New experimental setup for thermoacoustic instabilities investigation in two-phase flow swirled combustion

Abstract : An original experimental setup is designed to study thermoacoustic instabilities in two-phase swirled-flow combustion (air/n-heptane). It is composed of an atmospheric linear multi-injection cavity whose length is adjustable in order to excite resonant chamber acoustic modes by means of an acoustic forcing. Without combustion, a procedure based on experimental, numerical and theoretical results, proposes criteria which show evidence of the presence of the 2T1L mode. Thanks to these criteria the 2T1L mode is revealed with combustion despite of the non-uniform temperature field and non-constant sound speed. The system is validated by quantifying the flame CH* emission submitted to the 2T1L mode.