Another, related question: how can stoves be so different? Not everything roars the same. Recently, I started playing around a bit with my old Svea 123r. It roars, but it’s nothing compared with the Primus Multifuel I had 20 yrs. ago. That one produced an unbearable eardrum-piercing shriek, a bit like an F-104 Starfighter in low level flight, but less pleasant (I grew up not far from a military airbase). I sold it to a guy planning a trip in Mongolia, and bought a Trangia.
The noise output from a stove is directly related to the velocity of the fluid being burnt. “Silent” burners have a lower flammable fluid velocity than equivalent “roarer” burners hence the lower sound output. Best Regards, Kerophile.
Hey George, Thanks for the links showing previous discussions. But my question is not the noise level comparison. Indeed silents have some noise as well. But a roarer burner really roars. It is completely different from silents. Any idea?
It is dificult to me explain in english - but ill try... At first Sound is the air pressure changes in range 30 hz to 21 khz Sources of sounds in roarer burner 1 nipple jet flowed gas 2 ignition area constant explosion of gas/oxigen 3 top of the flame or proper fluctuations on the top flame Frequency of sounds 1 high circa 5 khz 2 low circa 3 hundrets hz 3 low circa 150 hz WHAT WE HEAR source no.3 Why Power of sounds depends on pressure changes "There" changes are biggest Hard to easy say why flame is not permanently the same on every side of the burner all the time. But We must remember burning depends on triangle: Temperature -fuel - air where elents are corellated Thats give Us dynamic changes of flame haigh Extremal example of that is rocket pulsation engine Here We have 'compilatio a few not synchronus engins'
Hola! The roaring is due to Kelvin-Helmoltz instability. You basically have the hot, high-velocity exhaust flowing through the cold "stationary" air. The turbulence generated at the interface produces lots of little sound sources at the vortices, thus the "roar".
