CFD analysis of the combustion of hydrogen fuel on a CFM56-3 combustor

• Autor(a) principal: Domingues, Rafael Silva
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/13035
• topic: Camara de Combustão; Cfm56-3; Combustível de Aviação; Emissões de Poluentes; Hidrogénio; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

In this work is presented an overview of the use of hydrogen in aviation, the modifications needed to adapt an existing gas turbine to use hydrogen, and a CFD simulation of an existing gas turbine burning this fuel. The CFD simulation was done in a CFM56-3 combustor model burning hydrogen and Jet A (as a reference standard). It was intended to evaluate the viability of conversion of existing gas turbines to hydrogen, from a combustion point of view, by analyzing the emissions while burning this fuel through ICAO's LTO cycle. The software ANSYS Fluent 2020R2 was used to perform the numerical study and the viscous and radiation models used were the RSM and P-1, respectively. Only the NOx emissions were assessed as pollutant once the hydrogen combustion products are reduced to water vapor and NOx. These emissions were evaluated through a detailed mechanism and the NOx model available on ANSYS Fluent 2020R2 to get a better agreement with the ICAO’s values. For this assessment, several sensibility studies were also made for hydrogen burn to analyze the influence of some parameters in the pollutant emissions, for example, the analysis of the airflow with or without swirl effect in the primary zone and different inlet temperature and pressure for fuel. In the end, it was concluded that theoretically the CFM56-3 combustor can be converted to operate with hydrogen fuel with minor changes (related with the injection system). However, the quantity of NOx produced for each power setting when burning hydrogen is expected to be almost twice the values obtained for Jet A. Regarding the sensibility tests, only the changes in the swirl effect and the fuel temperature produced relevant changes in the results.