무주사 약물 전달 장치의 분말 속도 측정

김규완(Gyu Wan Kim),김윤상(Yun Sang Kim),Zhang Guang,Tokitada Hashimoto,Toshiaki Setoguchi,김희동(Heuy Dong Kim) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

In this study basic research was carried out to obtain the fundamental data of the needle-free injection system with powder injection. Improved needle-free injector was designed and manufactured. In addition, we measured the velocity of the powder particles, this was performed by simply visualizing the macro mode traveling at supersonic velocity to measure the number of milliliters of the square particles with high spatial and temporal resolution using high-speed video camera. The velocity data were acquired by the particle tracking velocimetry method after image processing.

CDA 인입공기 증발냉각을 통한 압축기 성능 개선장치 개발 연구

김규완(Heuy Dong Kim),박진욱(Jin Ouk Park),김희동(Heuy Dong Kim) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.11

CDA(Clean Dry Air) System 에서 공기 압축기는 핵심 설비이자 소비되는 전력의 대부분을 차지한다. 그리하여 압축기 성능(ECI)을 개선함으로써 CDA System 전체성능을 크게 향상 시킬 수 있다. 종래의 많은 연구를 통해 인입공기의 온/습도 조건이 압축기에 미치는 영향에 대해 잘 알려져 있으나, 본 연구에서는 인입공기의 조건에 따라 소비되는 실제 전력 및 토출유량의 상관관계를 조사하였다. 또한 증발 냉각장치를 설치하여 인입공기 조건의 다양한 변화를 통하여 압축기성능에 미치는 영향을 연구하였다. 얻어진 결과로부터 인입공기의 온/습도가 낮을수록 압축기성능이 개선되었고, 증발냉각장치를 설치하였을 때 압축기성능이 개선됨을 알았다. In the present study, water vapor is injected at various positions in a Clean Dry Air (CDA) system such as a system inlet duct, compressor inlet, and compressor outlet by humidified air turbines. The application of evaporative cooling reduces the compression work and enhances the Energy Consumption Index (ECI) per unit volume. The main purpose of this study is to investigate the compressor power performance with different inlet air temperatures and humidity conditions. It is found that the actual power consumption and discharge flow are significantly influenced by the inlet air temperature as well as relative humidity. The results obtained during this study are compared both numerically and experimentally and are found to be in very good agreement.

베르누이 부상유동의 이론해석 및 수치 해석적 연구

김규완(Gyu Wan Kim),김진현(Jin Hyeon Kim),남종순(Jong Soon Nam),김희동(Heuy Dong Kim) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

More attentions have been paid on non-contact handling approaches in the field of semiconductor production process, especially the application in wafer. Since the contact handling always leads to damaging and contaminating of the products, it is highly desirable to get effective non-contact handling for improvement of the product quality. The pneumatic levitation is based upon Bernoulli principle. However, this method is known to consume large gas flow rate which can rise the cost of products. Moreover, the recent trend of wafer is increasing its size so that more power is required to lift up and transport the wafer. In this case, the gas flow rate should be increased and the compressible effects of gas may be of practical importance. In the present paper, a computational fluid dynamics method has been used to get insight into the Bernoulli levitation. A circular plate of work piece was employed as a model of wafer. The 3-dimensional compressible Navier-Stokes equations furnished with the SST k-ω turbulence model were solved using a fully implicit finite volume scheme. Gas flow rate, diameter of work piece and the clearance gap between work piece and circular cylinder were varied to investigate the flow characteristics inside. The levitation force was analyzed in terms of gas flow rate and clearance gap. It is known that there is an optimal clearance gap for the lifting force and increasing the supply gas flow rate results in a larger lifting force.

CDA인입공기 증발냉각을 통한 압축기 성능 개선장치 개발 연구

김규완(Gyu-Wan Kim),박진욱(Jin-Ouk Park),박태언(Tae-Eon Park),김희동(Heuy-Dong Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

The compressor power performance namely the Energy Consumed Index (ECI) is very important to the Clean Dry Air (CDA) System semiconductor industries as well as many engineering applications. In humidified air turbines water can be injected at various positions such as system inlet duct, compressor inlet or outlet. These techniques may be stated as inlet fogging, wet compression and after fogging, respectively. The application of evaporative cooling reduces compression work and enhances the ECI per unit volume. The main purpose of this study is to investigate the compressor power performances with different inlet air temperature and humidity conditions. It is found that the actual power consumption and discharge flow are significantly influenced by the inlet air temperature as well as relative humidity. Moreover, it is observed that for lower values of ECI, the total performances of compressor in CDA Systems have shown better approximation. Finally, the results obtained by this study are compared both in numerically and experimentally and it is found to be in very good agreement.

