Multi-level design and optimization of turbine joint structure

For the optimization design of aero-engine turbine joint structure, a 3-step optimization method was developed based on different levels and requirements: basic parameter optimization for 2-D model of joint, joint structure optimization for 3-D model with disk and multidisciplinary optimization of aerodynamics and structural strength for disk. The 3-step optimization process was iterative; in the first step, the basic parameters were built; the secondary step was established on former results, while some important parameters influencing the disk can be taken into account. When the second step cannot meet the requirements or make the best result, the multidisciplinary optimization was conducted, the outlines of turbine flow path were designed according to aerodynamics analysis, and the 3-D turbine blades were introduced. Through the multidisciplinary optimization of aerodynamic and structural strength, the optimum solution can be obtained to realize the relatively best result of the two disciplines. The results show that, after the optimization the max radial stress of the joint structure dropped by 12.7% in the first step, the mass of turbine decreased by 6.9% in the second step and the comprehensive result of aerodynamic and structural strength increased by 2.4% in the third step while meeting the requirements of design.