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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2014, Vol. 35 ›› Issue (3): 674-686.doi: 10.7527/S1000-6893.2013.0383

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Discrete Adjoint Optimization Method for 3D Unstructured Grid

LI Bin1, DENG Youqi1, TANG Jing1, LV Hongying2   

  1. 1. Computational Aerodynamic Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China;
    2. Xi'an Advanced Control Technology Institute, Xi'an 710065, China
  • Received:2013-05-06 Revised:2013-09-06 Online:2014-03-25 Published:2013-09-17

Abstract:

Because solving adjoint equation does not depend on the number of design variables, there is no relationship between the calculation amount of iterative optimization and the number of design variables. Based on the unstructured grid, a discrete adjoint solver is developed for a 3D Reynolds-averaged Navier-Stokes solver. Free-form deformation (FFD) technology is implemented to modify the mesh. Discrete adjoint equation can be acquired directly by formula derivation method and solved through LU-SGS iteration. The adjoint code is verified by comparing flux Jacobian and objective function gradient with finite differences. The design system is successfully applied to ONERA M6 wing transonic shape optimization design with the purpose of reducing drag, and the influence of volume constraint is also studied in this paper. It shows that the optimization method established is effective with a better application prospect.

Key words: Navier-Stokes equation, unstructured grid, aerodynamic shape optimization, discrete adjoint, LU-SGS method

CLC Number: