http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
가솔린 엔진의 연료분사시기가 희박연소한계에 미치는 영향에 관한 연구
엄인용(I. Y. Ohm),정경석(K. S. Jeong),정인석(I. S. Jeung) 한국자동차공학회 1996 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1996 No.6_2
The effects of fuel injection timing on lean misfire limit has been investigated in a sequential MPI SI engine. To investigate the interaction of injection timing and intake flow characteristics, so called axial stratification phenomena, 4 different swirl inducing intake ports have been tested in single cylinder engine test bench. And 2 kinds of fuel, gasoline and compressed natural gas(CNG), were used to see the effect of liquid fuel vaparization. Result shows that the combination of port swirl ratios and injecton timimg governs the lean misfire limit and lean misfire limit envelopes reamain alomost same for a given swirl ratios regardless of engine speed. It is also found that two phase flow has some effects on lean misfire limit ,i.e. axial stratification.<br/>
특성곡선 해법 설계 극초음속 노즐의 경계층 보정 및 레이놀즈 수 효과
김소연(S.-Y. Kim),최정열(J.-Y. Choi),김성돈(S.-D. Kim),정인석(I.-S. Jeung),이종국(J.-K. Lee) 한국추진공학회 2014 한국추진공학회 학술대회논문집 Vol.2014 No.5
특성곡선 해법을 이용하여 출구 마하수가 6과 7인 극초음속 풍동의 노즐을 설계하였다. 설계된 노즐에 대하여 마하6에서는 4×104에서 4×107, 마하 7에서 4.6×104에서 4.6×106 범위의 레이놀즈수에서 전산유체역학 해석을 통한 경계층 예측을 수행하였다. 해석 결과로부터 경계층 속도가 벽면 위 최대 속도의 95%되는 두께를 선택하여 노즐 형상을 보정하였다. 점성 유동 해석을 다시 수행하여 보정 결과를 확인한 결과, 보정된 노즐은 설계 마하수를 잘 만족함을 확인할 수 있었다. Hypersonic wind tunnel nozzles are designed by the method of characteristics for exit Mach number 6 and 7. The boundary thicknesses of the nozzles were estimated for Reynolds numbers from 4×104 to 4×107 at Mach 6, and 4.6×104 to 4.6×106 at Mach 7 through the CFD analyses. The nozzle contours were corrected by using the boundary layer thickness defined as the 95% of the maximum speed above the wall. Viscous flow analyses for the revised configurations confirm that the exit Mach number with boundary layer correction satisfy the requirement of the design Mach number.
DES를 이용한 초음속 유동내 수직 연료분사 유동의 비정상 3차원 해석
원수희(S.H. Won),문성영(S.Y. Moon),정인석(I.S Jeung),최정열(J.Y. Choi) 한국전산유체공학회 2008 한국전산유체공학회 학술대회논문집 Vol.2008 No.-
Unsteady three-dimensional flowfields generated by transverse fuel injection into a supersonic mainstream are simulated with a DES turbulence model. Comparisons are made with experimental results in term of the temporal eddy position and eddy formation frequency. The vorticity field around the jet exit is also analyzed to understand the formation mechanism of the jet vortical structures. Results indicate that the DES model correctly predicts the convection characteristics of the large scale eddies. However, it is also observed that the numerical results slightly overpredict the eddy formation frequency. The jet vortical structures are developed from the competing vortices in the recirculation region of upstream boundary.