A parametric study of microjet assisted methane/air turbulent flames. (15th May 2017)

• Record Type: Journal Article
• Authors: Chouaieb, Sirine; Kriaa, Wassim; Mhiri, Hatem; Bournot, Philippe
• Is Part Of: Energy conversion and management. Volume 140(2017)
• Page Start: 121
• Page End: 132
• Publication Date: 2017-05-15
• Subjects: Methane/air flames -- K-epsilon Standard model with Pope Correction -- Microjet -- Velocity -- Diameter -- Soot; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2017.02.079
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Microjet assisted methane/air turbulent flames are numerically investigated. A parametric study concerning the microjet velocity and diameter is carried out. Previous validation of temperature, mixture fraction and soot is enhanced. Mixing and soot emission are controlled for higher velocities and lower diameters. Soot production is reduced by 94% for a microjet velocity equal to 1 m/s. Abstract: A parametric study of microjet assisted methane/air turbulent flames characteristics is numerically investigated. The Presumed Probability Density Function model and the Discrete Ordinates model are respectively considered for combustion and radiation modeling. The k-epsilon Standard model with Pope Correction is adopted as a turbulence closure model. The two step Tesner model is used to quantify the soot particle production in the flame configuration. Comparison with our previous work using the k-epsilon Realizable model shows that the k-epsilon Standard model with Pope Correction ensures better predictions. The microjet velocity and diameter effects on thermal field, mixing process and soot emission are then discussed. Numerical findings show that the microjet can be used as an efficient tool controlling methane/air turbulent flames. On the one hand, it is shown that the microjet creates an inner flame in the vicinity of the central nozzle exit but does not globally alter the methane/air flame shape. On the other hand, mixing process can be enhanced for high microjet Reynolds number either by increasing the microjet velocity or by decreasing its nozzle diameter for a constant microjet mass flow rate. Soot production can be consequently reduced for low microjet diameter and high velocity values.