The Investigation Of Dynamic Characteristics And Balance Technology Of A High Speed Flexible Rotor Of Aeroengine

Rotor is an important component of aeroengine.A new type contra rotating engine is a turbofan engine with two rotor.The engine exhaust with inside and outside bypass and low bypass ratio.The specified operating speed of the low pressure rotor is high and length-to-diameter ratio of the rotor is large,so specified operating speed is over the first three bending critical speed.Rotor is rather sensitive to unbalance,vibration caused by unbalance of rotor is an important cause of whole engine vibration,therefore,high speed dynamic balance must be finished before it is used in engine and balance is extraordinary difficulty.Based on the need of investigation, a simulating low pressure rotor is designed and machined. This paper lucubrate the dynamic characteristics and high speed dynamic balance investigation of the simulating low pressure rotor,main purpose is to establish base for the dynamic characteristics and high speed dynamic balance investigation of the real low pressure rotor and solve a key technique during model development,focal point is experiment investigation.The main contents of this paper are following:(1)Being aimed at the structure characteristics of simulating low pressure rotor,such as large length-to-diameter ratio and with elastic support and squeeze film damper,finite element calculation model is set up in order to calculate dynamiccharacteristics of simulating low pressure rotor.The dynamic characteristics of the rotor, such as critical speeds,vibration modes and steady unbalance responses,are systematically calculated and analyzed respectively.(2)The experiment investigation of dynamic characteristics of simulating low pressure rotor are carried out on high speed rotating test rig,the experiment results verify the correction of calculation model.(3)The investigation of high speed dynamic balance technique of simulating low pressure rotor is accomplished on high speed rotating test rig.A multispeed, multiplane, balance step by step influence coefficient method and balance collars technics method is adopt during balance.High speed dynamic balance technology of flexible rotor which operates over the first three bending critical speed is breached,and acquire very ideal balance purpose.The balance judgement criteria (balance judgement bases) are put forward.These will supply reference and base for the dynamic characteristics and high speed dynamic balance of real low pressure rotor,and establish base for solving a technology difficulty of high speed dynamic balance during model development at last.