How to analyze the length scales of vortex (eddies) in the downstream the flames using experimental data such as temperature and observations with eyes?

Thanks.

Open & close your eyes at ?regular? intervals, & you will see 'waves'. Or, use a video camera - thermal radiography may also be appropriate.

At this point, the 'eddies' may begin to take on a more obvious form. I tend to think of flames as chemo-kinetic waves.

mw...