Non Premixed Flames
AE 6766 Project 3
Nonpremixed Flames
Introduction: In order to understand the structure of non-premixed flames, this projects employs a type of opposed flow diffusion to generate a nearly one-dimensional an axisymmetric diffusion flame. The one dimensional character of this flame is significant because it reduces complexities compared to a 2 dimensional flame, which allows for manageable and practical calculations. Moreover, this type of flame can be generated and easily investigated in the laboratory and allows for analytical and experimental comparison. That is, the one dimensionality of the flame limits measurement to the axial direction of the flame. Important parameters such as residence time can be easily varied in this flame, which underlines its suitability for studying diffusion flame structure. Understanding of laminar diffusion flames is a very important baseline for extending our understanding of turbulent flames, which makes investigation of this flame structure even more attractive. The one-dimensionality of the system is achieved through a transformations from an axisymmetric problem, which is done with the Chemkin solver. In this project we investigate the situation of a two opposing jets. One jet is fuel, the other is oxidizer. A specified distance of 1 cm separates the exit of both streams. We limit this investigation to one fuel, namely methane and one oxidizer, atmospheric air. The calculations are performed at atmospheric pressure and a prescribed reactant temperature of 533 K. A baseline jet exit velocity of 20 m/s for both jets is used. At first a basic understanding of the opposing diffusion flame structure will be developed with the baseline conditions. Variations along the axial direction will be investigated to determine flame location, stagnation points, a temperature profile and mass fractions of species. In order to explore the effect of strain rates on the flame structure we investigate a second case, where the exit jet
Nonpremixed Flames
Introduction: In order to understand the structure of non-premixed flames, this projects employs a type of opposed flow diffusion to generate a nearly one-dimensional an axisymmetric diffusion flame. The one dimensional character of this flame is significant because it reduces complexities compared to a 2 dimensional flame, which allows for manageable and practical calculations. Moreover, this type of flame can be generated and easily investigated in the laboratory and allows for analytical and experimental comparison. That is, the one dimensionality of the flame limits measurement to the axial direction of the flame. Important parameters such as residence time can be easily varied in this flame, which underlines its suitability for studying diffusion flame structure. Understanding of laminar diffusion flames is a very important baseline for extending our understanding of turbulent flames, which makes investigation of this flame structure even more attractive. The one-dimensionality of the system is achieved through a transformations from an axisymmetric problem, which is done with the Chemkin solver. In this project we investigate the situation of a two opposing jets. One jet is fuel, the other is oxidizer. A specified distance of 1 cm separates the exit of both streams. We limit this investigation to one fuel, namely methane and one oxidizer, atmospheric air. The calculations are performed at atmospheric pressure and a prescribed reactant temperature of 533 K. A baseline jet exit velocity of 20 m/s for both jets is used. At first a basic understanding of the opposing diffusion flame structure will be developed with the baseline conditions. Variations along the axial direction will be investigated to determine flame location, stagnation points, a temperature profile and mass fractions of species. In order to explore the effect of strain rates on the flame structure we investigate a second case, where the exit jet