Published 6 issues per year
ISSN Print: 2150-766X
ISSN Online: 2150-7678
Indexed in
DIAGNOSTICS AND ACTIVE CONTROL OF ACOUSTIC INSTABILITIES IN COMBUSTORS BY ELECTRICAL DISCHARGES AND PLASMA JETS
ABSTRACT
Electro-acoustic characteristics of various acoustic oscillators operating on the basis of modulated electrical discharges are studied. The results of experimental studies of acoustic instability in model and real ram-jet and liquid-rocket combustors are presented in the form of the spectrum of the pressure-oscillation response to a harmonic perturbation generated by modulated discharges. A new promising method for active control of unstable combustion modes is developed based on the use of electrical discharges using a current- or voltage-stabilized power source. A selective sensitivity of the combustion zone to external perturbation is discovered in experiments with premixed hydrocarbon flames exposed to modulated discharges. Experiments performed in model combustors revealed that combustion instability arises when the fuel resonance coincides with the acoustic combustor resonance. The developed method and results are also applicable to propellant combustors and hybrid solid propellant chambers.