导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2015, Vol. 36 ›› Issue (2): 449-461.doi: 10.7527/S1000-6893.2014.0059

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Airfoil optimization based on improved CST parametric method and transition model

WANG Xun, CAI Jinsheng, QU Kun, LIU Chuanzhen   

  1. School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2014-03-04 Revised:2014-04-14 Online:2015-02-15 Published:2014-05-01

Abstract:

In this paper, B-spline basis function is implemented in class and shape transformation (CST) parameterization method in place of the traditional Bezier polynomials to enhance the local ability of control and accuracy to represent an airfoil shape. To guarantee the requirements on geometric smoothing performance and proper orthogonal decomposition (POD) reconstruction accuracy in airfoil design optimization process, the local fairing method for multi-resolution airfoil is proposed based on the wavelet decomposition technique, expanding the design space. A surrogate model based on POD method and γ-Reθt transition predicting model is adopted to achieve fast and accurate prediction of aerodynamic forces and transition. The computed results of flow around airfoils show that the combined surrogate model is an effective method in design optimization of natural laminar airfoil. A complete aerodynamic design optimization system for natural laminar airfoil is constructed by integrating genetic algorithm, the improved CST parameterization method with wavelet decomposition fairing, POD surrogate model and γ-Reθt transition model. The system is used for the design optimization of low-speed and transonic airfoils, achieving an increase in lift-drag ratio of 47.42% and 45.85%, respectively, which validates the efficiency of the design optimization system proposed in this paper.

Key words: airfoil, aerodynamic design optimization, transition flow, proper orthogonal decomposition, wavelet decomposition, parameterization

CLC Number: