집적형 하이브리드 구동장치의 내부 유동 분석을 위한 리드밸브 특성 연구

이수홍(Soo-Hong Lee),현철봉(Cheol-Bong Hyun),구남서(Nam Seo Goo),조진호(Jin Ho Cho),고한서(Han Seo Ko) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

A self-contained hybrid actuator is a kind of a piston-cylinder device which is operated by a micro pump. The actuator is used for an air plane, a guided weapon, a vehicle, etc. since it has high actuating power and velocity although its size is small. The actuating velocity of the self-contained hybrid actuator is influenced by the actuating frequency of the pump. reed valve, and applied voltage. in this study, the influence of the actuating frequency and the reed valve on the actuating velocity was investigated by analyzing internal flow distribution. the FSI (Fluid Structure Interacting) of the ANSYS with the turbulent model of SST was used for the numerical analysis to calculate the internal flow by the pump frequency. Also, the effect of the shape and the thickness of the reed valve was studied. The output velocity form the numerical analysis increased with the actuating frequency initially, and the velocity decreased after 250Hz by the flow loss because the working fluid velocity could not follow the accelerating of the piezo pump. Also, the U-type reed valve showed higher output velocity than the original shape did because of creation of relatively small vortex.

OLED 디스플레이용 유기용매를 이용한 전기수력학적 잉크젯 패터닝에 관한 연구

이수홍(Soo-Hong Lee),신동호(Dong-Ho Shin),Xuan Hung Nguyen,고한서(Han Seo Ko) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

An electrohydrodynamic (EHD) jet which is a revolutionary inkjet technology can produce much smaller droplets than nozzle sizes even for highly viscous liquid. Although there are many modes of the ejection mechanism from the EHD nozzle, a cone-jet mode, a pulse-jet mode and a micro-dripping mode have been analyzed by capturing the jetting phenomena using organic solvents as working fluids in this study to find out the optimum liquid for each mode at the required condition. Droplet ejection from the EHD inkjet nozzle depends on many factors such as an onset voltage, liquid conductivity, surface tension, viscosity, etc. Among the factors, the dielectric constant and the viscosity have been selected especially to investigate the effect on the stable jetting because they are dominant factors for the EHD jetting system. Also, the line patterning has been performed to analyze the effect of the factors for OLED.

전기수력학 잉크젯의 토출 유량 분석

이수홍(Soo-Hong Lee),이필호(Pil-Ho Lee),김대훈(Dae-Hoon Kim),우장미(Chiang Wei Yu),김영현(Young Hyun Kim),이상원(Sang Won Lee),고한서(Han Seo Ko) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

가시화 기법을 이용한 룸에어컨 유동 분포 분석

이수홍(Soo-Hong Lee),라선욱(Seon-Uk Na),강근(Geun Kang),고한서(Han Seo Ko) 한국가시화정보학회 2009 한국가시화정보학회 학술발표대회 논문집 Vol.2009 No.11

Flow distributions of a room air conditioner (RAC) have been investigated using a visualization technique such as a Particle Image Velocimetry (PIV) to analyze an efficiency and noise of the RAC. Pitot tubes have also been used to measure the flow velocity inside the RAC with various positions to confirm the measurement accuracy of the PIV technique. Then, numerical analyses have been carried out by developing Computational Fluid Dynamics (CFD) programs to calculate the flow velocity inside the RAC. From the results of the experimental and numerical studies, new designs of the RAC have been proposed to improve the efficiency of the RAC. Various flow distributions by controlling the outlet flow velocity have been observed experimentally and numerically to compare the efficiencies between different RAC models in this study.

EHD Ink-Jet을 이용한 3차원 Scaffold 구조물 제작에 관한 연구

이수홍(Soo-Hong Lee),이필호(Pil-Ho Lee),김대훈(Dae-Hoon Kim),우장미(Chiang Wei Yu),이상원(Sang Won Lee),고한서(Han Seo Ko) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.5

Study on Variation of Onset Voltage by Electric Conductivity for Electrostatic Droplet Ejection

이수홍(Soo-Hong Lee),Nguyen Xuan Hung,김승배(Seung-Bae Kim),고한서(Han Seo Ko) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

An effect of applied electric potential and physico-chemical parameters on a droplet diameter has been analyzed numerically. Smaller droplets can be ejected from a nozzle by applying electrostatic potential between the nozzle and liquids. Although the droplets have been formed until the critical value of the electric potential, unstable liquid jets with multiple satellite droplets have been observed at higher electric potentials. The critical value of the electric potential is called as an onset voltage in this study. Equations for the onset voltage have been developed by many researchers. Since the developed equations are appropriate for only their cases, a numerical analysis has been performed in this study to calculate the droplet diameters and the onset voltages accurately by various functions such as a surface tension of liquid, a distance between a nozzle and electrode, an inside diameter of the nozzle, etc.

