- I don't know if you are referring to the "thermal-perturbations of fluid dynamics" (ie the surging from the flux in heated/cooled, pressure changes... and related fuel-flow (the flame getting larger and smaller)...
[yes some terminology, but that makes sense to me. .all depends upon the what/how the flame is created… if it is gas-regulated (ie like the “fuel-injector” controls in an engine, without that it revs and sputters… compare to a Butane/Bunsen-burner or a Welding-torch… even flame… vs a candle or a “torch” ]
anyway, I've seen swirls and bending of flame (or smoke or heat-patterns), but would be more of a difference per context.. what had it been doing? compare to just lighting it without 'use" -does it do the same, using the same equipment?