Aero-acoustic cartography as nondestructive method for turbomachine rotor blade monitoring based on fiber optic sensors localized at a nozzle cross section

Abstract

The article is about gas air stream modeling at a nozzle cross section of a turbomachine for steady and unsteady operating mode, the mathematical model is assigned, which describes acoustic processes in a turbomachine flow path and the ways of their improvement. The principles of aero-acoustic cartography complex systems creation are defined by means of acouto-electronic and they are accompanied by methods and means of gas dynamic stream parameter measurement in the flow path and at nozzle cross section of a turbomachine. The principles described make the control more informative and ease the algorithm creation for nondestructive method of rotor blade condition monitoring. Altogether it provides reliable data in conditions of gas air stream parametric and structural uncertainty both in controlled inside section of the flow path and in outlet section at a turbomachine cut. The tasks of monitoring point placement and the tasks of a field spatial distribution reconstruction are reviewed according to measurements in a discrete set of points separately. In complex approach the turbomachine acoustic field reconstruction is realized according to measurement data of optical fiber sensor outlet using the statistical approach only. The field reconstruction in 1D, 2D and 3D formats is presented as continuous functions of spatial coordinates according to measurements in a discrete set of points where a priori information about the field features is available.