Aeroacoustic study of a slotted burner

Slotted burner is an interesting application in the field of combustion research. In fact, this simple test case produces a two-dimensional laminar premixed flame, useful for understanding. In laboratory scale burner, it was observed that the tonal acoustic excitation of the flame changes the flame topology, the velocity and radical OH concentration field.1,2 Kartheekeyan et al.3 observed that tonal pressure fluctuation induces asymmetry and oscillations in the laminar flame front generated by slotted burner (SB). For this reason, during the design stage of a SB, an aeroacoustic study is of primary importance. Hence, in the present research, wall pressure fluctuations generated within a slotted burner have been studied experimentally for several mass flow rates. Wall pressure fluctuations have been measured through wall mounted microphones, providing single and multi-variate pressure statistics both in the time and in the Fourier domain. Furthermore the use of the wavelet based auto-conditioning permitted us to detect the signatures embedded into the pressure fluctuations. Finally in order to give an interpretation of the pressure signals, acoustic and aerodynamic investigations have been carried out as well. The analysis of the acoustic response of the slotted burner has been conducted numerically, whereas the aerodynamic study has been carried out by means of RANS simulation.