초록 ▼

­ 본 연구에서는 각 개발 과정별 스마트 무인기 기체구조 모델에 대해 공탄성 및 진동해석 기법을 정립하고 관련 전산해석을 수행하였다.­ CRW형 무인기 모델에 대해 동적 플랩운동을 고려한 카나드의 3차원 공탄석 해석기법을 연구하였으며, 압축성 효과를 고려한 플러터 해석을 수행하여 관련 설계벼수가 안정성에 미치는 영향을 파악하였다.­ 스마트 무인기의 하중해석을 위해 공력해석 데이터를 3차원 구조해석 요소로 전환하기 위한 수치 보간 체계를 구축하였으며 관련 연구업무를 수행하였다.­ 3차원 모델에 대해 고유진동, 주파수응답, 천이응답해석

­ 본 연구에서는 각 개발 과정별 스마트 무인기 기체구조 모델에 대해 공탄성 및 진동해석 기법을 정립하고 관련 전산해석을 수행하였다.­ CRW형 무인기 모델에 대해 동적 플랩운동을 고려한 카나드의 3차원 공탄석 해석기법을 연구하였으며, 압축성 효과를 고려한 플러터 해석을 수행하여 관련 설계벼수가 안정성에 미치는 영향을 파악하였다.­ 스마트 무인기의 하중해석을 위해 공력해석 데이터를 3차원 구조해석 요소로 전환하기 위한 수치 보간 체계를 구축하였으며 관련 연구업무를 수행하였다.­ 3차원 모델에 대해 고유진동, 주파수응답, 천이응답해석 및 플러터해석 체계를 구축하였으며, 관련 전산해석을 수행하여 특성을 고찰하였다.­ 로터-낫셀 시스템에 대한 효과적인 휠플러터(wgirl flutter) 해석기법을 연구하였으며. 해석프로그램을 개발하였다. 개발된 해석 프로그램을 활용하여 주요 설계변수가 휠플러터 안정성에 미치는 영향을 파악하였다.

Abstract ▼

1. In this study, dynamic aeroelastic analyses of the canard with oscillating flap are conducted considering the effect of aerodynamic compressibility. The canard model considered herein is an all-movable type with a pitching axis on a canard-rotor-wing aircraft which was considered as one of the ma

1. In this study, dynamic aeroelastic analyses of the canard with oscillating flap are conducted considering the effect of aerodynamic compressibility. The canard model considered herein is an all-movable type with a pitching axis on a canard-rotor-wing aircraft which was considered as one of the major DAV candidates under developing in Korea. The equivalent structural model is constructed based on the initial design data by the Korea smart DAV development center. Both the frequency and the time-domain aeroelastic analyses have been applied to practically conduct parametric studies on the effects of equivalent torsional stiffness. In the case of all-movable control surface with oscillating flap, the equivalent rotational stiffness of the pitch axes are important design parameters. The parametric results for the aeroelastic instability are practically presented.2. Vibration and aeroelastic analyses of a T-tail have been conducted. The structural dynamic computations of the T-tail are performed using MSC/NASTRAN and CFD-based computational aeroelastic analysis method is used to investigate the complex flutter phenomena. The results for vibration and aeroelastic analyses in the frequency and time domains are presented. It is importantly shown that the modal coupling of the torsional mode of vertical-tail and the asymmetric bending mode of horizontal-tail parts can give sensitive effects for the flutter stability of T -tail configurations.3. Structural vibration analyses of a composite smart unmanned aerial vehicle (DAV) have been conducted considering dynamic hub-loads of tilt-rotor. Practical computational structural dynamics technique based on the finite element method is applied using MSC/NASTRAN. The present smart UAV(TR-S2) structural model is constructed as full 3D configurations with both the helicopter flight mode and the airplane flight mode. Modal based transient response and frequency response analyses are used to efficiently investigate vibration characteristics of structure and installed electronic equipments. It is typically shown that the helicopter flight mode with the 90-deg tilting angle is the most critical case for the induced vibration of installed electronic equipments in the front body of SUAV model.4. Subsonic flutter analyses have been conducted for a composite smart UAV with T -tail configuration at the critical flight condition. Detailed three-dimensional finite element model for dynamic analysis is constructed including its nonstructural elements corresponding to installed electronic equipments and fuels. Computational structural dynamics and aeroelastic techniques are conducted using both MSC/NASTRAN and developed in-house codes. The results for fundamental vibration characteristics and flutter instabilities are presented and compared to each other for different fuel conditions.5. Simplified whirl flutter analyses using quasisteady aerodynamic theory have been performed for a 2-DOF tilt-rotor system with both pitch and yaw motions of a rotor-nacelle. The present dynamic system consists of the rotor (propeller), forming the gyroscopic and aerodynamic element, supported horizontally by a pylon that is pivoted at some wing attachment point. Several design parameters for rotor-nacelle system are considered and the effect of whirl flutter stability are also investigated for various design parameters.