흡수·차폐·방열 컴파운드 슬러리의 입도/공정조건/유변물성 상관관계

성민종(Min Jong Seong),안혜진(Hye Jin Ahn),박병진(Byeong Jin Park),이상복(Sang Bok Lee),황욱렬(Wook Ryol Hwang) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.7

WSN에서 노드의 잔여 에너지를 고려한 중앙집중식 클러스터링 방안

오종하(Oh Jong Ha),지소영(Ji So Young),변태영(Byun Tae Young),김덕춘(Kim Deok Chun),김선범(Kim Seon Beom),배한빈(Bae Han Bin),성민성(Sung Min Seong),장홍준(Jang Hong Jun) 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.2

TSP 문제 해결을 위한 유전 알고리즘 시뮬레이터

도성민(Seong-min Doe),박병준(Byung Joon Park) 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.2

홍수터여과에서 집수관의 최적설계 연구

피성민(Seong Min Pi),김승현(Seung Hyun Kim) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.6

홍수터여과에서 집수관의 설계에 대한 자료를 얻기 위해 실험실 규모의 모래통 실험을 수행하였으며, 집수관의 직경, 모래의 투수계수, 집수정의 수위 그리고 지표에서의 원수공급률 등의 변화에 따른 집수관에서의 수두분포와 지하수면 분포를 측정하였다. 측정결과를 수치해석코드에 적용하여 집수관 각 부위에서의 여과수 유입률도 파악하였다. 이들 자료로부터 홍수터여과에서 집수정의 운영수위를 낮춤으로 인한 부작용은 없을 것으로 예상되었으며, 적절한 회수능력에 비해 원수공급률이 큰 경우 대수층에서의 수평방향의 흐름이 발달하여 수평집수관의 통수능 부족을 보완함을 알 수 있었다. 이 경우 여과수의 토양중 이동거리가 늘어나므로 여과수의 수질개선에도 도움이 될 것으로 판단되었고, 따라서 홍수터여과에서는 강변/하상여과에서보다 더 작은 직경의 수평집수관을 사용할 수 있음을 알 수 있었다. 전체 수두손실중 수평집수관에서의 수두손실이 차지하는 비율이 수평집수관 출구유속과 비례함을 알 수 있었으며, 이를 이용하면 홍수터여과에서 수평집수관의 설계와 평가가 가능할 것으로 판단되었다. In order to obtain information on the design parameters of the horizontal laterals in floodplain filtration, laboratory-scale sand-box experiments were performed where the head distributions on the laterals and the groundwater profiles were measured according to the change in parameters including lateral diameter, hydraulic conductivity of the sand, water level at the well and raw-water supply rate. Measured data were analyzed using a numerical code in order to identify the discharge intensity distribution along the laterals. It was observed from the result that the lowering of the water level at the well had minimal adverse effect on the performance of the floodplain filtration. Results also elucidated that the low conveyance of the laterals to transmit the filtrate was compensated and supplemented by a natural augmentation in horizontal conveyance through the aquifer when the raw-water supply rate exceeded the adequate recovery rate. With this mechanism, the water quality is expected to improve further since the travel distance through the aquifer is amplified. Based on these findings it can be suggested that the diameter of the lateral used in the floodplain filtration may be smaller than those in riverbank/bed filtration. It was also found that the ratio between the head loss occurring in a lateral and the total head loss in the floodplain filtration was proportional to the exit velocities of the laterals, which may be used to design and/or evaluate the lateral in floodplain filtration.

충돌공기분류계에서 사각 ROD에 의한 전열증진 효과

금성민(Seong- Min Kum),오수철(Soo-Cheol Oh),서정윤(Jeong- Yoon Seo) 한국태양에너지학회 1995 한국태양에너지학회 논문집 Vol.15 No.1

