Abstract
Combustion oscillations are excited by a feedback mechanism which results from the coupling between the flame instability and an acoustic resonance mode of the combustion chamber. The most important event of this mechanism is believed to be the upstream feedback from the acoustic resonance to the initial region of the flame, where new disturbances are generated. A control system has been implemented into a household burner to counter act this upstream feedback. This is achieved by means of pulsating either the fresh air for combustion or the fuel. The actuators are activated by the signal of a sensor measuring the pulsation inside the combustion chamber. Combustion oscillations of this burner have been eliminated altogether, without destabilising other acoustic modes, resulting in 35 dB reduction in the amplitude of pressure pulsations.
