Patent ID: 8721272

Claim:
A ring diffuser for an axial turbomachine, comprising: an outer wall; an inner wall coaxial with the outer wall; and a diffuser duct between the outer wall and the inner wall extending in ring form along an axial extent so as to diverge from an inflow-side end to an outflow-side end, wherein the inner wall and the outer wall in each case comprise a wall surface delimiting the diffuser duct, a first wall surface of the inner wall and/or a second wall surface of the outer wall being rotationally asymmetrical at least in a first portion of the ring diffuser, wherein the first portion is arranged at the inflow-side end of the ring diffuser and merges into a rotationally symmetrical second portion which is arranged downstream of the rotationally asymmetrical first portion in relation to a throughflow direction of the ring diffuser, and wherein the rotational asymmetry of the first portion includes a critical axial contour which forms with the axial extent an angle, the size of which amounts to between 0° and 40° and is of different size in different axial positions of the first portion.