http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
R134a 터보냉동기용 원심압축기의 성능특성에 관한 수치해석적 연구
이경용,최영석,박운진,Lee, Kyoung-Yong,Choi, Young-Seok,Park, Woon-Jean 한국유체기계학회 2004 한국유체기계학회 논문집 Vol.19 No.4
In this study, the overall performance and the local flow field of the centrifugal compressor with the refrigerant HFC-l34a were numerically studied using CFX-TASCflow. The thermodynamic and transport properties of the refrigerant gas were modeled by REFPROP which is NIST refrigerant properties database. The impacts of a grid qualify, discretization scheme, turbulent model and interaction between a impeller and a cascade diffuser were analyzed comparatively. The results were compared with experimental data and 1-D design results using COMPAL and agreed well with others. The numerical method and data obtained in this study can be applied to the design and modification of centrifugal compressors with real gases
PEM 연료전지용 Bipolar Plate의 변화단면 유로에 대한 CFD 해석
양동진(Yang, Dong-Jin),박운진(Park, Woon-Jean) 한국신재생에너지학회 2007 신재생에너지 Vol.3 No.3
A flow channel model of a bipolar plate with varying cross-sectional area was newly designed for improving performance and efficiency of a PEM fuel cell stack. As a result, the varying cross-sectional area model showed poor uniformity in velocity distribution, however, maximum velocity in the flow path is about 30% faster than that of the uniform cross-sectional area model. The proposed varying cross-sectional area model is expected to diffuse operating fluids more easily into diffusion layer because it has relatively higher values in pressure distribution compared with other flow channel models. It is expected that the implementation of the varying cross-sectional area model can reduce not only the mass transport loss but also the activation loss in a PEM fuel cell, and open circuit voltage of a fuel cell can thus be increased slightly.
사이드 채널형 링블로워의 임펠러 내부 유로에 따른 성능변화 분석
이경용(Kyoung-Yong Lee),최영석(Young-Seok Choi),정경호(Kyung-Ho Jeong),박운진(Woon-Jean Park) 한국유체기계학회 2011 유체기계 연구개발 발표회 논문집 Vol.2011 No.11
This study analyzed performance changes by an inner flow path of impeller groove for side channel type ring blower using CFD. Two models have the same side channel and clearance while one has an inner flow path and the other doesn’t. To analyze the performance change of a ring blower, overall performance and local flow field were analyzed. For the overall performance, pressure increase and impeller torque were checked under the design flow condition. Under the design flow condition, pressure increase was greater for the model with the inner flow path. The model with the inner flow path showed improved efficiency because the area subject to torque decreased due to the creation of inner flow path. To analyze local flow field, a section was created from the representative location of each impeller groove toward the direction of radius. Inner channel pressure distribution depending on the rotation direction shows that the model with the inner flow path has pressure equilibrium of working fluid through the inner flow path. Velocity distribution of inside impeller groove shows that flow field was coupled and appeared to form an inner wall where the flow field was stabilized.
R134a 터보냉동기용 원심압축기의 익단간극이 성능특성에 미치는 영향에 관한 수치해석적 연구
이경용(Kyoung-Yong Lee),최영석(Young-Seok Choi),박운진(Woon-Jean Park) 한국유체기계학회 2003 유체기계 연구개발 발표회 논문집 Vol.- No.-
In this study, the overall performance and the effect of the tip leakage flow of the centrifugal compressor with the refrigerant HFC-134a were numerically studied using CFX-TASCflow. To study the effect of a tip leakage flow, the numerical study of the overall performance of HFC-134a centrifugal compressor with a cascade diffuser was preceded and compared with experimental result. Six different tip clearances were used to consider the influence of a tip clearance on performance. The tip leakage flow was illustrated for qualitative discussion. The results obtained in this study can be applied to the determination of the cold clearance.
대형 차량 후류 속을 주행하는 Cube형 경차의 항력에 대한 연구
이호원(Ho Won Lee),나선근(Sun Geun Na),김윤제(Yun Je Kim),김창엽(Chang Yup Kim),최지원(Ji Won Choi),이경용(Kyung Yong Lee),박운진(Woon-Jean Park) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11
In this research, to analyze the slipstream effect of a compact car in the wake of a large vehicle, flow visualization for the reduced vehicle models in the wind tunnel and flow analysis by means of CFD are carried out. Both results of flow visualization experiment as well as CFD simulation are then analyzed and compared. As a result, the slipstream effect due to the decrease of relative pressure in the wake of a leading vehicle are experimentally verified at a cubic compact car behind a large vehicle in the operating condition of . Therefore it is expected the drag reduction can be achieved by means of slipstreaming technique between a large blunt vehicle and a cubic compact car in the highway transportation.