Numerical study on the effect of fuel jet design parameters for MILD combustion characteristics

Abstract This study investigates the characteristics of the Moderate or Intense Low-oxygen Dilution (MILD) combustion at different design parameters related to fuel port. The effect of fuel jet diameter and number of fuel ports were investigated. The current numerical study was based on a three-dimensional geometry of gaseous burner. All computations were performed using ANSYS FLUENT 19.0. Four cases for number of fuel inlets (4,8,12 and 16 mm) were studied without any change in the fuel mass flow rate. Moreover, three different values of fuel jet diameter (2,3 and 4 mm) were analyzed. It was concluded that increasing the number of fuel ports leads to enhanced mixing and significant reduction in CO and NO emissions. Smaller jet diameter enhances the mixing of diluents, leading to more complete combustion and lower combustion temperatures. The enhanced mixing leads to effective reduction on NO and CO emission.