본 연구는 2차원 충돌분류계의 포텐셜코어영역(H/B = 2)내에서 전열증진을 목적으로 전열면 앞에 폭 6mm인 정 4각 rod군을 설치하고 rod와 전열면간의 간극(C=1,2,4,6mm)과 rod와 rod 사이의 피치(P=30,40,50mm)를 변화시킬때의 유동특성과 전열특성을 실험적으로 규명하고 rod를 설치하지 않았을 경우와 비교·검토한 것으로 간극변화시에는 C=1mm인 경우가 전열성능이 가장 우수하였으며, rod의 피치(P)를 변화시킨 경우에는 rod가 없는 평판에 비해 각각 약 1.6배의 평균전열증진율이 나타났다. This research has been proceeded over the potential core region (H/B=2) of two -dimensional impinging air jet system, in which square rods( width of 6 mm) has been set up in front of heating surface in order to increase heat transfer. The objective of this research was to investigate the characteristics of heat transfer and air flow, in cases of the clearance from rods to heating surface ( C = 1, 2, 4, 6 mm) and the pitch between each rods(P=30, 40,50 mm) changed. And this research compared the above with the experimentation without rods. As result, heat transfer performance was best under the condition of C = 1 mm, in case clearance changed, and there was no serious difference in the effect of heat transfer augmentation in the case of pitch of rods changed.

충돌분류계에서 4각 난류촉진체에 의한 전열증진에 관한 실험적 연구

금성민(Seong-Min Kum),김종렬(Jong-Yul Kim),서정윤(Jeong-Yun Seo) 한국태양에너지학회 1994 한국태양에너지학회 논문집 Vol.14 No.1

본 연구는 2차원 충돌공기 분류계에서 공기의 흐름 방향과 수직이 되게 설치한 평판전열면 전방에 전열증진을 목적으로 난류촉진체인 정 4각 rod(폭 6㎜)의 pitch를 50㎜로 고정할 때 노즐출구속도(2, 8, 14, 18 ㎧), 노즐출구로 부터 전열면 사이의 거리 (H/B=2, 6, 10, 14) 및 rod 와 전열면 사이의 간극(C=1, 2, 4, 6㎜)을 변화시킬 때의 전열특성과 가시화 실험을 통해 유동특성을 규명한 결과 최대 열전달계수를 나타내는 조건은 H/B=10, C=1 ㎜이며 최대 전열증진율은 H/B=2, C=1 ㎜로서 rod를 설치하지 않은 평판보다 약 62% 증진된다. This research has been proceeded in the two-dimensional impinging air jet system, in which an impinging flat plate has been set up vertically to the way of air flow, and the pitch of square rod (width 6㎜), a turbulence promoter, has been fixed to be 50㎜ in front of impinging flat plate for the purpose of enhancement of heat transfer. With the experimental apparatus, we studied the characteristics of heat transfer in each case, changing nozzle exit velocity (2, 8, 14, 18 m/s), distance rate from nozzle exit to flat plate(H/B=2,6,10,14) and distance of rod and heating surface. Also we studied the characteristics of air flow through visualization.<br/> As a result, the condition that shows the maximum heat transfer coefficient was H/B=10, C=1㎜. And the maximum heat transfer growth rate was H/B=2, C=1㎜, which was improved about 62%, compared to the case to use a flat plate without a rod.

사각로드를 이용한 충돌분류계의 열저달증진에 관한 연구

금성민(Seong-Min Kum),이용화(Yong-Hwa Lee),서정윤(Jeong-Yun Seo) 한국태양에너지학회 1995 한국태양에너지학회 논문집 Vol.15 No.3

본 연구는 2차원 충돌공기분류계에서 공기의 흐름 방향과 수직이 되게 설치한 평판 전열면앞에 전열증진을 목적으로 난류촉진체인 정4각 로드군을 설치할때의 유동특성과 전열특성을 실험을 통해서 구명하고, 본 실험범위내에서 로드의 최적 설치조건을 제시하기 위한 실험적 연구이다. 실험은 먼저 로드를 설치하지 않은 평판에서의 전열특성을 밝힌후, 로드를 설치할 경우 로드의 피치가 40mm일때 로드와 전열면사이의 간극 및 로드폭 변화시의 유동특성과 전열 특성을 구명하여 로드를 설치하지 않은 평판과의 전열성능을 비교하였다. 본 실험범위내에서 전열면에 간극을 두고 로드를 설치하면 로드 바로 밑에서의 가속 및 로드에 의한 난류생성과 재부착에 의해 전열성능은 향상되며 로드폭을 변화시킨 경우에는 로드폭이 클수록 로드 바로 밑에서의 가속효과와 로드 직전에 와류의 영향 크게 작용하여 전열성능이 향상된다. This experimental study was carried out to examine the heat transfer characteristics of a 2 -dimensional impinging air jet on a flat plate with a set of square rods. The objectives of the study were to investigate the flow and heat transfer characteristics caused by the square rods. Experiment was carried out first without using the rods to establish the baseline heat transfer performance. Then, rods of different widths and clearances were installed to cause the turbulence on the fluid flow. When rods are installed in front of the plate, the acceleration of the flow and the turbulence generation due to the rods and reattachment of the flow seem to contribute to the observed heat transfer augmentation and the heat transfer augmentation increases as the clearance decreases. With wider individual rod the heat transfer coefficient is higher, which is due to the increased acceleration and development of the eddies just before the rods.

