Methods and means of research Experimental installation and measurements

Experimental installation includes the researched compressor, consisting of inlet guide vanes (IGV), rotor (R) and stator (S). The compressor has a cylindri­cal fl)wing path and is designed as a typical stage of the low-speed compressor on the following parameters: external diameter Dc = 1.2m, hub/tip ratio di­ameter d = 0.8, relative maximal airfoil thickness Cmax = 10%, frequency of the R rotation n = 2000rot/min, the R tip speed Uup = 125m/s, air fbw rate G = 30.8kg/s, ft>w coefficient ф = 0.5, loading coefficient ф = 0.32, total pressure ratio nt = 1.055, efficiency pad = 0.90, inlet and outlet ft>w angles a = a3 = 90°, a degree of reaction т = 0.8. Flowing path and measurements are shown on Fig.1.

In initial assembly the compressor has numbers of blades IGV, R and S equal, accordingly, 36, 38, 36. The construction of the compressor allows to change over a wide range axial gaps between blade rows from 5 up to 90mm (from 0.05 up to 0.93 lengths of an axial projection of the R blade) and numbers of vanes in stators. During experiment independent turn of the IGV and S is carried out, that allows to measure circumferential distortion of a flow field and their change owing to mutual shift of the stators. The IGV vanes, having a symmetric airfoil, are located along an axis of the compressor with a zero incidence angle.

At experimental researches the measurements were made, allowing to re­ceive average on time gasdynamical parameters of the compressor, and also structure of unsteady ft>w outside of and inside blade rows R and S. Unsteady values of pressure were measured with the help of high-response sensors ‘En – devco”on the R case in 6 points, on the suction and pressure surfaces S vanes in 12 points and in a ft>w behind the R and S on mean radius (see Fig.1).

Flow velocity was measured with the help of two-component laser anemome­ter (LDA) on mean radius in an axial gap between R and S.