导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2021, Vol. 42 ›› Issue (9): 625732-625732.doi: 10.7527/S1000-6893.2021.25732

• Special Topic of NNW Progress and Application • Previous Articles     Next Articles

Advances in viscous adaptive Cartesian grid methodology of NNW Project

CHEN Hao1,2, YUAN Xianxu1,2, WANG Tiantian3, ZHOU Dan3, ZHAO Ning4, TANG Zhigong2, BI Lin1,2   

  1. 1. State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang 621000, China;
    2. Computational Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China;
    3. Key Laboratory of Rail Traffic Safety, Ministry of Education, School of Traffic and Transportation Engineering, Central South University, Changsha 410075, China;
    4. College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
  • Received:2021-03-30 Revised:2021-04-28 Published:2021-05-26
  • Supported by:
    National Numerical Windtunnel Project; State Key Laboratory of Aerodynamics Foundation(SKLA-2019-12)

Abstract: Compared with traditional structured and unstructured grids, the Cartesian grid has the advantages of automation and high quality, and therefore is an important development direction of grid technology in the future. Relying on the National Numerical Windtunnel (NNW) Project basic research system, this paper studies viscous adaptive Cartesian grid methodology, focusing on the grid generation technology, adaptation method, and viscous wall boundary treatment method, for the development of Cartesian mesh generation software. For the grid generation technology, optimization of the quadtree or octree data structure is conducted, starting from optimization of the Cartesian grid data structure and based on the idea of the fully thread tree data structure; a more stable K-dimensional tree method compared to the traditional one is constructed aiming at the information search of facets. For the determination of grid types, the painting method and axis aligned bounding box method are developed to improve the efficiency, and a high-performance parallel computing technology based on message passing interface is developed for large-scale grids. In the aspect of adaptation technology, an adaptation method based on geometric features and flow field solution features is developed, the flow field structure capture criteria established, and the application of three-dimensional complex configuration carried out; to reduce the scale of global mesh, the anisotropic adaptive method is developed, and the comprehensive criteria for anisotropic feature recognition constructed; the normal ray refinement technology is developed to reduce the number of grids in the boundary layer. In the aspect of wall boundary processing, the overset Cartesian grid method is developed, and the overset grid scale matching technology and data interaction method constructed. Meanwhile, the adaptive application of the wall function method in the Cartesian grid framework is carried out to relax the size limitation of the wall grid and reduce the number of boundary layer grids, and finally the reliability of the method is verified by typical examples.

Key words: Cartesian grid, National Numerical Windtunnel (NNW) Project, data structure, adaptation method, wall boundary treatment

CLC Number: