A More Modern Theory of Combustion Noise

Some of the newer concepts that have emerged in the theory of turbulent reacting flows are applied to the problem of combustion-generated noise. A general theory is constructed for noise radiation from a turbulent combustion region in the practical limit of low frequency and low Mach number. The theory is specialized to simple cases of premixed and nonpremixed jet flames radiating to a free field. Comparison with experiment is given for premixed flames. A new interpretation is given for the frequency content of combustion noise, which is in accord with experiment.