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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2018, Vol. 39 ›› Issue (1): 121415-121415.doi: 10.7527/S1000-6893.2017.121415

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Gradient calculation method of unstructured mixed grids for improving drag prediction accuracy

ZHANG Peihong, ZHANG Yaobing, ZHOU Guiyu, CHEN Jiangtao, DENG Youqi   

  1. Computational Aerodynamic Institute, China Aerodynamic Research and Development Center, Mianyang 621000, China
  • Received:2017-05-15 Revised:2017-07-12 Online:2018-01-15 Published:2018-01-15
  • Supported by:
    National Natural Science Foundation of China (11532016)

Abstract: Based on the characteristics of the unstructured hybrid grid, a new gradient calculation method named node-based Green-Gauss is presented by improving the original Green-Gauss method. To validate the new method, a numerical simulation of the DLR-F4 wing-body configuration is performed. The numerical results are analyzed and compared with that of the original Green-Gauss method. The results indicate that better residual convergence and more order of magnitude decrease can be obtained with the new method, the drag coefficients show a good agreement with experiment results, and the pressure distributions in the shock wave and separation region can be computed more accurately. It is found that the new method has excellent drag prediction accuracy and more robustness. Moreover, the Common Research Model (CRM) adopted in the 5th AIAA Drag Prediction Workshop is studied by using the method proposed. The results demonstrate that the new method is much more suitable for computation of viscosity of the unstructured hybrid grid, and the accuracy reaches the same level of famous CFD software. All of this further verify the drag prediction accuracy of the new method.

Key words: hybrid grid, drag prediction, gradient calculation, DLR-F4 wing-body configuration, Common Research Model

CLC Number: