Spatio-frequential optical measurements of acoustic sources in a turbulent flame

摘要

Several authors have shown that production of acoustic waves by turbulent flames is dependant on the structure of the combustion region [1,2]. This fact clearly appears in an aerothermoacoustic model for computation of sound radiated by turbulentcombustion under study. It consists in a statistical approach where flame structure formally appears in a spatio-frequential coherence function. Because of the lack of knowledge regarding source terms organisation, an experimental work is conducted inorder to collect information such as spatial and frequential coherence scales. First of all, the fact that reaction rate is the main origin of combustion noise is recovered. Spatio-frequential distribution of this quantity is next examined and the datascollected are injected in the aerothermoacoustic model. Then computation of sound power spectrum can be effected.