http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
방전 및 산화촉매 필터로 구성된 디젤 배기계의 성능평가
김영권(Youngkwon Kim),김태화(Taehwa Kim),김민우(Minwoo Kim),신귀수(Gwisu Shin),김근주(Keunjoo Kim),오영택(Young Taig Oh) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.5_1
The high-voltage discharge/oxidation catalyst filter was designed to reduce the particulate emission in automobile. The filter was located on the exhaust pipe of engine. The electrical power of low current which have the high voltage was applied. The experimental measurement on smoke density was performed by the implementation of the automobile named, "Carnival", a product of KIA Motor ㏇ at the uniform engine speed and brake on. The smoke opacity in optical absorption measurement showed that the high voltage discharge/oxidation catalyst filter leads to reduce the amount of emission. To characterize the performance of the filter, we used various experimental equipment. The results showed that the adoption of filter reduced the amount of the particulate matters.
초고속 원심방사에 의한 아세트산프로피온산 셀룰로오스/폴리부틸렌 숙시네이트 다공성 마이크론 섬유 제조
김태영(Tae Young Kim),김미경(Mi Kyung Kim),김진수(Jinsoo Kim),이정언(Jungeon Lee),정재훈(Jae Hoon Jung),김영권(Youngkwon Kim),김태현(Tae Hyeon Kim),김기영(Ki Young Kim),염정현(Jeong Hyun Yeum) 한국염색가공학회 2023 韓國染色加工學會誌 Vol.35 No.4
Cellulose is an abundant biodegradable material in nature with excellent properties, but due to its poor processability, it has been widely studied for processing through modification. Cellulose acetate propionate (CAP) is a cellulose derivative in which the hydroxyl group of cellulose is replaced by acetyl and propionyl groups. CAP has several advantages, such as excellent solubility, structural stability, light and weather resistance, and good transparency. Porous nanofibers with excellent specific surface area, which can be applied in various fields, can be easily formed by the phase separation method using highly volatile solvents. High speed centrifugal spinning is a nano/micro fiber preparation method with advantages such as fast spinning and easy alignment control. In this study, a CAP/polybutylene succinate (PBS) spinning solution with chloroform as solvent was prepared to prepare porous microfibers and the fiber morphology was examined as a function of the disk rotation speed in an high speed centrifugal spinning device.
극저온 냉동기에 의해 냉각되는 열사이펀의 과도 열전달 특성에 대한 연구
김영권(Youngkwon Kim),정상권(Sangkwon Jeong) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11
In conduction-cooled superconducting magnets, thermosiphon can be used for interconnecting the cryocooler and the superconducting magnet. The working fluid of the thermosiphon experiences large temperature and pressure variations with its physical properties during the cool-down process. In this study, a cryogenic thermosiphon cooled by a stirling cryocooler is designed, fabricated and tested to investigate on the transient operation characteristics. The temperature and pressure of the working fluid inside the thermosiphon is measured during the whole cool-down process. From the experimental results about thermohydraulic condition of the thermosiphon, modeling of its operation process is carried out to predict thermal performance of the thermosiphon. The appropriate modeling with physical explanation is presented and verified by numerical simulation in this paper.
엔트로피 생성을 고려한 능동형 자기 재생기의 성능특성에 관한 연구
김영권(Youngkwon Kim),정상권(Sangkwon Jeong) 대한설비공학회 2010 대한설비공학회 학술발표대회논문집 Vol.2010 No.6
Internal state of an active magnetic regenerator (AMR) is very comples to investigate since heat pumping mechanism in the active magentic regenerator occurs by transient heat transfer between magnetic refrigerant and oscillating heat transfer medium. In this paper, the performance of active magnetic regenerator is discussed in conjunction with entropy generation. Entropy generation is calculated by one dimensional numerical simulation of a room temperature refrigeration system that utilizes Gd as a magnetic refrigerant. Total entropy generation is composed of conduction and convection heat transfer, pressure drop. The pressure drop is the most dominant mechanism of the entropy generation in the AMR when helium gas is utilized as the heat transfer medium and the convection heat transfer contributes on the axial distribution of entropy generation. The performance and efficiency of the AMR is examined according to various operating conditions.