베르누이 부상유동의 이론해석 및 수치해석 연구

남종순(Jong Soon Nam),김규완(Gyu Wan Kim),김진현(Jin Hyeon Kim),김희동(Heuy Dong Kim) 대한기계학회 2013 大韓機械學會論文集B Vol.37 No.7

공압 부상은 베르누이 원리에 기초한다. 그러나 공압 부상 방법은 제품의 원가 상승의 요인이 되는 대량의 유량을 소모하는 것으로 알려져 있다. 이 논문에서는 베르누이 부상 유동의 통찰력을 얻기위해 수치 해석 연구를 수행하였다. 3차원 압축성 Navier-Stokes 방정식과 SST k-ω 난류모델에 유한 체적법을 적용하여 계산하였다. 기체 유량, 공정 제품의 직경 그리고 원형실린더와 공정 제품사이의 간극을 다양하게 변화하여 공정 제품 주위의 유동 특성을 조사하였다. 그 결과 부상력을 위한 최적의 간극과 공급 기체 유량이 증가하면 큰 부상력이 발생한다는 것을 알았다. Pneumatic levitation is based upon Bernoulli’s principle. However, this method is known to require a large gas flow rate that can lead to an increase in the cost of products. In this case, the gas flow rate should be increased, and the compressible effects of the gas may be of practical importance. In the present study, a computational fluid dynamics method has been used to obtain insights into Bernoulli levitation flows. Three-dimensional compressible Navier-Stokes equations in combination with the SST k-ω turbulence model were solved using a fully implicit finite volume scheme. The gas flow rate, workpiece diameter,and clearance gap between the workpiece and the circular cylinder were varied to investigate the flow characteristics inside. It is known that there is an optimal clearance gap for the lifting force and that increasing the supply gas flow rate results in a larger lifting force.

Micro-Shock Tube 유동에 대한 실험적 연구

박진욱(Jin-Ouk Park),김규완(Gyu-Wan Kim),Md.Alim Iftakhar Rasel,김희동(Heuy-Dong Kim) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.5

Micro shock tube에서 발생하는 비정상파 거동을 실험적으로 조사 하기위해 파막 실험을 수행하였다. 실험은 스테인리스 재질의 micro shock tube를 사용하였으며, 총 8개의 압력센서를 설치하여, 충격파관에서 발생하는 충격파 및 팽창파를 측정하였다. 초기 압력비는 6.3에서 30.5까지 변화시켰으며, 관의 직경은 3mm와 6mm로 하였다. 그리고 두 가지 재질의 격막을 사용하여 격막 조건을 다양하게 실험을 수행하였다. 그 결과로부터 초기 압력비 및 관 직경의 증가에 따라 관내에서 발생되는 충격파 강도는 커지며, 가장 얇은 재질의 격막 조건에서 가장 큰 충격파 강도가 발생했다. 그리고 충격파 감쇠는 관의 직경에 가장 큰 영향을 받았다. The flow characteristics in micro shock tube are investigated experimentally. Studies were carried out using a stainless steel micro shock tube. Shock and expansion wave was measured using 8 pressure sensors. The initial pressure ratio was varied from 4.3 to 30.5, and the diameter of tube was also changed from 3mm to 6mm. Diaphragm conditions were varied using two types of diaphragms. The results obtained show that the shock strength in the tube becomes stronger for an increase in the initial pressure ratio and diameter of tube. For the thinner diaphragm, the highest shock strength was found among varied diaphragm condition. Shock attenuation was highly influenced by the diameter of tube.

Micro Shock Tube 유동에 대한 실험적 연구

박진욱(Jin-Ouk Park),김규완(Gyu-Wan Kim),Md.Alim Iftakhar Rasel,김희동(Heuy-Dong Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

Micro shock tubes are miniature devices used for various applications in micro scale technology. Flow characteristics in micro shock tubes are different compared with conventional macro shock tube owing to influence of the smaller diameter. Hence, it generates flow with higher Knudsen number and boundary layer effect. In this paper, the flow characteristics and unsteady wave motions in micro shock tube of different tube diameters, 3mm and 6mm, are investigated by experimental studies. Each shock and expansion propagation at different pressure ratios and diaphragm conditions are also investigated. Driver section pressure was adjusted using compressor and the driven section pressure was maintained at atmospheric condition. The diaphragm was ruptured using a hand operated needle system and was used on two different materials. Time dependent static pressures at 8 different locations were measured using pressure transducers. The results obtained show that as the diameter and initial pressure ratio decrease the shock wave velocity and expansion wave velocity also decrease. The changed diaphragm material also influence to unsteady wave motion.