BALANCED INVERSE-DIRECT DESIGN OF AIRFOIL VIA MULTI-OBJECTIVE OPTIMIZATION

• Main Author: Rahmad, Yodefia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42393
• Institution: Institut Teknologi Bandung

This study follows the implementation of a balanced inverse-direct design of airfoil via multi-objective optimization. The aim of such case is to minimize the mean absolute error (MAE) of the pressure distribution compared to a given target along with a second objective of minimizing coecient of drag (Cd). The term balanced comes from the pursue of a set of non-dominated solutions where each member proposes dierent trade-o for each objective. Two dierent gradient-free optimization methods are applied: genetic algorithm (GA) and Bayesian optimiza- tion. GA mimics genetic inheritance and natural selection in nding an optimized solution through population regenerations. Bayesian optimization utilizes a Krig- ing surrogate function in modeling the objective function probabilistically based on a set of initial samples. From a total of three cases, the rst one examines the validity of the framework by optimizing NACA 0012 airfoil with a known target airfoil of NACA 2412. The second uses NLF(1)-0115 as baseline airfoil and sets the target to maintain a laminar ow over the upper surface region. The last case prescribes a reduced shock pressure distribution as the target for a transonic airfoil RAE 2822. All of the problems conducted result in a solution set which includes new airfoil congurations with acceptable quantity of error in pressure distribution compared to the target assigned and notably lower drag.