Stochastic Numerical Simulation of a Turbulent Inverse Diffusion Flame Generated by a CAP-type Burner

ABSTRACT

A stochastic model is used to simulate the combustion process in a turbulent inverse diffusion flame (IDF) composed of a laminar diffusive flame and a premixed turbulent flame. In addition, the influence of the turbulence intensity at the outlet of the air injection nozzle was analyzed with this model. The IDF consists of one central air injection and 12 peripheral butane injections. The interaction between the aerodynamics and the thermochemical is implemented by a transport equation for a joint probability density function (PDF). For the chemical kinetic, two different global chemical reaction schemes are used: the first consists of a one-step reaction and the second involves a two-step reaction. The numerical solution of the aerodynamic is found via the finite volume method, and a cell-based Monte–Carlo particle method is used for the transport equation of the joint PDF. The numerical results are compared with experimental data.. The comparison between both global chemical reaction schemes qualitatively represents the thermal structure of the flame. Nevertheless, the two-step reaction demonstrated good accuracy for the temperature distribution of the flame, so the two-step reaction was used to analyze the behavior of the flame. The results show the increase of turbulence intensity does not modify the thermal structure of the IDF, but the dimension and temperature distribution of the flame present significant changes with an increase in the turbulence intensity.

KEYWORDS:

• Combustion
• butane
• inverse diffusion flame
• numerical simulation
• PDF

Acknowledgments

This work has been supported by (1) the CONACyT and (2) UNAM-PAPIIT IG101018. The authors would like to thank Fernando Maldonado, who is the engineer and manager of the Tonatiuh Cluster of the Instituto de Ingenieria of the Universidad Nacional Autonoma de Mexico, and his team: ASUL.

Additional information

Funding

This work was supported by the Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México [IG101018];Consejo Nacional de Ciencia y Tecnología [378312].