Methodology for assessing and reducing the aerodynamic imbalance of the impellers of GTE fans

Abstract

The reasons for the occurrence of increased vibration of the engine rotor due to aerodynamic imbalance of the fan of the first stage of the impeller are determined. A method for estimating the aerodynamic imbalance of the gas turbine engine fan is proposed, taking into account the influence of the following factors: geometric errors in the manufacture of blade airfoils and their positioning in the disk; deformation of the blade airfoil during the assembly of the impeller, as well as the factors of the working process occurring in the impeller. The use of the technique makes it possible to evaluate the aerodynamic imbalance of the impeller at the stage of its balancing and significantly reduce the amount of aerodynamic imbalance by determining the parameters for removing a layer of material or adding corrective masses. The influence of geometric errors of the blades on the value of the aerodynamic imbalance of the impeller was analyzed. Based on the results of the research, the type of dependence of unbalanced gas forces on the influence of technological and operational factors of the impeller under consideration was determined.

Keywords

• impeller
• aerodynamic imbalance
• unbalanced forces
• balancing
• finite element model
• geometric deflections
• operating factors
• regression dependence