Combustion performance analysis of hydrogen-enriched methane in a custom-designed burner

Due to the increasing global energy demand and growing environmental concerns, efforts have been made to achieve optimal combustion conditions by blending hydrogen gas with conventional fuels at various ratios, taking into account the adverse combustion effects of pure hydrogen. The aim of this study is to investigate the effects of hydrogen addition—at varying concentrations and without premixing—on the flame characteristics of methane combustion within a specially designed burner. The analysis was conducted using ANSYS Fluent computational fluid dynamics (CFD) simulations, and the results were further interpreted and predicted through the application of the artificial neural network (ANN) method. In this study, combustion reactions were performed for 13 different hydrogen concentrations ranging from 0% to 30% in increments of 2.5%, blended with CH4 gas. The simulation results revealed that increasing the hydrogen concentration within the mixture led to higher flame temperatures and generally more stable flame structures. The maximum flame temperature of 2303.82 K was achieved at 30% hydrogen addition. At this concentration, the trend plateaued, indicating rich mixture behavior and a reduced rate of increase. The axial flame profile also became more uniform, with consistent distribution across the burner center. Additionally, maximum velocity values were observed to increase in correlation with rising maximum flame temperatures. As a result of the prediction analyses conducted using ANN and regression equations, the accuracy of the results was calculated, and the reliability of the CFD studies was evaluated. CFD analyses were validated by comparison with various experimental studies, and the results were found to be in agreement.