Patent ID: 8262340

Claim:
A turbomachine comprising: at least one rotor; at least one stator; a hub; a casing, the hub and casing confining a flow through the rotor and the stator to the inside and to the outside; running-gap adjacent surfaces on at least one of the hub and the casing directly opposite and facing a free end of a blade row, a plurality of separate independent openings positioned on and along a blade row free end facing circumference of at least one of the running-gap adjacent hub and casing surfaces which form a plurality of dynamically operating supply points, each of the separate independent openings directly facing, and opening independently of one another to, the free end of the blade row, with centroids of the separate independent openings being spaced from each other by an integer multiple of a blade spacing at the free end of a respective blade row, and all of the separate independent openings being arranged such that they have a dynamic pressure synchronous with one another and a blade passing frequency; the separate independent openings each having a circumferential length of significantly less than one half of one rotor blade pitch; at least one opening on a blade-passage confining surface; and at least one line connecting the dynamically operating supply points to the at least one opening on the blade-passage confining surface.