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金熙悳 慶一大學校 1996 論文集 Vol.13 No.2
In the aerodynamic studies for flexible structures, it has been desired to generate turbulent flows similar to natural wind in wind tunnel. In this study, an active gust generator is developed to simulate natural wind in a two-dimensional wind tunnel. The time varying wind velocity is produced by two active arrays which is controled by a personal computer. An active turbulence simulation method is also proposed which is based on power spectrum comparison. The proposed simulation method make it possible to control wind velocity fluctuations of horizontal and vertical components independently. As the experimental results, the turbulence characteristics of generated flows had a good agreement with target ones after a few modification of controlling signals. In particular, the power spectrum was coincided with target in the wide range of frequency. The range of obtained turbulence characteristics was sufficiently wide covering the properties of natural wind. The turbulence scales of generated flows are at least one order larger than those through passive methods.
차량 주행안정성확보를 위한 분출형 방풍시설물의 개발에 관한 실험적 연구
김희덕 한국풍공학회 2010 한국풍공학회지 Vol.14 No.3
In this study, the air-jet type windbreak is developed to improve traveling stability of vehicles on road. In wind tunnel tests, the wind pressure on simplified trailer model is measured for four kinds of air-jet type windbreaks and two traditional porosity windbreak walls, where the distance from windbreak and condition of banking are changed. As the results of study, the proposed windbreak has good performance equivalent to that of porosity wall with solidity ratio of 25% to 50%. The proposed air-jet type windbreak may be expected to improve the obstruction view of drivers traveling road. When it applied to bridges, the aerodynamic forces can be reduced comparing with traditional windbreak fences. 본 연구에서는 강풍시 차량의 주행안정성을 확보하기 위하여 분출형 방풍벽을 고안하였으며 풍동실험을 통하여 그 유효성을 검증하였다. 풍동실험에서는 4종류의 분출형 방풍벽과 기존의 다공형 수직방풍벽 2종류에 대해서 간이차량모형의 표면압을 측정하였으며 방풍벽으로부터 차량의 이격거리 및 성토부의 유무에 따라 방풍벽의 성능을 고찰하였다. 실험결과, 본 연구에서 고안된 분출형 방풍벽은 충실율 25%∼50%사이의 수직방풍벽과 동등한 방풍효과를 가지는 것을 확인하였으며 운전자의 시야확보에 유리하며 교량구조물에 적용시에는 기존의 방풍벽에 비하여 수풍면적이 감소하여 공기력을 저감시킬 수 있는 신개념의 방풍시설이 될 수 있을 것으로 기대된다.