http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고범용(B.Y. GO),백연식(Y.S. Baik),이은석(E.S. Lee),이재은(J.E. Lee),허기훈(K.H. Hur) 한국전산유체공학회 2013 한국전산유체공학회 학술대회논문집 Vol.2013 No.5
A control fin is necessary for the flying object in order to satisfy its stability and maneuverability. In general, a tail is selected as a control fin and the control effectiveness of the tail is very important. Therefore, it is required to study the variables which have influence on tail performance. When side jets are located ahead of tails, the flow field around tails has interferences with side jets. So the aerodynamic characteristics of a missile with side jet is different from that of a missile without side jet. In this study, the influences of side jet on the missile aerodynamics are investigated by use of the computational fluid dynamics. The aerodynamic characteristics are found be affected by not only the free stream conditions, e.g. free stream velocity, angle of attack and bank angle but also the jet conditions, e.g. the temperature and gas property of jet.
저속 압축성 유동에서 예조건화 방법을 이용한 수렴성 증진에 대한 연구
이재은(J. E. Lee),박수형(S. H. Park),권장혁(J. H. Kwon) 한국전산유체공학회 2004 한국전산유체공학회 학술대회논문집 Vol.2004 No.-
It is well known that preconditioning methods are efficient for convergence acceleration at compressible low Mach number flows. In this study, the original Euler equations and three preconditioners nondimensionalized differently arc implemented in two dimensional inviscid bump flows using the 3rd order MUSCL and DADI schemes as flux discretization and time integration respectively. The multigrid and local time stepping methods are also used to accelerate the convergence. The test case indicates that a properly modified local preconditioning technique involving concepts of a global preconditioning one produces Mach number independent convergence. Besides, an asymptotic analysis for properties of preconditioning methods is added.
이재은(J. E. Lee),이태규(T. K. Lee),이상곤(S. K. Lee),김병민(B. M. Kim) 한국소성·가공학회 2008 소성가공 : 한국소성가공학회지 Vol.17 No.8
The cross sectional shape of intermediate die is one of important parameters to improve dimensional accuracy of final product in shaped drawing process. Until now, it has been designed by the experience or trial and error of the expert. In this study, the cross sectional shape of intermediate die for spline shape is determined by the electric fields analysis and scale factor method. The result of the electric fields analysis and scale factor method have been compared with that of the expert method. The effects of cross sectional shape on the dimensional accuracy were investigated by using FE-simulation. And then the multi-stage shaped drawing experiments were performed to verify the results of FE-simulation. As a result, the cross sectional shape from the electric fields analysis and scale factor method had the good dimensional accuracy. These two methods can be used for the method to obtain the cross sectional shape of intermediate die in shaped drawing process.