Dual-point design of transonic airfoils using the hybrid inverse optimization method

A new dual-point design procedure has been developed to improve the aerodynamic performance of transonic airfoils at two design points. A target pressure distribution at each design point was optimized by a genetic algorithm. Single-point design was performed to make an airfoil that produced given target pressures and satisfied specified geometric constraints at each design point. Following this, several intermediate airfoils were made by the hybrid inverse optimization method. A redesigned airfoil of dual-point design was found using the weighted average of intermediate airfoil shapes, based on the linear variation assumption. Two examples of dual-point design to improve the performance at an off-design condition are presented. These design examples show that the dual-point design procedure presented in this paper is very efficient for the multipoint design of transonic airfoils.