Development of an opposed piston geared hypocycloid engine

• Autor(a) principal: Nunes, Alexandre José Rosa
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/7914
• topic: Ciclo de Otto; Ignição Por Faísca (Si); Motor Biela-Manivela (Sce); Motor Com Engrenagem Hipocicloidal (Ghe); Motor de Combustão Interna (Ice); Motor de Pistões Opostos (Ope); Quatro-Tempos (4s); Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

The conventional slider crank engine has dominated the industry with very few alternative configurations having commercial success. In aircraft applications where engine balancing is critical to reduce vibrations, boxer engines have been developed to reduce this issue. The rising cost of fuel and awareness of pollutant emissions has led to an increased interest in alternative designs where both opposed piston and geared hypocycloid engines present some advantages over the conventional slider crank engine. In this study, a comparison between an opposed piston slider crank and geared hypocycloid engine was made followed by the design of a proposed opposed piston geared hypocycloid engine to be used in aircraft applications. It was found that the performance of the geared hypocycloid engine was similar to that of the slider crank engine in all performance characteristics considered in this study, even when excluding the mechanical losses due to friction of the piston head against the cylinder. Therefore, when considering the potential reduced losses due to friction, the geared hypocycloid engine should achieve higher efficiency. It was also found that the design of an engine is a complex task that is usually done from experience and empirical relations with a lot of practical work needing to be done to better design and describe an engine’s performance. However, this study did not include any practical testing.