Results of research Overall compressor parameters

On Fig.4 changes on a stators pitch of total pressure upon mean radius be­fore R and static pressure upon the case behind R, measured in axial gaps at 1-st assembly of the compressor on the design operating mode at Uup = 125m/s, ф = 0,5. Thus, in the researched compressor R blades work in conditions of the disturbed ft>w on an input owing to wakes behind the IGV vanes and on an output owing to potential influence upwards on a ft>w of the S vanes. Dis­placement on a phase of these disturbances by mutual circumferential shift of the IGV and S (changes of parameter v), is the basic source of clocking effect.

Change of the overall parameters in 1-st assembly of the compressor in de­pendence on a mutual circumferential position of stators is presented on Fig.5. Change of efficiency makes 0,8 ^ 1,0% and this change, basically, is con­nected to change of a total pressure ratio. At other assemblies of the compres­sor change of efficiency on v did not exceed 0, 5% and is commensurable with a margin error its definitions during experiment. It gives the basis to consider 1-st assembly of the compressor with identical number vanes in stator rows and with identical axial gaps Д12 = Д23 = 0,15 the optimal on clocking effect on overall characteristics of the compressor.