An Investigation Into the Control of the Combustion Instability Using Acoustic Resonator for a Jet Engine

Combustion instability in jet engines impedes efficient burning of fuel and degrades engine performance. Moreover, it can cause damage to the combustion chamber and even lead to a destructive failure in the operation of the engine. Considerable work has been carried out both theoretically and experimentally to understand the characteristics of this instability and develop control methods. These instability studies have been found based upon different on-line tests. However, they have incurred high costs and have often achieved limited results. This paper presents an acoustic method that relies on the coupling relationship between combustion and acoustics to monitor the behaviour of the instabilities. The appropriateness of using this acoustic method is confirmed by off-line experimental results. In addition, it is possible to implement the test at very low cost. Based on this investigation, a scheme has been developed to control the instabilities. It consists of a bank of resonators designed to match the resonant frequencies at which instability occurs. Test results show that this scheme produces effective suppression of the instabilities.