Study on Flow Structure inside Room Air Conditioner Using Visualization Technique

이수홍(Soo-Hong Lee),라선욱(Seon-Uk Na),강근(Geun Kang),고한서(Han Seo Ko) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

Whole flow fields of a room air conditioner (RAC) have been visualized by a Particle Image Velocimetry (PIV) technique to analyze the flow structure with various inlet and outlet angles, and to control an eccentric vortex which affects an efficiency and noise of the RAC. A test model with 5 stages of a cross flow fan has been manufactured and a transparent acryl has been installed at the side of the test model for the PIV experiment. The inlet and outlet flows and the flow inside the cross flow fan have been analyzed by varying the inlet grill angles and outlet blade angles. The movement of the eccentric vortex has been investigated experimentally by developing the measurement technique for the inner flow field of the cross flow fan. From the visualization of the inner flows, the origins of the noise inside the RAC and the condensation points around the outlet parts of the cold air have been observed and the solution of the problems can be proposed in this study.

토기를 통해 본 청동기시대 사회상

이수홍(Lee, Soo Hong) 부산고고학회 2020 고고광장 Vol.- No.27

가장 많이 잔존하는 고고자료인 토기를 활용해 청동기시대 사회상에 접근하고자 하였다. 기존의 토기 연구가편년에 집중되어 있었는데, 편년 이외 토기를 통해 무엇이 밝힐 수 있는지에 대한 검토이다. 토기의 표면에 잔존하는 흑반의 관찰을 통해 어떻게 소성되었는지, 그을음과 탄착흔의 관찰을 통해 어떻게취사하였고, 어떤 음식을 조리하였는지에 대해서 접근할 수 있다. 토기의 기종 차이는 지역성을 나타내기도 하는데, 생업의 차이를 반영하는 것이다. 동일한 기종이라도 기형이나 문양에서 지역성을 보인다. 동남해안지역의 검단리식토기, 부산지역의 연지동식토기, 호서지역의 플라스크형 적색마연토기, 경남지역의 함안식적색마연토기, 서부경남과 동부전남지역의 채문토기는 특정지역에서만출토되어 지역상을 보인다. 돌대문토기, 횡대구획문토기, 타날문토기, 점토대토기는 이주의 결과 한반도 남부지역에 출현하였으며, 파수부 심발형토기, 파수부 적색마연토기, 플라스크형 적색마연토기는 주민의 왕래에 의해 인접한 곳으로 전파되었다. 토기의 분포권을 집단과 연결시킨 최초의 사례는 고조선의 표지적인 유물로 인식되어 온 미송리형토기이다. 최근에는 점토대토기를 고조선과 연결시키기도 한다. 집단의 정체성에 대한 연구는 고고학에서 끊임없이 추구해야 할 연구 분야지만 신중을 기할 필요가 있다. This study set out to approach the social aspects of Bronze Age with pottery, which offers the most affluent archeological materials remaining today. As the previous pottery studies has been focused on dating, they were the studies of what can be revealed through the features of pottery itself without the dating. The investigator examined the methods of making pottery by observing carbon traces by firing on the surfaces and the cooking methods and types of food they cooked by observing soot and scorching. Differences among the types of pottery reflected local colors or different occupations among different areas. Even under the same type of pottery, the local colors were reflected through forms and patterns. The Geomdanri-type pottery of the southeastern coastal area, Yeonjidong-type pottery of Busan, flask-type red burnished jars of Hoseo region, Haman-type red burnished jars of Gyeongnam region, and pottery with an eggplant design of western Gyeongnam and eastern Jeonnam were excavated only in certain respective areas and reflected their local aspects. The Doldaemun pottery, pottery with a line section, pottery with a stamp design, and clay-stripe pottery were excavated in the southern regions of the Korean Peninsula as a result of migration. The deep bowl pottery with handles, red burnished pottery with handles and holes, and flask-type red burnished pottery were spread to adjacent places through the travel of residents. The first case of connecting the distribution areas of pottery to a group was the Misongri-type pottery regarded as a marker artifact of Gojoseon. In recent years, the clay-stripe pottery has been connected to Gojoseon. The field of archeology needs to pursue research on the identity of a group constantly with caution.