영구자석 배열을 이용한 능동형 자기재생 냉동기에 대한 실험적 연구
김영권(Youngkwon Kim),정상권(Sangkwon Jeong) 대한설비공학회 2008 대한설비공학회 학술발표대회논문집 Vol.2008 No.2
In this study, a room temperature AMRR (Active magnetic regenerative refrigerator) was fabricated, and experimentally investigated. Gadolinium (Gd) was selected as a magnetic refrigerant with Curie temperature of 293 K. Permanent magnet was utilized to magnetize and demagnetize the AMR. To produce large magnetic field above 1 T in the magnetic refrigeration space, a special arrangement of permanent magnets, so called Halbach array, is employed. Sixteen segments of the permanent magnets magnetized different direction, constitute a hollow cylindrical shaped permanent magnet. The AMR is reciprocated along the bore of the magnet array and produces cooling power. Helium is selected as the working fluid and a helium compressor is utilized to supply helium flow to the regenerator. The fabricated AMRR has different structure and compared to a convectional AMRR since it has an additional volume after the regenerator. Therefore, the cooling ability is generated not only by magnetocaloric effect of magnetic refrigerant but also by the pulse tube effect. It is verified that the cooling ability of AMR is increased due to the magnetocalric effect by the fact that the temperature span becomes 16℃ while the temperature span is only 8℃ when the magnetic field is not applied to the regenerator.
N₂와 CF₄ 혼합물을 작동유체로 하는 극저온 열사이펀에 대한 실험적 연구
김영권(Youngkwon Kim),이지성(Jisung Lee),정상권(Sangkwon Jeong),한영희(Younghee Han),정세용(Seyong Jung),박병준(Byungjun Park) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.9
A thermosiphon is utilized as a thermal shunt to reduce the cool-down time of a cryogenic system cooled by a two stage cryocooler. The cool-down time reduction by the thermosiphon is determined by the type of working fluid which is directly related to the operating temperature range of the thermosiphon. A mixed working fluid has a potential to widen the operation temperature range of the thermosipohon. In this study, the thermosiphon using N₂ and CF₄ mixture as the working fluid is fabricated and tested to verify its transient heat transfer performance. The thermosiphon with the mixed working fluid has no noticeable reduction of cool-down time compared with that of the thermosiphon with pure working fluid in this experiment. However, it seems that the thermosiphon with mixed working fluid may have an advantage according to the cooling capacity of a cryocooler, the cooling target temperature and the size of a cooling object.
Manual Transmission Clutch Pre damper 최적화 및 실험적 검증
김영권(Youngkwon kim),길민철(Minchul kil) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5
Recently strong Requirement of high fuel efficiency and low emission regulation bring about the engine downsized and turbocharger implemented in small and compact vehicles. It inevitably makes the isolation of torsional vibration phenomenon in driveline worse and difficult due to the high amplitude of engine excitation. Therefore Manual transmission applications incrementally adopt new strategy of the wide angle pre-damper and CPA or change the strategy from SMF to DMF in even small-size for the efficient damping on torsional vibration at idle or drive mode. When it comes to apply the SMF application, various clutch damper characteristic library test is necessary as the main factor to reduce the torsional vibration, in particular, in case of idle tuning, 2<SUP>nd</SUP> stage pre damper characteristics between cold and hot condition make the tuning more complicated and hard to optimize and lead to more various samples tests. As a result, in order to optimize best characteristic values of pre-damper and reduce variants in idle tuning activity, it is necessarily required to set up theoretical explanation on pre damper filtration and develop efficient test method throughout the verified correlation between Amesim modeling and realistic tests torsional behavior.
불균일계 비누화를 통한 폴리비닐알코올/셀룰로오스 필름 제조
김태영(Tae Young Kim),김미경(Mi Kyung Kim),김진수(Jinsoo Kim),이정언(Jungeon Lee),정재훈(Jae Hoon Jung),김영권(Youngkwon Kim),김태현(Tae Hyeon Kim),염정현(Jeong Hyun Yeum) 한국염색가공학회 2023 韓國染色加工學會誌 Vol.35 No.4
Poly(vinyl alcohol) (PVA) is a common hydrophilic polymer that is synthesized through the saponification reaction of poly(vinyl ester)-based polymers, mostly using poly(vinyl acetate) (PVAc) as a precursor. The heterogeneous saponification reaction of poly(vinyl ester)-based films leads to PVA films with new surface properties. Cellulose acetate (CA), in which the hydroxyl group of cellulose is replaced by an acetyl group, is a typical cellulose derivative capable of overcoming the low processability of cellulose due to strong hydrogen bonding. In this study, P(VAc/VPi)/CA blended films were prepared by the solvent casting, and then PVA/Cellulose blended films with improved surface properties were prepared by heterogeneous saponification. The structural changes caused by heterogeneous saponification were confirmed by FT-IR analysis, where both saponification and deacetylation reactions occurred in the saponification solution. In addition, the surface property changes were analyzed by FE-SEM and contact angle analyses, and the transmittance changes of the modified films were also assessed.