Response Surface Method for Airfoil Design in Transonic Flow = 천음속 유동에서의 익형설계를 위한 반응면 기법의 비교연구

다국어 초록 (Multilingual Abstract)

Response Surface Method (RSM) applied to transonic airfoil design problem is studied with other optimization methods. The objective function and constraints of RSM are modeled by quadratic polynomials, while the response surfaces are constructed by Navier-Stokes analyses in transonic flow region. To assess the advantages of RSM, the design results by RSM are compared to those of Gradients Based Optimization Method (GBOM), namely discrete adjoint variable method. Comparisons are made for various sets of design variables and geometric constraints, It is observed that response surface method is able to capture nonlinear behavior of the objective function and smooth out high frequency noises in transonic regime. These features enable the method to design a shock free transonic airfoil with fewer design variables than in GBOM. In addition, RSM gives robust design results for the geometric constraints with different characteristics, whereas the GBOM depends heavily on the method of constraint specification. The results indicate that RSM could be used as an effective design tool for multidisciplinary design optimization problems, in which flow fields of design conditions are significantly nonlinear with many constraints imposed.

목차 (Table of Contents)

• Nomenclature
• Introduction
• Flow Analysis
• Design Objective and Variables
• Gradient Based Optimization with an Adjoint Method
• Response Surface Method(RSM)
• Results and Discussion
• Number of Design Variables
• Constraint Imposition Methods
• Conclusions
• Acknowledgement
• References