• 신재생에너지
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• 제17권4호
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• pp.1-8
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• 2021

To determine the wind turbine class in the offshore of the Korean Peninsula, the reference wind speed for a 50-y return period at the hub height of a wind turbine was estimated using the reanalysis data sets. The most recent reanalysis data, ERA5, showed the highest correlation coefficient (R) of 0.82 with the wind speed measured by the Southwest offshore meteorological tower. However, most of the reanaysis data sets except CFSR underestimated the annual maximum wind speed. The gust factor of converting the 1 h-average into the 10 min-average wind speed was 1.03, which is the same as the WMO reference, using several meteorological towers and lidar measurements. Because the period, frequency, and path of typhoons invading the Korean Peninsula has been changing owing to the climate effect, significant differences occurred in the estimation of the extreme wind speed. Depending on the past data period and length, the extreme wind speed differed by more than 30% and the extreme wind speed decreased as the data period became longer. Finally, a reference wind speed map around the Korean Peninsula was drawn using the data of the last 10 years at the general hub-height of 100 m above the sea level.

• Wind and Structures
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• 제37권4호
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• pp.315-329
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• 2023

We investigated the wind characteristics in the near-surface layer during the landfall of Typhoon Mujigae (2015) based on observations from wind towers in the coastal areas of Guandong province. Typhoon Mujigae made landfall in this region from 01:00 UTC to 10:00 UTC on October 4, 2015. In the region influenced by the eyewall of the tropical cyclone, the horizontal wind speed was characterized by a double peak, the wind direction changed by >180°, the vertical wind speed increased by three to four times, and the angle of attack increased significantly to a maximum of 7°, exceeding the recommended values in current design criteria. The vertical wind profile may not conform to a power law distribution in the near-surface layer in the region impacted by the eyewall and spiral rainband. The gust factors were relatively dispersed when the horizontal wind speed was small and tended to a smaller value and became more stable with an increase in the horizontal wind speed. The variation in the gust factors was the combined result of the height, wind direction, and circulation systems of the tropical cyclone. The turbulence intensity and the downwind turbulence energy spectrum both increased notably in the eyewall and spiral rainband and no longer satisfied the assumption of isotropy in the inertial subrange and the -5/3 law. This result was more significant in the eyewall area than in the spiral rainband. These results provide a reference for forecasting tropical cyclones, wind-resistant design, and hazard prevention in coastal areas of China to reduce the damage caused by high winds induced by tropical cyclones.

• 한국풍공학회지
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• 제22권4호
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• pp.171-177
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• 2018

본 연구에서는 해상 풍력용 기상탑의 파단 원인을 찾기 위하여 실측된 풍속 자료를 분석하고, 변동 풍하중과 파랑하중에 의한 동적 변위를 산정하였으며, 와류진동에 대한 피로 검토를 수행하였다. 그 결과를 보면, 베인 풍속계와 초음파 풍속계의 10분 최대 풍속을 비교하여 기상탑에서 4시간 지속된 진동이 발생했음을 확인하였다. 그리고 파랑하중보다 풍하중이 기상탑의 동적 응답에 미치는 영향이 훨씬 크지만, 두 하중이 동시에 작용해도 기상탑의 부재력이 설계력보다 훨씬 낮아서 직접적인 파단의 원인이 아닌 것으로 나타났다. 하지만 와류진동은 연결부 볼트에서 피로 파괴를 일으키는 것으로 나타나서, 기상탑의 파단 원인은 유체의 변동 성분이 아닌 와류진동인 것으로 판단된다.

• 한국환경과학회지
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• 제28권4호
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• pp.441-454
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• 2019

The present study analyzes the characteristics of 43 typhoons that affected the Korean Peninsula between 2002 and 2015. The analysis was based on 3-second gust measurements, which is the maximum wind speed relevant for typhoon disaster prevention, using a typhoon disaster prevention model. And the distribution and characteristics of the 3-second gusts of four typhoons, RUSA, MAEMI, KOMPASU, and BOLAVEN that caused great damage, were also analyzed. The analysis show that between May and October during which typhoons affected the Korean Peninsula, the month with the highest frequency was August(13 times), followed by July and September with 12 occurrences each. Furthermore, the 3-second gust was strongest at 21.2 m/s in September, followed by 19.6 m/s in August. These results show that the Korean Peninsula was most frequently affected by typhoons in August and September, and the 3-second gusts were also the strongest during these two months. Typhoons MAEMI and KOMPASU showed distribution of strong 3-second gusts in the right area of the typhoon path, whereas typhoons RUSA and BOLAVEN showed strong 3-second gusts over the entire Korean Peninsula. Moreover, 3-second gusts amount of the ratio of 0.7 % in case of RUSA, 0.8 % at MAEMI, 3.3 % at KOMPASU, and 21.8 % at BOLAVEN showed as "very strong", based on the typhoon intensity classification criteria of the Korea Meteorological Administration. Based on the results of this study, a database was built with the frequencies of the monthly typhoons and 3-second gust data for all typhoons that affected the Korean Peninsula, which could be used as the basic data for developing a typhoon disaster prevention system.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2010년도 정기 학술대회
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• pp.488-491
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• 2010

본 논문에서는 돌풍응답경감제어 효과 검증을 위한 풍동시험에 사용될 유연날개에 대해 공탄성 모델, 조종면 작동기 모델, 돌풍 모델 등으로 구성되는 서보공탄성 모델링을 수행하였으며, 이에 대한 연속돌풍 응답해석을 수행하여 상용 Solver를 이용한 해석결과와 비교하여 구성된 서보공탄성 모델을 검증하였다. 또한, 유연날개의 돌풍응답을 경감하는 조종면 제어기를 설계하고, 이에 대한 수치 시뮬레이션을 수행하여 돌풍응답 경감효과를 검증하였다.

