Method for reducing the vibration levels of a propfan of contrarotating bladed disks of a turbine engine

A method for reducing the vibration levels, in a turbine engine comprising two bladed disks forming a propfan of contrarotating disks, when the two disks are traversed by a gaseous fluid, turbulence of aerodynamic origin is generated by one disk on the other. During the design of the bladed disks an initial configuration 2 of the blades is defined, the synchronous forced response is calculated 3 on the first bladed disk as a function of the harmonic excitation force generated by the second bladed disk expressed in the form of a linear function of the generalized aerodynamic force for the mode in question; for stacked sections of one of the two disks, a tangential geometric offset value of the individual aerodynamic profile is determined so as to reduce the term corresponding to the generalized aerodynamic force. The combination of the individual profiles on the sections with the tangential offsets defines a new configuration of the blades of one disk which is then applied 7.