
author_facet Miguel, João Carlos Tavares
author_role author
dc.contributor.none.fl_str_mv Silvestre, Miguel Ângelo Rodrigues
Monteiro, João Manuel Milheiro Caldas Paiva
uBibliorum
dc.contributor.author.fl_str_mv Miguel, João Carlos Tavares
dc.subject.por.fl_str_mv Airfoil
Leading Edge
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica
topic Airfoil
Leading Edge
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica
description This dissertation purpose is to study the impact that a geometry modification of a wind turbine rotor imposes on its performance. The studied wooden rotor, with a diameter of 1.2 m, belongs to a family of small wind turbines that are built by unskilled persons using hand tools with the guidelines of Hugh Piggott. Due to its inaccuracy, the production process delivers a geometry with sharp leading edges. For the performance of an airfoil, the leading edge is one of the most important characteristics to take in mind, and so, the goal of this dissertation was to smooth the airfoils leading edge towards the lower surface in order to widen the ????- ?? curve of the rotor. To do so, numerical methods were employed to assess such modification on the performance, in a way that the technique could be later applied on the rotor using nothing but hand tools. In a previous investigation, the same rotor here approached in this dissertation, was numerically and experimentally studied for the following windspeeds: 3.0; 3.7; 4.4; 5.5; 7.2 e 7.7 m/s. In the same study, a digital scan was performed on the rotor, one for each blade, resulting in 6 different cross sections each with its chord and incidence angle. The three blades present geometric differences. Having these airfoils characteristics, the QBlade software was used for the design and analysis of the new modified airfoils based on the original Piggott airfoils. The software also allows for rotor design and uses the Blade Element Momentum Theory for the analysis of horizontal axis wind turbines. The performance of both rotors was approximated by averaging the performance of three ideal rotors, each consisting of three identical blades 1,2 and 3. The new airfoils regarding blade 1 and 3, presented better aerodynamic efficiency performance compared to the Piggott airfoils, whereas blade 2 new airfoils did not exhibited any significant improved performance compared to the Piggott airfoils.The dimensionless simulations results from QBlade, portrayed that the averaged rotor with the modified airfoils present better power coefficient (????) for high values of ?? (ratio between the tangential velocity of the blade tip and the free stream windspeed) when compared to the averaged rotor with the Piggott airfoils. For a constant rotational speed of 500 RPM, the new rotor remarkably withdraws more energy from the flow for low windspeeds. In a hypothetical approach of a optimized turbine production made up by the best modified airfoils, the optimized rotor simulations showed a significant better performance for high values of ??,as well as higher maximum ???? than the ones from the averaged rotor with the modified airfoils.
publishDate 2019
dc.date.none.fl_str_mv 2019-07-17
2019-06-24
2019-07-17T00:00:00Z
2020-01-28T17:06:57Z
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instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
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repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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