Research And Numerical Simulation On Radial Dynamic Flexibility Of An Aeroengine’s Supporting System

As the heart of the aircraft, aeroengine working in poor conditions where affected by mechanical shock excitation、pneumatic shock excitation and thermal field etc leads to abnormal outstanding whole body vibration which have undesirable influences on the working statuses of accessory system and instrument system. Vibration caused by variable flexibility of the supporting system influences dynamic property of the aeroengine, varying parameter of the supporting parts have a great influence on dynamic flexibility of the supporting system. Optimal designed tolerance based on suppression of the whole body vibration can determine the only tolerance of each parameter on the basis of optimal designed parameter, and reduce the vibration response of the whole body. Testing radial dynamic flexibility of aeroengine’s supporting system and running a numerical silulation can analyze the degree of each part of aeroengine’s radial dynamic flexibility. In the view of the characteristic of a fanjet, an analysis about test method and numerical simulation are proceeded on radial flexibility of aeroengine’system based. Specific content as follows:Firstly, by building a relationship of radial load and displacement tested from multiple loaded test articles with different amplitude and frequency, a full test method about radial dynamic flexibility of aeroengine’s supporting system at the usual temperature is introduced which can studies radial dynamic flexibility of bearing、 bearing pedestal、assembly of bearing and bearing pedestal and stator of the system.Secondly, Based on the test method of radial dynamic flexibility which has been introduced, relevant testing programs are designed which contains radial dynamic flexibility test of each fulcrum’s bearing、bearing pedestal、assembly of bearing and bearing pedestal and stator of the whole body system loaded different axial force、 amplitude and frequency based on different bearing clearance、assembly clearance a locking torque.Thirdly, carry out a forecast experiment of bearing’s dynamic flexibility, put forward and use testing data extraction technology like displacement fixed、force fixed、connecting space removed etc, sort out and analyze test data then study the results, arrive at the main reason for the error, put forward effective solutions which can provide technical support for further improving and optimizing test programs.Fourthly, as a result of bits of experiment caused by time lessing, perform numerical simulations on all testing programs mentioned about supporting system of aeroengine’s whole body, come to contribution degrees of bearing or bearing pedestal in the radial dynamic flexibility test of assembly of bearing and bearing pedestal based on different assembly parameters and multiple relevant dynamic flexibility regions. Acquire radial dynamic flexibility of different sections of cartridge receiver in different directions with different parameters which can provide safeguard for comparing data with field test. Result of research shows that:Bearing plays an important role in radial dynamic flexibility of assembly of bearing and bearing pedestal. Cartridge receiver and assembly of bearing and bearing pedestal have different regulations on who has the key role in ratial dynamic flexibility. Bearing clearance and assembly clearance can mainly determine the radial dynamic flexibility. Bearing clearance can rearch 19.45%, and assembly clearance can rearch 86.78%. Change bearing clearance and reduce assembly clearance can efficiently reduce radial dynamic flexibility.Finally, run a study on radial dynamic flexibility of the whole body system in specially thermal field, make a comparative analysis on radial dynamic flexibility of bearing、bearing pedestal、assembly of bearing and bearing pedestal as well as cartridge receiver at usual temperature and at the working temperature, and analyze the effect of different temperature on radial dynamic flexibility of parts of the supporting system. The result indicates:Radial dynamic flexibility of each part of the whole body system increases with the raising temperature.