ABSTRACT
Combustion in a owing turbulent fuel-air mixture is always accompanied by noise. In a gas turbine, the total noise resulting from normal combustion is often referred to as core noise. It comprises two components, (1) direct combustion noise that is generated solely by the combustion process itself, and (2) indirect combustion noise that is produced by the ow of hot combustion products through the turbine and exhaust nozzle [1]. In this chapter, we shall concentrate on direct combustion noise and also on the more insidious forms of noise that arise when combustion instabilities become coupled to acoustic modes in a combustion chamber.