영남지역 묘역식지석묘의 특징과 구산동지석묘의 성격

이수홍(Soo Hong Lee) 부산고고학회 2023 고고광장 Vol.- No.32

영남지역의 묘역식지석묘를 검토하고, 구산동지석묘의 특징과 성격에 대해 살펴보았다. 영남지역에는 현재까지 56곳의 유적에서 340여기의 묘역식지석묘가 조사되었다. 묘역식지석묘는 영남 각지에 분포한다. 청동기시대 전기의 늦은 시기에 출현하여 초기철기시대까지 지속적으로 축조되었다. 청동기시대 후기에는 거대한 묘역식지석묘가 군집을 이루어 축조된다. 이 시기는 거대한 묘역식지석묘가 계층화의 과정을 보여주지만, 아직 완전한 불평등사회로 진입한 것은 아니다. 초기철기시대가 되면 불평등사회로 진입하면서, 공동체를 위한 것이 아닌 1인을 위한 무덤이 축조되는데 무덤군에서 거대한 묘역식지석묘는 단 1기만 축조된다. 구산동지석묘는 그 규모에서 압도적인 거대함, 무덤군에서 1기만 촌재하는 묘역식 무덤, 상석이 묘역에 직교하고, 매장주체부가 목관(木棺)이며, 출토유물이 기존의 지석묘 출토유물과는 이질적인 옹(甕)과 두형토기(豆形土器)라는 특징이 있다. 초기철기시대에 축조된 것이 확실하며 무덤으로 축조되었다. 김해지역에 새로운 이주민의 정착이 늦어진 것은 구산동지석묘를 축조할 만큼 강력한 세력이 있었기 때문이다. 구산동지석묘는 초기철기시대 재지민이 축조한 최후의 군장묘이다. 청동기시대가 끝나는 전환기에 변화를 받아들이는 모습을 상징적으로 보여준다. 이후 청동기시대는 종언하고 새로운 시대가 개막한다. This study set out to review dolmens with a boundary in the Yeongnam region and examine the characteristics and nature of the Gusan-dong Dolmen. In the Yeongnam region, approximately 340 dolmens with a boundary were investigated at 56 relics. The distribution of dolmens with a boundary covers the entire Yeongnam region. They appeared in a relatively late period of the former part in the Bronze Age and continued to be constructed until the early Iron Age. Entering the latter part of the Bronze Age, large-scale dolmens with a boundary were built in clusters. This period witnessed the stratification process of such large-scale dolmens with a boundary, but they had not entered a completely unequal society yet. Entering the early Iron Age, they entered an unequal society and built graves for individuals rather than the community. Only a large-scale dolmen with a boundary was built for a grave group. The Gusan-dong Dolmen is characterized by its overwhelmingly vast size, its uniqueness as the only dolmen with a boundary in the grave group, its stone stable orthogonal to the grave boundary, its wooden coffin for the subject of burial, and its artifacts heterogeneous from the ones of the old dolmens including jars and pedestal vessel pottery. There is no doubt that the dolmen was built as a tomb in the early Iron Age. The settlement of new migrants in the Gimhae area was late because there was a force that was powerful enough to build the Gusan-dong Dolmen in the area. The Gusan-dong Dolmen was the last chief tomb built by local people in the early Iron Age, displaying their acceptance of changes during a transitional period at the end of the Bronze Age in a symbolic way. It marked the end of the Bronze Age and opened a new age.

표면장력에 따른 정전기적 노즐의 액적 토출 특성 분석

이수홍(Soo-Hong Lee),신동호(Dong-Ho Shin),Xuan Hung Nguyen,고한서(Han Seo Ko) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.4