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 : 安壽煥 (검색결과 317 건)
- 무료
- 기관 내 무료
- 유료
-
안수환,손강필 경상대학교 농업생명과학연구원 2001 농업생명과학연구 Vol.35 No.-
원통다관형 열환기 내 고체입자들을 자연 순환시켜 오염물질을 세정함으로서 항상 오염이 되지 않는 순환유동층 열교환기를 개발하는데 필요한 기초자료를 제공하고자, 다양한 고체입자들에 따른 열전달과 유동특성의 변화를 조사하고, 또한 장시간에 걸친 오염 실험을 행하여 아래와 같은 결론을 얻었다. 유체 속도가 증가할수록 충돌횟수가 감소하였고 구리의 경우 1.3 m/s이상의 유속에서는 충돌이 이루어지지 않고 상승하였다. 비중이 클수록 대체로 항력계수가 증가하였고 내부 유동일 경우가 외부유동일 경우보다 항력계수가 컸다. Al 입자의 경우 순환 유동층 열교환기의 튜브내 유속을 0.4m/s~0.7m/s 범위로 하면 오염을 제거할 수 있을 뿐만 아니라 열전달계수도 고체입자를 순환하지 않는 열교환기보다 2배 이상의 열전달계수 상승효과를 얻었다. The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the drag coefficients of particles in the internal flow were higher than in the external flow, in addition, the solid particle periodically hitting the tube wall broke the thermal boundary layer, and increased the rate of heat transfer. Particularly when the flow velocity was low, the effect was more pronounced.
-
Characteristics of Heat Transfer in the Channel with Twisted Tape
안수환,Ho Keun Kang 대한설비공학회 2007 International Journal Of Air-Conditioning and Refr Vol.15 No.3
Heat transfer distributions and friction factors in square channels (3.0×3.0cm) with twisted tape inserts and with twisted tape inserts plus interrupted ribs are respectively investigated. The rib height-to-channel hydraulic diameter ratio, e/Dh, is kept at 0.067 and test section length-to-hydraulic diameter ratio, L/Dh is 30. The square ribs are arranged to follow the trace of the twisted tape and along the flow direction defined as axial interrupted ribs. The twisted tape is 0.1mm thick carbon steel sheet with diameter of 2.8cm, length of 90cm, and 2.5 turns. Two heating conditions are investigated for test channels with twisted tape inserts and rib turbulators:(1) electric heat uniformly applied to four side walls of the square duct, and (2) electric heat uniformly applied to two opposite ribbed walls of the square channel. Results show that the twisted tape with interrupted ribs provides a higher overall heat transfer performance over the twisted tape with no ribs.Nomenclature†Corresponding authorTel.: +82-55-640-3125; fax: +82-55-640-3128E-mail address: swahn@gaechuk.gsnu.ac.kr: heat transfer area [2]: hydraulic diameter []: rib []: friction factor: Mass flux []: heat transfer coefficient []: thermal conductivity []: mass flow rate []: Nusselt number, : rib pitch []: heat transfer rate []: Reynolds number, x: distance from entrance []
-
-
사각채널에 설치된 배플이 열전달과 마찰계수에 미치는 효과
안수환,강호근,배성택,송민호,Ahn, Soo-Whan,Kang, Ho-Keun,Bae, Sung-Taek,Song, Min-Ho 한국마린엔지니어링학회 2006 한국마린엔지니어링학회지 Vol.30 No.6
The present work investigates the local heat transfer characteristics and the associated frictional loss in a rectangular channel with inclined solid and perforated baffles to obtain the basic design data for gas turbine. Five different geometries of baffles such as 1) solid (without hole), 2) three holes, 3) six holes, 4) nine holes, 5) twelve holes were covered. A combination of two baffles of same overall size is used. The flow Reynolds number is ranged from 28,900 to 70,100. The placement of baffles augments the overall heat transfer greatly by combining both jet impingement and the boundary layer separation. The present results show that the average Nusselt number distribution is strongly dependent on number of holes in the baffle plates, i.e., the average Nusselt number increases with increasing number of holes. The friction factor decreases also with increasing the number of holes. however. its value increases with increasing the Reynolds number.
-
Heat Transfer Augmentation in a Divergent Duct with Angled Ribs
안수환,이명성 대한설비공학회 2017 International Journal Of Air-Conditioning and Refr Vol.25 No.1
Heat transfer characteristics in the rectangular divergent duct with parallel angled ribs are experimentally compared with the straight smooth circular duct. The ribs with four different parallel angles ( ¼ 30, 45, 60, and 90) are glued on the duct's two opposite walls as well as on the duct's one sided wall only, respectively. The 0.72-inclined walls are installed at the two opposite walls of the rectangular divergent duct. The test section of 1000mm long has the cross section of 100 『 75mm2 at inlet and 100 『 100mm2 at exit. The ribbed walls are manufactured with a rib height ðeÞ ¼ 10mm and the ratio of rib spacing (p) to height(e) ¼ 10. The main ¯ndings are summarized that the increase in the dimensionless Nusselt number for the flow attack angles can be seen in the order of 90, 30, 60, and 45 at the two opposite ribbed divergent wall ducts, in addition, the average Nusselt number in the divergent rectangular duct with two opposite ribbed walls is somewhat greater than in the ribbed straight cross-sectional rectangular duct.
-
왕복운동을 하는 사각채널에서 파형테이퍼가 열전달에 미치는 효과
안수환,배성택 한국마린엔지니어링학회 2003 한국마린엔지니어링학회지 Vol.27 No.5
This Paper describes a detailed experimental investigation of heat transfer in a reciprocating smooth rectangular duct having only the bottom wall heated with reference to the design of a piston for a marine propulsive diesel engine The Parametric test matrix involves Reynolds number and reciprocating radius, respectively, in the range of 1.280∼4.100, and 7∼15 cm with five different reciprocating frequency tested. namely. 1.7, 2.2, and 2.6 Hz. The effects of three different hemi-triangular wavy type tapers on the heat transfer in the reciprocating rectangular channel using the air as a working fluid were check out. The present work confirms that the Nusselt number in the channel with the triangular wavy type taper is lower than without the triangular wavy type taper.
-
-
-
안수환,손강필 한국마린엔지니어링학회 2002 한국마린엔지니어링학회지 Vol.26 No.6
The influence of reciprocating frequency and radius on heat transfer in the roughened rectangular channel is experimentally investigated. The aspect ratio (width/height) of the duct is 2.33 and the rib height is one fifteenth of the duct height. And the ratio of rib-to-rib distance to rib height is 10. The discrete ribs were periodically attached to the button wall of the duct with a parallel orientation. The parametric test matrix involves Reynolds number, reciprocating, and reciprocating radius, in the ranges, 1,000∼6,000, 1.7∼2.5 HB and 7∼15cm, respectively. The combined effects of reciprocating frequency and reciprocating radius have considerable influence on the heat transfer due to the modified vortex flow structure.
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
