Mohammadsadeghi F. The detection method of pre-surge state in axial compressor using the parameters of casing vibration

Object of research- regularities, parameters and criteria that characterize the vibration of the compressor casing with its pre-surge state. Objective - prevention of the development of surge of the axial compressor by timely detection of the pre-surge state using the casing vibration. Research methods - methods of numerical modeling of stationary and nonstationary flows in channels; experimental studies of non-stationary processes in full-scale and model stages of an axial compressor; methods of spectral analysis, median and bandpass flitration. Theoretical and practical effects - on the basis of results obtained during research and method developed to detect the pre-surge state of the axial compressor, it is possible to create a system for diagnosing the pre-surge state for protecting the axial compressor from surge, which will expand the effective operation zone of the compressor and increase the reliability of the gas tubine engine protection Novelty - A new method for detecting the pre-surge state of an axial compressor is proposed, based on the analysis of the casing vibrations, which ensures the increase in the reliability of the compressor; For the first time, the vibration parameters of the compressor casing have been determined - changes in the vibration amplitudes at the surge frequencies and the frequencies of the operating blades, which are diagnostic attributes of the pre-surge state; the vibrodiagnostic method for determining the speed of movement of the zones of rotating surge in an axial compressor at non-calculated operating modes with preliminary identification of vibration signal has been further developed. Degree of implementation - the proposed method is tested at JSC "Motor Sich", and is used in the teaching of the disciplines "Diagnosis and control of aircraft and engines" and "Vibroacoustics of aircraft engines" at National Aerospace University "Kharkiv Aviation Institute". Area of application - gas turbine engine construction