The best method for arriving at noise levels of flares IMO is the German standard VDI 3732, which is based on measured noise levels from many elevated and ground flares, mainly in Germany. The standard is bilingual (German and English). It can be downloaded with a credit card for 56.40 Euros from :
We use FlareSim for the prediction - there's also been a couple technical papers published on general flare design and I know the noise equation was published in the papers. I'll see if I can find it.
@peteship:
I was told that VDI 3732 refers to steam assisted flares only - is that true? Otherwise I would give it a try and buy it.
@maddocks:
What are your experiences with the noise prediction of FlareSim? Are the calculations matching reality? I will get a trial copy of FlareSim.
I would appreciate if you would find the noise equation
Joo: To be perfectly honest, I've never been concerned with the noise at the peak blowdown rate of a plant. Usually this rate is connected with a major event like fire, ESD, or high gas detection - that usually captures my attention far more than thinking about flare noise.
Even a simple google search on flare noise is getting a ton of hits - do a little more digging. I'll see if I can find the missing paper this week sometime.
Maddocks: First thing I did was a lot of google search before starting this thread ... and I was scanning and reading tons of papers ... but found no useful calculations. I had discussions with experts who told me "... based on this data in my experience this flare is less than 90dB SPL" - which might be correct but not satisfying. So far no one shows up with any calculation/prediction.