Driving of combustor oscillations by gaseous propellant injectorsMeasurements of reactive admittances that describe the capabilities of the combustion processes associated with coaxial gaseous fuel injectors to amplify combustor oscillations are presented. These admittances are needed in (1) stability analyses of rocket motors and gas turbine combustors; (2) for the evaluation of 'driving' capabilities of injectors; and (3) for checking the applicability of a theoretical model. The modified standing-wave technique was used to determine the admittances of the combustion processes in coaxial injectors utilizing air-acetylene mixtures. The measurements indicated that (1) coaxial injectors can sustain combustion instabilities over wide frequency ranges; (2) the maximum driving capability of an injector decreases with an increased equivalence ratio; (3) the frequency at which maximum driving is observed decreases with the increased equivalence ratio; and (4) the characteristic combustion time of an injector design decreases with increased frequency.
Document ID
19800027649
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Janardan, B. A. (Georgia Inst. of Tech. Atlanta, GA, United States)
Daniel, B. R. (Georgia Inst. of Tech. Atlanta, GA, United States)
Zinn, B. T. (Georgia Institute of Technology Atlanta, Ga., United States)