Shroud having elevations, for a turbomachine compressor

Axial-flow turbomachine compressor, comprising:

• a rotor rotating around an axis;
• a stator having an annular row of vanes, each vane comprising:
• a leading edge;
• a trailing edge;
• a pressure surface;
• and
• a suction surface extending from the leading edge to the trailing edge;
• and
• a between-vanes passage with a connecting surface that links the pressure surface of a first vane to the suction surface of a second vane of the row, the connecting surface being delimited by four corners located at the leading edges and the trailing edges of the first and second vanes;
• wherein the connecting surface consists of:
• a main protuberance, the main protuberance comprising:
• a first elevation having a first peak;
• and
• a second elevation having a second peak;
• an upstream zone arranged upstream of the main protuberance and a downstream zone arranged downstream of the main protuberance, said upstream and downstream zones each being of constant radius RC from the axis;
• wherein the main protuberance forms one radial increase in material extending from the pressure surface of the first vane to the suction surface of the second vane such that all the points of a curve of shortest length linking the first peak to the second peak are radially at a distance to the axis that is greater than the constant radius RC of the upstream and downstream zones.