Abstract: A method for determining a shape of a mistuned blade of an impeller includes: providing a nominal blade with radially threaded-on profile elements; providing an initially mistuned blade with profile elements, the mistuned blade having a reduced or increased thickness at at least one of the profile elements compared with the nominal blade; determining the shape of the nominal blade in a hot state; determining the shape of the mistuned blade in the hot state; comparing the two shapes and determining a parameter of the mistuned blade which differs from the corresponding parameter for the nominal blade in the hot state; and changing the value of this parameter for the mistuned blade in the cold state such that the difference between the parameter for the mistuned blade and the nominal blade in the hot state no longer exists.

Abstract: A turbocharger turbine rotor includes a rotor basic body, and moving blades configured without an outer shroud. The moving blades, forming a defined curvature region, merge into the rotor basic body with a defined, constant or variable curvature radius rf. On a first group of first moving blades, the following relationship applies to the curvature radius of the curvature region of the first moving blades: 2.5%?rf1*100/l?10%, wherein rf1 is the constant or variable curvature radius of the curvature region of the first moving blades and l the length of the first moving blades on a flow trailing edge. On a second group of second moving blades, the curvature radius rf2 of the curvature region of the second moving blades deviates from the curvature radius rf1 of the curvature region of the first moving blades on the damping side in a defined manner.

Abstract: A method for selecting a mistuning pattern of a turbomachine rotor disk includes providing information items relative to boundary conditions of a rotor disk excitation by forced vibrations; providing a reduced-order model of the rotor disk; producing a multiplicity of mistuning patterns of the rotor disk by entering the information items and the reduced-order model into a multi-objective optimizer and producing the mistuning patterns by the multi-objective optimizer while optimizing stability of the system in relation to self-excited vibrations while simultaneously optimizing stability of the system relative to forced vibrations. For each mistuning pattern produced, the reduced-order model is applied to a rotor disk, which implements the produced mistuning pattern, and the properties of this rotor disk are determined in view of self-excited vibrations and in view of forced vibrations. One of the mistuning patterns is selected for implementation.