MESH에 의한 열전달증진에 관한 연구

금성민,정동수,김종보,Geum, Seong-Min,Jeong, Dong-Su,Kim, Jong-Bo 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.5

The objective of this research was to investigate the enhancement of heat transfer by mesh in impinging air jet system. The technique used in this research is to place mesh as a turbulence promoter in front of the impinging plate. The heat transfer characteristics with and without mesh, the effect of clearances between impinging plate and mesh, the effect of distance between nozzle exit and impinging plate, and the effect of nozzle exit velocity have been studied experimentally. When mesh was installed in front of the impinging plate, heat transer has been increased due to the acceleration between rectangular holes and divided small jets. When clearances are changed, heat transfer comes to a maximum under the condition of C = 1 mm, irrespective of nozzle exit velocity or H/B. Also the average heat transfer enhancement with mesh has been increased about 44% under the condition of U = 18 m/s, H/B = 2 and C = 1 mm, compared to the result of a flat plate without mesh. And the results of this research are compared with existing heat transfer augmentation method by rectangular or circular rod.

응축형 가스보일러 열교환기의 열전달특성에 관한 수치적 연구

김석철,금성민,이창언,Kim, Seok-Cheol,Geum, Seong-Min,Lee, Chang-Eon 대한기계학회 2001 大韓機械學會論文集B Vol.25 No.12

Characteristics of fluid flow and heat transfer in a tube with disk and annular baffle for heat exchanger of condensing boiler was numerically studied. The STAR-CD code was used to solve the governing equations and the temperature and flow fields were investigated. The interval between tube and annular baffle, height and diameter of baffle were selected as important design parameters, and the effects of these parameters on heat transfer and fluid flow were studied. As a result, in the case of with interval, the pressure was decreased, but heat transfer was increased. Heat transfer was slowly increased as the size of disk and annular baffle were increased and the distance between baffles were decreased. The pressure drop was rapidly changed fur diameter and size of disk and annular baffle. In addition, it was desirable that optimal conditions to design heat exchanger were about B$\_$a/R=0.5, L/R=1.

단일수분류 및 수분류군에 의한 열전달(2)-1열 수분류군-

엄기찬,이종수,금성민,Eom, Gi-Chan,Lee, Jong-Su,Geum, Seong-Min 대한기계학회 1997 大韓機械學會論文集B Vol.21 No.9

Experiments have been conducted to obtain local and average heat transfer coefficients associated with impingement of a row of circular, free surface-water jets on a constant heat flux surface. Nozzle arrays are a row of 3 jets (nozzle dia.=4.6 mm) and a row of 5 jets (nozzle dia.=3.6 mm), and the nozzle configuration is Reverse cone type revealed good performance in heat transfer. Nozzle-to-plate spacings ranging from 16 mm to 80 mm were investigated for two jet center to center spacings 25 mm and 37.5 mm in the jet velocity of 3 m/s (R $e_{D}$=27000) to 8 m/s (R $e_{D}$=70000). For a row of 3 jets and a row of 5 jets, the stagnation heat transfer of the central jet is lower than that of adjacent jets. In the wall jet region between jets, for small nozzle-to-plate spacing and large jet velocity, the local maximum in the Nusselt number was observed, however, for small jet velocity or large nozzle-to-plate spacing, the local maximum was not observed. Except for the condition of $V_{O}$=8 m/s and H/D=10, the average Nusselt number reveals the following ranking: a row of 5 jets, a row of 3 jets, single jet. For a row of 3 jet, the maximum average Nusselt number occurs at H/D=8 ~ 10, and for a row of 5 jets, it occurs at H/D=2 ~ 4. Compared with the single jet, enhancement of average heat transfer for a row of 3 jets is approximately 1.52 ~ 2.28 times, and 1.69 ~ 3.75 times for a row of 5 jets.ets.s.