Computational Fluid Dynamics Laboratory
Localized Extinction/Reignition in Turbulent Diffusion Flame
This work is progressing toward a simulation of Sandia Flame D, E, and F
to study the dynamics of localized flame extinction and reignition, for
the purposes of developing extinction models for common engineering use.
The large eddy simulation (LES) technique is used along with the filtered
mass density function (FMDF) scalar closure model which solves for
the sub-grid scalar joint PDF, allowing accurate representation of
the highly-nonlinear combustion kinetics. A 16-species reduced chemical
mechanism is used along with a custom implementation of the in situ
adaptive tabulation (ISAT) dynamic lookup table for accelerating
chemistry calculations by several orders of magnitude.
Below is an animation of an early isothermal mixing simulation using the
FMDF closure model. The movie begins by visualizing vortical structures
in the flow along with contours of mixture fraction. The camera
then zooms into the near-field region to show the sub-grid stochastic
particles in a single plane of grid cells through the jet centerline.
It is these particles from which the resolved scales are derived.
Below are some animations of an early reacting simulation of Sandia
Flame D. These show the beginning of a simulation, where the
initially-laminar flow transitions to turbulence and combustion
begins. Mass fraction and volumetric mass production rate are
shown for a few select chemical species.
Prof. Frankel's MAIN PAGE