Research On Accuracy Prediction And Phase Optimization Of Aeroengine Rotor Assembly

The high-pressure compressor of aeroengine is the core part of the engine,which includes many rotor parts with similar structure.In the assembly of this part,the assembly coaxiality is the main technical evaluation index,which has an important influence on the unbalance and the performance of the whole machine during the operation of the rotor.Therefore,it is necessary to predict the assembly accuracy before rotor assembly,and adjust the assembly phase according to the prediction results,so that the coaxiality of components after assembly can reach the optimal.At present,rigid contact is generally used as the assumption in some existing calculation models of rotor assembly deviation cumulative transfer,which does not consider the contact deformation between joint surfaces,and the accuracy prediction results are not accurate.In order to solve this problem,this paper studies the Hertz contact theory of the asperity,considers the elastic deformation between the joint surfaces,establishes the elastic contact model of the rotor joint surface,and optimizes the installation phase of the rotor based on the accurate prediction of the assembly accuracy,so as to improve the assembly accuracy of the rotor.The main contents are as follows:(1)In view of the deficiency that the existing calculation model of rotor assembly deviation does not consider the contact deformation between joint surfaces,this paper first makes a practical measurement of the joint surface runout data of the high-pressure rotor simulation part,equivalent the runout measurement point to the surface asperity shape.Hertz contact is introduced to analyze the elastic contact deformation mechanism of a single asperity.Based on this,an elastic stacking contact model of the rotor interface is established,which is more suitable for the actual assembly.(2)Through the analysis of the assembly characteristics of high pressure rotor,this paper proposes a method of initial rigid contact pose prediction based on the driving of mass center,and then on the basis of it,combined with the elastic stack contact model,a method of elastic pose prediction using step-by-step iterative method is proposed to predict the assembly accuracy of components more accurately.(3)On the basis of accurate prediction of assembly accuracy,the installation phase of multi-stage rotor is optimized.Firstly,the phase optimization equation for rotor concentricity is established.By analyzing the characteristics and constraints of the optimization problem,the operation of genetic algorithm is improved and appropriate parameters are selected to optimize the phase of the measured data of a high-pressure rotor.In order to avoid the bow rotor,the coaxiality constraint is added to the optimization equation,and the installation phase is solved by an example of the algorithm.The performance of the algorithm is analyzed from the accuracy and efficiency,and the effectiveness of the optimization algorithm is verified.In addition,the integrated software is developed based on Python language,so that the prediction and optimization algorithm can be easily used in the actual assembly process.(4)The experimental scheme design and relevant data measurement of multistage rotor assembly of high-pressure under different assembly phases compressor are carried out,and then the rotor assembly finite element model with real surface morphology is established based on the measured run out data,and the elastic stacking contact model of rotor joint surface proposed in this paper is simulated and verified by experiments.Through comparison and error analysis,the relative error of the prediction results obtained by the elastic algorithm is relatively low,and the prediction accuracy is better than that of the rigid algorithm,which has a certain guiding effect on the actual assembly process of the rotor.