Qt 개발환경을 이용한 주익 Lofting 최적화 통합 프로그램 개발 = Development and Application of Wing Lofting and Shape Optimization Program using Qt Development Environment

다국어 초록 (Multilingual Abstract)

In this paper development of shape optimization program for three-dimensional wing lofting is described. This Program could be used as an useful and convenient tool for research engineering work in several fields because it offers fundamental and essential functions for data pre/post processing and user-friendly environment based on GUI. The program represents user-specified wing sections by approximating them with NURBS curves for each section, and the overall wing surface is approximately represented by interpolating those sectional NURBS curves in the span-wise direction. By using this approximate representation of wing shape, surface waviness in the span-wise direction from root to tip can be quantified and mathematically analyzed. Discontinuity of curvatures and severe waviness of wing surface can be monitored and improved by moving those control points of sectional NURBS curves. After the lofting process, the NURBS-based surface data is seamlessly used to generate 3D volume grid system for CFD analysis of lofted wing shape. Although the program still needs some improvement for user-convenience and shape approximation accuracy, it has shown the possibility of developing a wing-lofting program which can be customized to satisfy users’ requirements, and further research to extend its functionality and improve its accuracy will be pursued.

목차 (Table of Contents)

• 1. 서론 1
• 1.1. 연구 배경 1
• 1.2. 관련 연구 동향 2
• 1.3. 연구 범위 및 방법 4
• 2. 이론적 배경 6
• 2.1. 일반적인 로프팅 6
• 2.1.1. 선형내삽에 의한 날개 airfoil의 layout 7
• 2.1.2. Flat wrap 내삽에 의한 날개 airfoil layout 8
• 2.2. CATIA를 이용한 Wing Lofting 10
• 2.3. NURBS에 의한 형상정의 14
• 2.4. Approximation 18
• 2.4.1. Newton-Raphson method 18
• 2.4.2. Optimization 22
• 2.5. 곡선상의 격자점 분포 방법 23
• 2.5.1. 모서리 격자점 분포 기법 23
• 2.5.2. 대수적 기법 24
• 2.5.3. 타원형 기법 26
• 2.5.4. 쌍곡형(전진형) MAP 기법 28
• 2.6. GUI 개발 환경으로서 Qt의 특징 31
• 3. Wing Lofting 최적화 및 격자 생성 프로그램 33
• 3.1. Wing Lofting 최적화 프로그램 33
• 3.1.1. 기본적인 NURBS curve 34
• 3.1.2. 날개 planform을 구성하기 위해 적용 가능한 파라미터 35
• 3.2. 날개 체적격자 생성 프로그램 37
• 4. Wing Lofting 형상 최적화 40
• 4.1. 2D 최적화 40
• 4.1.1. DAE 11 42
• 4.1.2. NACA 2412 44
• 4.1.3. RAE 2822 45
• 4.2. 3D 최적화 45
• 4.2.1. Linear method 46
• 4.2.2. Curved method 48
• 4.3. 격자 생성 51
• 4.4. 유동해석 51
• 4.5. 최적화 결과 및 한계점 52
• 5. 결론 54
• 참고문헌 56
• ABSTRACT 57