기류 조건에 따른 한국형 유리온실 지붕의 풍압계수 분포 특성에 관한 연구 = Wind Pressure Distribution on Korean-style Glass Greenhouse Roofs according to Wind Flow Characteristics

다국어 초록 (Multilingual Abstract)

This study aims to quantitatively analyze the effects of wind characteristics and roof geometries on the wind pressure distribution of Korean-style glass greenhouses through wind tunnel experiments. Despite the increasing demand for large-scale advanced greenhouses in Korea, the current Korean Design Standard (KDS) has limitations in reflecting the wind pressure distribution for the Main Wind Force Resisting Systems (MWFRS) of complex multi-span roofs and the dynamic effects of turbulence on low-rise structures.
Accordingly, 1/50 scale rigid models of wide-span and Venlo-type greenhouses were fabricated, and Boundary Layer Wind Tunnel (BLWT) tests were conducted. To simulate actual installation environments, three exposure categories(B, C, and D) were established, with a uniform flow condition used as a control to analyze the impact of wind flow characteristics on roof wind pressure. The analysis investigated frequency-domain characteristics through wind pressure mapping and Power Spectral Density (PSD) analysis. Furthermore, Computational Fluid Dynamics (CFD) was employed to visualize airflow patterns, validating the experimental results and ensuring data reliability.
The experimental results indicated that turbulence intensity, directly linked to exposure categories, is a dominant factor in determining peak negative external pressure coefficients for Components and Cladding (C&C) design. Under Exposure Category B(urban areas) with high turbulence, peak negative pressures at the roof corners were maximized due to instantaneous gusts, increasing the risk of localized damage. In contrast, under uniform flow conditions, while the peak magnitudes decreased, the tributary area subjected to maximum negative pressure expanded significantly along the roof surface. This suggests that structural preparedness against sustained suction over large areas is essential even in open terrains, emphasizing the need to consider site-specific wind characteristics in design.
Moreover, the roof geometry was found to be a primary factor in determining the concentration and distribution patterns of wind loads. Wide-span greenhouses exhibited distinct airflow acceleration and reattachment, resulting in suction zones extending deep into the roof interior. Conversely, in Venlo-type greenhouses, the dense roof valleys interrupted the airflow, preventing the load from spreading and causing it to concentrate locally near the corners and eaves. These findings underscore the necessity of differentiating load tributary areas based on roof geometry. In particular, the MWFRS analysis revealed that wind loads on the internal spans of wide-span multi-span greenhouses are equivalent to those on the external spans. Therefore, conventional load reductions for internal spans should be avoided, and structural reinforcement comparable to external spans is required.
In conclusion, ensuring the structural safety of glass greenhouses requires a differentiated design approach considering exposure categories, turbulence characteristics, and roof geometry. The results of this study will serve as a critical engineering foundation for establishing a practical wind load estimation system for Korean-style greenhouses and provide essential baseline data for developing design guidelines that prioritize wind resistance and safety.

목차 (Table of Contents)

• 1 서론 1
• 1.1 연구 배경 및 목적 1
• 1.2 연구 범위 및 내용 4
• 2 이론적 배경 및 기존 연구 동향 8
• 2.1 이론적 배경 8
• 2.2 기존 연구 동향 10
• 3 풍동실험 개요 및 방법 12
• 3.1 경계층 풍동실험 장치 12
• 3.2 기류의 동적 특성 및 재현 15
• 3.2.1 대기 경계층의 재현 16
• 3.2.2 균등류(Uniform Flow) 조건의 형성 21
• 3.3 실험 모형 및 설치 23
• 3.3.1 실험 모형 제원 23
• 3.3.2 모형 배치 및 실험 전경 28
• 3.4 측정 시스템 및 방법 31
• 3.4.1 풍속 및 풍압 측정 장치 31
• 3.4.2 실험 조건 및 방법 34
• 4 풍압계수 산정 및 분석 36
• 4.1 주골조 설계용 외압계수 특성 37
• 4.1.1 지표면 조도 변화에 따른 분포 특성 37
• 4.1.2 난류강도에 따른 외압계수 비교 53
• 4.2 외장재 설계용 피크외압계수 99
• 4.2.1 지표면 조도구분에 따른 피크외압계수 100
• 4.2.2 난류강도에 따른 피크외압계수 비교122
• 4.3 건축구조기준(KDS)과 실험 결과와의 비교 및 분석 166
• 4.3.1 주골조설계용 외압계수 비교 분석 166
• 5 난류강도에 따른 기류 특성 분석 174
• 5.1 변동 풍압의 스펙트럼(PSD) 분석 174
• 5.1.1 취약부의 피크외압계수 특성 분석 174
• 5.1.2 난류강도에 따른 에너지 스펙트럼 분석 180
• 5.2 전산유체해석(CFD)을 통한 기류 특성 분석 194
• 5.2.1 해석 개요 및 조건 194
• 5.2.2 해석 결과 및 분석 199
• 6 결론 228