Method for determining a shape of a mistuned blade of an impeller of a turbomachine

A method for determining a shape of a mistuned blade of an impeller of a turbomachine, comprising the following steps:

• providing a nominal blade which has multiple radially threaded-on profile elements,
• providing an initially mistuned blade which has multiple radially threaded-on profile elements, the initially mistuned blade having a reduced or increased thickness at at least one of the profile elements compared with the nominal blade,
• determining a shape of the nominal blade in a hot state of the nominal blade,
• determining a shape of the initially mistuned blade in a hot state of the initially mistuned blade,
• comparing the two shapes determined in the hot state and determining at least one parameter of the initially mistuned blade, a value of which differs from a corresponding at least one parameter for the nominal blade in the hot state,
• changing a value of the at least one parameter of the initially mistuned blade in a cold state such that a difference between values of the at least one parameter for the initially mistuned blade and the corresponding at least one parameter for the nominal blade in the hot state no longer exists;
• wherein the provisioning of an initially mistuned blade having a reduced or increased thickness compared to the nominal blade in at least one of the profile elements comprises that the difference between a distortion energy and a kinetic energy of an excited nominal blade is determined and the thickness of the nominal blade is increased or reduced as a function of the determined difference between the distortion energy and the kinetic energy in a region under consideration.