http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 임희창(Lim, Heechang) (검색결과 116 건)
- 무료
- 기관 내 무료
- 유료
-
O-ring을 이용한 원주의 항력감소에 관한 실험적 연구
임희창,이상준,Lim, Hee-Chang,Lee, Sang-Joon 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.8
The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167 D, 0.05D and 0.067 D with pitches of PPD=2D, 1D, 0.5D and 0.25D. The drag force, mean velocity and turbulence Intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of Re$_{D}$=7.8$\times$10$^3$~1.2$\times$10$^{5}$ . At Re$_{D}$=1.2$\times$10$^{5}$ , the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared that with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.der.
-
Orifice shape effect of the TLCD system under a low frequency
임희창,Lim, HeeChang The Korean Society of Visualization 2014 한국가시화정보학회지 Vol.12 No.1
Bluff bodies under the external periodic force vibrate at their own natural or forced frequency. Rectangular bodies or similar structures such as high-rise towers and apartments, and recently a well-cited application - offshore floating bodies, usually needs to reduce these vibrations for stability and the mode control. Therefore, this study is aiming to reduce or control the vibration of a structure by a passive control method, i.e., TLCD (Tuned Liquid Column Damper). Controlling a moving body with a TLCD based on a variety of the orifice shape has been preliminary studied. In order to get a proper control, an optimized study is made on the design of the orifice shape, which has internal plates with the holes. The results show the force acting on the body due to the periodic movement highly depends on the number of holes on the plate and the height of the water level. Therefore, the optimum shape of the orifice and the height of the water level should be confirmed by a series of experiments.
-
미래 풍력발전산업의 집적지육성을 위한 녹산클러스터 발전방향
임희창,한규택,장광호,진성호,김용환,Lim, Hee-Chang,Han, Gyu-Taek,Jang, Gwang-Ho,Jin, Seong-Ho,Kim, Yong-Hwan 산업클러스터학회 2009 산업클러스터 Vol.3 No.1
Wind power is the most rapidly growing energy source in the world. Increased focus on climate changes and renewable energy is supporting the wind power industry in gaining momentum. Noksan wind cluster in Busan has been a major area in manufacturing the elementary parts of wind turbine. Despite growing recognition of the significance of Noksan, there has been only limited attention paid and in recent years. This paper reviews the literature of the current burning issues in wind turbine industries in the western countries. In addition, it describes the present state of Noksan wind power generation cluster and suggests the future plans to make it more effective complex.
-
O-ring 을 이용한 원주의 저항감소에 관한 실험적 연구
임희창(Hee Chang Lim),이상준(Sang Joon Lee) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4
The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force<br/> acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of<br/> diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167D, 0.05D and<br/> 0.067D with pitches of PPD=1D, 0.5D and 0.25D. The drag force, mean velocity and turbulent<br/> intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based<br/> on the cylinder diameter in the range of ReD=7.8×103~1.2×105. At ReD=1.2×105, the cylinder fitted<br/> with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about<br/> 5.4%, compared with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not<br/> so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence<br/> intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders<br/> was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of<br/> vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with<br/> the smooth cylinder.
-
-
-
유동방향 홈을 가지는 그루브 원주 주위 유동에 관한 Cinematic PIV 측정 연구
임희창(Hee Chang Lim),이상준(Sang Joon Lee) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5
Flow structures around a circular cylinder with different grooved surfaces (U- and V-shaped)<br/> have been investigated experimentally. The results were compared with those for a smooth cylinder<br/> of the same diameter D. The drag force acting the cylinders were measured for Reynolds numbers<br/> based on the cylinder diameter (D=60mm) in the range ReD=8×103~1.4×105. At ReD=1.4×105, the<br/> U-type grooved surface reduced the drag coefficient by 18.6%, compared with the smooth cylinder.<br/> However, the drag reduction of V-type grooves was only 2.5% at the same Reynolds number. In<br/> order to see the time-evolution of velocity field behind the grooved cylinders, the cinematic PIV<br/> technique was employed. Particle images were acquired at the time interval of 5ms(=200fps),<br/> corresponding to about 1% of the formation period of large-scale vortices. The sequential velocity<br/> fields show three-dimensional space-time relationship between the instantaneous streamwise<br/> vorticity and the phase of the large-scale vortex formation. Unlike the periodic vortex structure in<br/> the near-wake region at low Reynolds number of 100s, the vortex structure at Re = 12,000 is not so<br/> clearly periodic in the vortex formation region.
-
-
-
임희창 ( Hee Chang Lim ),최석근 ( Seok Keun Choi ) 충북대학교 건설기술연구소 2013 건설기술논문집 Vol.32 No.1
Natural disaster has highly been increasing to climate change, it also birings huge damage. This study aims to predict natural disaster damage and enhance quality of flood disaster map using spatial information. The developed flood disaster map was used GRM method with various scale of topography and river basin characteristic data in Mushimuchun, Chengju, KOREA. The optimized grid size was calculated by comparing disaster map obtained by field survey, adopted diffuse model in target basin. The precise flood disaster map was made through performed flood modeling with input data and that was able to develop prediction map of target area.
KISS연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
