A multi-point approach to airfoil shape optimization

Airfoil design is essential for civil aircraft. A multi-point method is presented in this article to improve the aerodynamic performance of airfoil over a range of the flight envelope. This method combines computational fluid dynamics and numerical optimization. It comprises of three phases: 1) Airfoil shape parameterization method to develop candidate shapes. 2) Flow solver validation to calculate aerodynamic forces. 3) Searching for the optimized airfoil shape using the genetic algorithm. The major limitation of single-point design is the poor off-design performance. By basing the objective on a combination of the drag at three design points, the resulting overall performance can be improved with respect to the single-point result.