ACOUSTIC METHOD AND HARDWARE-SOFTWARE COMPLEX OF OPERATIONAL DIAGNOSTICS PRE-STAGE STATE OF GAS TURBINES ENGINES BASED ON INVARIANTS RANDOM PROCESS

Abstract

One of the reasons for the early decommissioning of gas turbine engines (before the specified resources and service life are depleted) is the occurrence of unstable operating modes, namely surge. Surge is a violation of the stable operation of gas turbine engines, due to the occurrence of longitudinal self-oscillations of the flow in the entire airgas path of the gas turbine engine, resulting from the loss of dynamic stability of the flow, accompanied by a sharp drop in thrust and powerful vibration that can destroy the engine. An acoustic method for diagnosing the presurge state of gas turbine engines has been developed, based on an assessment of the change in the distribution of the amplitudes of a vibroacoustic signal, which is characterized by the use of an invariant characterizing the normal distribution of random variables, which makes it possible to quickly assess the presurge state regardless of the type, size and history of engine operation, which makes this method universal. The use of the developed acoustic method for determining the presurge state of gas turbine engines makes it possible to avoid the need for noise filtering, which at the present stage of development of presurge condition diagnostics systems based on vibration analysis plays a huge role. To implement the developed acoustic method, a hardware-software complex was created. The antisurge system can be used in automatic mode by installing hazardous and critically dangerous zones in the program for informative parameters and invariants characterizing the occurrence of surge.