http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
최상규(S. K. Choi),원상희(S. H. Won),정석호(S. H. Chung),차민석(M. S. Cha),송영훈(Y. H. Song) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Characteristics of syngas combustion was studied numerically for various mixing ratios of methane and syngas which was produced by partial oxidization of methane. Ideal case in which CH₄ is completely decomposed into CO and H₂, and the syngas obtained by equilibrium code which contains other species, were compared. For ideal case, the composition of premixture varies almost linearly for reforming rate, while the composition of syngas from equilibrium code varies nonlinearly and does not vary much until the reforming rate of 0.4. When the mixture of ambient temperature was used, as reforming rate increases, flame temperature decreases but laminar burning velocity increases. This inverse trend which is not general is due to the decrease of overall activation energy as reforming rate. The exponential term of the reaction rate which contains the activation energy and temperature shows similar trend to the laminar burning velocity. Lean flammability limit is expanded, and extinction stretch rate of diffusion flame is increased as reforming rate increases. The flame characteristics is more improved for the ideal case, it will be important to reform effectively to achieve better performance of combustor.
정석호(Chung S. H.),원상희(Won S. H.) 한국가시화정보학회 2004 한국가시화정보학회지 Vol.2 No.1
Several visualization techniques of laser diagnostics are presented for combustion phenomena. including Mie scattering for flow, Rayleigh and Raman scattering spectroscopy for major species, laserinduced fluorescence for minor species, and laser-induced incandescence for soot. These techniques have been applied to understand the various combustion phenomena more clearly, including buoyancy-dominant flow system, diffusion flam oscillation, laminar and turbulent lifted flames, flame propagation along a vortex ring, and soot zone characteristics. The usefulness of laser diagnostics on a better understanding of physical mechanism is demonstrated.
교류전기장이 인가된 상태에서 전선을 통해 전파하는화염에 대한 전선직경의 영향
박순호(S. H. Park),임승재(S. J. Lim),권오붕(O. B. Kwon),박정(J. Park),정석호(S. H. Chung) 한국연소학회 2017 한국연소학회지 Vol.22 No.3
An experimental study on spreading flame over electrical wire, which was insulated by Polyethylene(PE) and had different diameters, was conducted with applied AC electric field. The result showed that the flame spread rate decreased in increase of the diameter of insulator at a fixed electric field. The flame spread rate exhibited increase or decrease tendency with applied AC electric field, having three distinct regimes depending on applied voltage and frequency. In each regime, the flame spread rate was characterized by physical parameters of applied electric fields and wire dimensions, and the behaviors could be explained by a thermal balance mechanism.
전기장이 튜브내 예혼합화염 전파속도에 미치는 영향에 관한 연구
류승관(S. K. Ryu),원상희(S. H. Won),차민석(M. S. Cha),정석호(S. H. Chung) 한국연소학회 2006 KOSCOSYMPOSIUM논문집 Vol.- No.-
The effect of electric fields on flame speed has been investigated experimentally by observing propagating premixed flames in a tube for methane/air mixtures. The flame speeds were measured in both the normal and micro gravity conditions to substantiate the measurements. The results show that the flame speeds were enhanced by both the AC and DC electric fields, as the flame approached to the high voltage electrode located on the one end of the tube. The enhancement of flame speed was proportional to the square root of the electric field intensity, defined as the voltage applied divided by the distance of flame from the high voltage electrode, when the electric field intensity is sufficiently large. When the electric field intensity was low, there existed critical intensities, below which the electric fields did not influence the flame speed. This critical electric field intensity correlated well with the flame speed.
층류 예혼합 화염의 화염 날림 현상에 미치는 교류 전기장 효과
김환호(H. H. Kim),김민국(M. K. Kim),정석호(S. H. Chung) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.39
The stabilization of the laminar premixed jet flames has been investigated experimentally by applying the AC electric fields at low frequency which is below 60㎐ in single electrode configuration. The detachment and blow off velocities have been measured by varying the applied AC voltage and frequency. The detachment velocity was decreased with the applied AC electric fields. The normalized velocity was changed linearly with AC voltage. The normalized velocity decreased and increased over certain frequency with AC frequency. Blowoff velocity had minimum value and transition frequency region was observed. Two different regimes were classified within the boundaries of minimum frequency and transition frequency region. In regime L-Ⅰ from 0.1㎐ to minimum frequency, blowoff velocity decreases with the applied frequency and decreasing rate increases. In regime L-Ⅱ from minimum frequency to transition frequency region, blowoff velocity has opposite trend to the regime L-Ⅰ. Ionic wind effect and chemical reaction enhancement are proposed as the possible causes to influence flame stabilization.
[論文] 디젤엔진 흡입과정에서 실린더내의 시뮬레이션Ⅰ.선회하는 축대칭 정상 난류유동계산
강신형(S. H. Kang),김응서(E. S. Kim),정석호(S. H. Chung),송명호(M. H. Song) 한국자동차공학회 1986 오토저널 Vol.8 No.2
A computer program was developed to predict swirling steady aXisymmetric turbulent flows by extending TEACH Code. It was applied to a reciprocating engine cylinder with a intake valve on the flat head. Flows were assumed to be steady and swirling.<br/> Effects of Reynolds number, the valve lift, and the swirl ratio on flow patterns and tubulence were investigated numerically. Flow patterns were reasonably predicted in comparison with experimental results. Length of the recirculation zone was shortened with increasing valve lifts and swirl ratios. Static pressure distributions show maximum value near the reattachement point of the incoming circular jet and minimum value near the maximum width of the valve attached recirculation zone.