Application of Lagrangian probability density function approach to a turbulent jet diffusion flame

Abstract

The application of the transported probability density function method in conjunction with a Lagrangian particle technique to predict turbulent reacting flows is presented in this paper. The calculation method is based upon the modelled form of the evolution equation for the joint pdf of the species mass fractions. The velocity field and the turbulence properties are obtained via a conventional gradient diffusion model (k-ε). Molecular mixing is modelled using LMSE and coalescence dispersion mixing models. Chemical reaction is described by the four-step global hydrocarbon mechanism of Jones and Lindstedt. Stochastic particle methods are used to solve the multi-dimensional pdf equations. In this work, a Lagrangian particle technique is adopted in which the pdf is represented by an ensemble of particles whose positions are tracked as they move through the solution domain.

The aim of the work is to apply transported pdf approach to turbulent reacting flows using a Lagrangian particle technique to solve the pdf transport equation. This technique will be applied on preliminary test problems and on a turbulent jet diffusion flame. Results are compared with measurements.

Keywords:

• transported probability density function
• Lagrangian particle technique
• turbulent reacting flows
• pdf
• gradient diffusion model
• LMSE
• coalescence dispersion
• global hydrocarbon mechanism
• turbulent jet diffusion flame

Acknowledgement

This work was done at the Departments of Chemical Engineering and Mechanical Engineering of Imperial College, London

Notes

¹Laser Induced Fluorescence.