Combustion roar of premix burners, singly and in Paris

Sound pressure level data from three sizes of simple premix burners, singly and in pairs, are presented as a function of the square of the firing rate, a commonly used correlation relation, and as a function of the product of pressure drop and heat release rate. While the linear fit was only slightly better in the latter case, the new relation was directly derivable from a simple theoretical model. Furthermore, an extension of the new theory leads to a prediction of the observed peaking frequency of the spectrum of combustion roar.