脉冲爆震涡轮发动机转子系统优化设计

Design Optimization of Rotor System in Pulse Detonation Turbine Engine

为研制某脉冲爆震涡轮发动机样机,根据总体设计要求设计了相应的空心轴转子-轴承结构系统。基于有限元法建立了该转子系统的理论分析模型,采用数值积分方法开展了考虑脉冲爆震非定常周期气动载荷作用的转子系统动力学特性计算。将在临界转速处转子的振动幅值最小化作为优化目标,以转子系统各阶临界转速与发动机慢车转速及工作转速之间的裕度作为约束条件,结合转子强度的相关要求,基于NSGA-II多目标优化算法对转子系统的支承位置、刚度及转子结构的几何参数进行了优化设计。结果表明:优化后的转子-轴承系统满足总体设计要求,临界转速与工作转速之间的裕度超过20%,且保证了前3阶临界转速对应的振动幅值最小化。研究方法和结果可为脉冲爆震涡轮发动机转子系统结构设计和优化提供参考。

In order to develop a Pulse Detonation Turbine Engine(PDTE)prototype,a hollow-shaft rotor-bearing structural system was designed based on the overall design requirements.The finite element method was employed to model the rotor system and the numeri⁃cal integration method was used to investigate the dynamic characteristics of the system under cyclic unsteady aerodynamic loads caused by pulse detonations.By taking the minimization of vibration amplitude of the rotor at critical speed as the optimization objective,treating the margins between the critical speed of the rotor system and the engine idle speed and the working speed as the constraints,and taking rele⁃vant strength requirements into account,the support position,stiffness and geometrical parameters of the rotor system were optimized based on the NSGA-II multi-objective optimization algorithm.The results show that the optimized rotor-bearing system satisfies the over⁃all requirements,the margins between the critical speeds and working speeds are over 20%,and the vibration amplitudes corresponding to the first three critical speeds are minimized.The methods and results of the present study can provide references for the structural design and optimization of the rotor system of pulse detonation turbine engines.