Study Of Effects Of Temperature Field On Aeroengine Rotor System Dynamic Characteristics

Aeroengine is one kind of heat engine, and affected greatly by temperature, material property of engine structure changes because of the nonuniform distribution of temperature especially when the working condition changes, in that case the vibration characteristics of engine should be taken seriously. To solve this problem, this paper accesses some basic methods of the thermal-structural coupling problem through vibration characteristics analysis on turbine blades of aeroengine under temperature field at first, then carries on some analysis of thermal-structural coupling on rotor system of aeroengine with these methods.It’s necessary to consider the problem of simplification before modeling of such a complicated model as rotor system of aeroengine. In this paper, the actual model is analyzed and simplified under the principle that ensures the accuracy of calculation and some of the procedure are verified, the accuracy of grid has a great effect on the veracity of solution with FEM, manual meshing of ANSA is adopted in the meshing process of main computational model.The data file of distribution of temperature is obtained through thermal analysis with boundary condition of steady-state temperature field at first place in this paper, it also takes place of the boundary condition of steady-state temperature field as thermal load during thermal-structural sequential analysis. Data files of main material parameters and complete basic processing of variable parameters with temperature during the software application process. Analysis of dynamics characteristic of rotor system under temperature field based on the above work is carried out, the results show that the influence of thermal field on dynamics characteristic of rotor system is obvious. In some special area such as turbine blade, the influence of thermal field on computational natural frequency is nearly 30%. Speed of high pressure rotor and low pressure rotor can respectively reach 1.78%, 2.78% and 5.94 %, 1.78% in first two orders, in theoretical verification that shaft segment under temperature, the influence on critical speed of low pressure rotor can respectively reach 10.24%, 5.65% and 20.24 %, 9.41% in first two orders, which shows temperature is a nonignorable and important parameters during the analysis of rotor dynamic characteristics.The methods used in this paper work well and can be used to other aeroengines. The calculation result is reasonable, which has some reference value for rotor dynamic characteristic analysis of other engines.