Is the sound from a chimney fire the same as the sound caused by a fire inside a fireplace?

Question

For a while now I've been researching the causes of why a fireplace fire makes a roaring sound, and from what I've read, it mostly has to do with the way air rises, creating a vacuum underneath, pulling cold air into it. These exchanges in air flow can disturb its surrounding environments, causing vibrations that we might be able to hear as a roar. The moisture trapped in the wood is what gives it a crackle.

What I'm wondering, however, is whether this same roaring sound is heard if there is a chimney fire, caused by the ignition of creosote and other residue in the inner tiles, flue liners, or stove pipes. Most articles I've read say that they have a distinct sound as though a train were passing by, the sound of an oncoming car, or a large bonfire. If this is true, then there should be no difference in how they sound, since fire in a fireplace and fire in a chimney should ideally create the same sound.

Unless there's something I'm not getting, can someone explain how that might be different from each other? Thanks!

Answer 1

You say

Unless there's something I'm not getting

The fire lit in the wide volume of the fireplace has different boundary conditions then the chimney. The geometry and volume of the fireplace determine the frequencies coming from a lit fire. The cylinder frequencies that are due to the geometry of the pipes may be excited by a fire in the fireplace. The fireplace frequencies cannot be excited by a chimney fire, because it does not ignite a fire in the fireplace.

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