METHOD OF DETERMINING GAS TURBINE ENGINE STABLE OPERATION MARGIN Russian patent published in 2011 - IPC F04D27/02 

FIELD: engines and pumps.

SUBSTANCE: proposed method comprises creating disturbed airflow at engine intake, measuring stationary and dynamic parametres of said airflow in flight conditions, determining critical peripheral irregularity of flow Δσ_ocr in measured parametres at engine inlet and mean square deviation of turbulent pulsation intensity εor, calculating critical total flow irregularities W_or with due allowance for peripheral flow irregularity Δσ_ocr and mean square deviation of turbulent pulsation intensity εcr. Note here that in the case of engines communicated with aircraft inlet via transition element, a diffuser with opening angle not exceeding 6°, in calculating critical total flow irregularities W_cr, radial flow irregularity Δσ_rcr is allowed and defined as the difference between critical radial flow irregularity Δσ_r in flight in conditions of engine stable operation margin, and maximum radial flow irregularity Δσ_rmax in flight with normal operating conditions. Critical total flow irregularity W_cr is calculated by the formula W_cr=Δσ_ocr+ε_cr+Δσ_r, where: Δσ_ocr is critical peripheral flow irregularity; ε_cr is critical mean square deviation of turbulent pulsation deviation; Δσ_r=Δσ_r-Δσ_rmax is flow radial irregularity.

EFFECT: higher validity and accuracy of test results in determination of engine gas dynamic stability margin.

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