Pulsejet Engine Performance Estimation

• Autor(a) principal: Melo, Andreia Sofia Moura
• 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/10400.6/8866
• topic: Ansys Fluent; Caudal Mássico de Combustível; Dimensionamento; Metano; Propano; Pulsejet; Pulsejet Sem Válvulas; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

Pulsejet engines have recently come into the spotlight due to its simplicity and its possible application in UAVs. Even though this type of engine has many advantages over the conventional types, it still has many problems for its application, as in civil aviation due to its extreme noise. Although having a very simple construction, its operation is not completely understood, so studies continue to be made in order to have a better knowledge of the physics behind its operation. This work investigates a valveless pulsejet operation in a numerical approach. The objective includes a sizing of a valveless pulsejet and analyse the pulsejet performance with two different fuels and for different fuel mass flows. For the sizing it was done a calculation procedure based on data of existing engines and equation reported in the literature. The pulsejet was designed using the software CATIA V5; numerical mesh was created in ANSYS Meshing; and the analysis in ANSYS Fluent 16.2. It was performed a 2D transient simulation. The viscous model is Realizable ??-??, for species non-premixed combustion model was selected and radiation model is P1. Inlet was defined as a pressure inlet and outlet as a pressure outlet, fuel inlet was defined as mass flow inlet with three different fuel flow to be analysed: 0.04 kg/s, 0.06 kg/s and 0.1 kg/s. Two fuel where used: propane and methane, in order to evaluate whether the differences reported for the different fuel mass flow were also observed with other fuels. For propane an additional case was defined, being the fuel mass flow of 0.12 kg/s. Diverse variables were computed for the seven cases: pressure, temperature, frequency, velocity, thrust and formation of pollutants. The results obtained are similiter for the two fuels, the variables have the same behaviour with the variation of the fuel flow except for the operating frequency. For methane the frequency increases with increasing fuel flow, for propane, however, this is not verified. In the relation to the sizing, this was elaborated as a function of the desire thrust of 6 kg, nevertheless the maximum thrust obtained was of 2.5 kg.