Patent ID: 8375698
Filing Date: 2013-02-19
Classification: F01D,F02K,F05D,Y10T

Abstract:
1. A method for reducing the vibration levels in a turbine engine comprising a first moveable bladed disk and a second moveable bladed disk, forming a propfan of contrarotating disks, because of the turbulence of aerodynamic origin generated by the second bladed disk on the first bladed disk, said method comprising: A—defining an initial configuration of the blades as a function of an expected performance of the turbine engine, with individual aerodynamic profiles of p sections (c B—calculating, in a computer, a synchronous forced response y(ω) on the first bladed disk as a function of a harmonic excitation force f(ω) generated by the second bladed disk based on a relation y(ω)=F( C—defining, in a computer, a coefficient (α<1) of reduction of the synchronous forced response y(ω); D—determining, in a computer, for each of said p stacked sections (c E—calculating, in a computer, a synchronous forced response y′(ω) on the first bladed disk; F—if |y′(ω)|>α*|y(ω)|, repeating, in a computer, the calculation at D with new tangential geometric offset values; G—if |y′(ω)<α*|y(ω)|, manufacturing at least a portion of the blades of said one of the two disks with the new configuration and employing the blades in the propfan; and H—operating the propfan with reduced vibration levels.