Application Of MDO To Integrated Aerodynamic/Structural Design Of Wings

Aerodynamic design is one of the most important issues in aircraft preliminary design. In thepreliminary design stage of aircraft, the integrated design of wings’ aerodynamic and structure is atypical MDO (multidisciplinary design optimization) problem of multivariate and high coupling. Onone hand, the design involves a large number of parameters of aircraft shapes, wing structural layoutsand structure properties. And on the other hand, the interdisciplinary coupling of aerodynamic andstructure is so complex that the aero elastic effects could not be ignored. The paper aims to find out apractical multidisciplinary optimization process of wing aerodynamic and structure, and develop aneffective tool for the tradeoff analysis of wings’ aerodynamic efficiency and structural weight. Takingthe preliminary design of aircraft wings as specific problem, the thesis focus on the follows:a) The integrated design problem of aerodynamic and structure was refined and defined to analyzethe interactions between the disciplines of aerodynamic and structure, and propose an effectivedecoupling scheme. Based on the two-level optimization method with surrogate model, twocomprehensive optimization strategies were put forward for considering the static aeroelasticity in theMDO problem with different couplings.b) Parameterized analysis was carried out on wing-body combination shape and wing structures,and the unified documents for all parameters involved was established, and the input files was offeredfor the auto-generation of multidisciplinary models.c) Using software collaborative technologies as CAD, CFD, CSD and so on, a program was writtenfor auto-generate multidisciplinary analysis models of high precision such as aerodynamic analysismodel based on full potential equation, the structural simulation model upon NASTRAN,interdisciplinary data transmission model applying MATLAB etc. what is more, based on all theprograms above, a numerical study on wing’s static aeroelasticity problem was conducted fast andaccurately, and a parameterized, automatic and modularized computational environment foraerodynamic/structural coupling analysis has been established as well.d) According to the wing multidisciplinary optimization scheme proposed, a detail process of wingaerodynamic and structural MDO was implemented. The computational environment of MDO was setup in the iSIGHT-FD, and the automatic analysis and stimulation of wing aerodynamic and structuralMDO were realized.e) In the two MDO environments established, taking the wing design of civil aircraft as thedemonstrative problem, multidisciplinary design of wing aerodynamic and structure was optimized both with considering and without considering the static aeroelasticity. The results were investigatedand compared. The results show that the MDO process of aerodynamic and structure proposed in thepaper in feasible, and the computational environment established is stable and efficient, which can beapplied to solve the integrated preliminary design problem of aerodynamic and structure.