• 한국방재안전학회논문집
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• 제6권2호
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• pp.1-8
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• 2013

우리나라 전체 재해 60%이상인 태풍과 같은 바람재난으로부터 구조물이나 외장재가 안전과 사용성 측면에서 설계되려면 내풍설계과정에서 기본풍속, 설계속도압, 풍하중 등 많은 파라미터들이 요구된다. 본 논문에서는 최근 2003년부터 2012년까지의 10년 동안 년최대풍속이 발생한 날의 풍속으로부터 확률과정과 확률분포, 통계적 성질 등을 알아보기 위하여 8개의 대표지점을 여수, 인천, 서울, 청주, 원주, 대구, 속초, 울릉도로 선정했다. 선정된 각 지점에 대한 최근 10년 동안의 풍속자료는 기상청으로부터 획득했다. 각 지점의 획득한 풍속자료는 우리나라를 직접 통과하면서 영향을 미친 태풍과 통과는 안했지만 간접 영향을 미친 태풍, 년최대순간풍속과 년최대평균퐁속이 같은 날 등을 고려 90개의 앙상블 중 선별된 33개의 모집단에 대한 풍속자료의 확률과정 및 확률분포의 특성을 비교 검토하였다.

• Wind and Structures
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• 제34권2호
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• pp.231-257
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• 2022

Transmission lines systems are important components of the electrical power infrastructure. However, these systems are vulnerable to damage from high wind events such as hurricanes. This study presents the results from a 1:50 scale aeroelastic model of a multi-span transmission lines system subjected to simulated hurricane winds. The transmission lines system considered in this study consists of three lattice towers, four spans of conductors and two end-frames. The aeroelastic tests were conducted at the NSF NHERI Wall of Wind Experimental Facility (WOW EF) at the Florida International University (FIU). A horizontal distortion scaling technique was used in order to fit the entire model on the WOW turntable. The system was tested at various wind speeds ranging from 35 m/s to 78 m/s (equivalent full-scale speeds) for varying wind directions. A system identification (SID) technique was used to evaluate experimental-based along-wind aerodynamic damping coefficients and compare with their theoretical counterparts. Comparisons were done for two aeroelastic models: (i) a self-supported lattice tower, and (ii) a multi-span transmission lines system. A buffeting analysis was conducted to estimate the response of the conductors and compare it to measured experimental values. The responses of the single lattice tower and the multi-span transmission lines system were compared. The coupling effects seem to drastically change the aerodynamic damping of the system, compared to the single lattice tower case. The estimation of the drag forces on the conductors are in good agreement with their experimental counterparts. The incorporation of the change in turbulence intensity along the height of the towers appears to better estimate the response of the transmission tower, in comparison with previous methods which assumed constant turbulence intensity. Dynamic amplification factors and gust effect factors were computed, and comparisons were made with code specific values. The resonance contribution is shown to reach a maximum of 18% and 30% of the peak response of the stand-alone tower and entire system, respectively.

• 한국태양에너지학회 논문집
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• 제27권1호
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• pp.1-9
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• 2007

This paper reveals both the operational situation and the cause of the error occurred in wind turbine generator system of Hangwon wind farm in Jeju island. The four wind turbines were selected for this work, and the monitored period was for six months. Wind resource in the wind farm was analyzed, and the estimated energy production was compared with the actual energy production. As a result, with a decrease of system error, the estimated energy production was in good agreement with the actual energy production. The errors occurring in components such as gearbox and hydraulic motor affected the Availability of the wind turbine. Also, poor external conditions such as a strong wind, lightning and gust caused a standstill of wind turbines.

• 문화기술의 융합
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• 제5권2호
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• pp.355-360
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• 2019

본 연구에서는 고속열차 주행 중 발생하는 풍하중 안정성 검토조건을 준용하여, 열차속도 300km/h와 360km/h에 대한 고속선로용 고무보판 패널 구조의 열차 풍하중에 대한 구조적 안정성을 검토하였다. 이를 위해 고무보판 패널 시스템이 가장 복잡한 구성으로 설치될 수 있는 현장조건을 적용하여 3차원 해석모델링을 이용한 정밀 수치해석을 수행하였으며, 이를 통해 고속열차 풍하중에 대한 고무보판 패널 시스템의 구조적 안정성을 해석적으로 입증하였다.

• Wind and Structures
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• 제15권2호
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• pp.131-145
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• 2012

Severe wind is one of the major natural hazards in Australia. The component contributors to economic loss in Australia with regards to severe wind are tropical cyclones, thunderstorms and subtropical (synoptic) storms. Geoscience Australia's Risk and Impact Analysis Group (RIAG) is developing mathematical models to study a number of natural hazards including wind hazard. This paper discusses wind hazard under current and future climate conditions using RIAG's synoptic wind hazard model. This model can be used in non-cyclonic regions of Australia (Region A in the Australian-New Zealand Wind Loading Standard; AS/NZS 1170.2:2011) where the wind hazard is dominated by synoptic and thunderstorm gust winds.