준충류 근사를 이용한 수소-공기 비예혼합화염의 질소산화물 생성예측

김성룡,정인석,윤영빈,Kim, Seong-Lyong,Jeung, In-Seuck,Yoon, Young-Bin 한국연소학회 1999 한국연소학회지 Vol.4 No.1

A Numerical Analysis of NOx production in Hydrogen-Air flame is performed using the quasi-laminar reaction modelling. As results, in low global strain rate region, $U_F/D_F\;{\leq}\;50,000$, the quasi-laminar reaction modelling reproduces the experimentally observed EINOx half power scaling that the ratio of EINOx and flame residence time, $L_f^3(D_F^2U_F)$, is proportional to the square root of global strain rate. Thus, it suggests that turbulence-chemistry interaction has a minor impact on the trend of NOx production in low global strain rate region. However, the quasi-laminar reaction modelling predicts the higher temperature and NOx than experimentally observed. This overprediction may be due to the lack of radiation and quasi-laminar reaction modelling.

공기를 이용한 축소형 4노즐 클러스터드 엔진 저부 유동의 CFD 해석 검증

김성룡(Seong-Lyong Kim),김인선(Insun Kim) 한국추진공학회 2011 한국추진공학회 학술대회논문집 Vol.2011 No.11

공기를 이용한 축소형 4 노즐 클러스터드 엔진 저부 유동에 대한 CFD 해석을 수행하여 격자 및 차분법, 난류 모델에 따른 비교를 수행하였다. 해석 결과 Roe나 AUSM 차분에 따른 차이는 발견되지 않았으나, 난류 모델에 따른 차이는 적지 않은 것으로 나타났다. 본 연구의 결과로는 Spalart-Allmaras 1 방정식 난류 모델이 SST k-w 모델에 비하여 경향성을 잘 맞추는 것으로 드러났다. 엔진 저부의 마하수, 압력 속도 등의 변화를 분석하면, 엔진과 엔진 사이의 외부 노출 공간에서 유동의 목을 형성하는 것은 아닌 것으로 보이고 이는 노즐과 노즐 사이의 공간이 목을 형성한다는 일부 해석적 이론에서 가정한 상황과 약간 다른 것이다 CFD simulation has been conducted on a small scaled 4 nozzle clustered engine operating with air. In the present paper, the effects of grid size, turbulence models, flux difference methods have been compared. The results show that the base flows are somewhat different as the turbulence models, while Roe and AUSM flux differences produced almost the same results. Spalart-Allmaras turbulence model produces more accurate results rather than famous SST k-w model. The calculated Mach number and pressure profile in the engine base reveal the complex base flow structure, which is somewhat different from the generally estimated flow fields.

예조건화 시간차분을 통한 화학반응유동의 효율적 계산

김성룡(Seong-Lyong Kim),정인석(In-Seuck Jeung),최정열(Jeong-Yeol Choi) 한국연소학회 1999 KOSCOSYMPOSIUM논문집 Vol.- No.-

고려 중기 선 사상과 문학 사상의 관련 양상 연구

김성룡 ( Kim Seong Lyong ) 한국한문학회 2003 한국한문학연구 Vol.0 No.32

근사 화학반응 자코비안을 이용한 화학반응 유동해석

김성룡(Seong-Lyong Kim),최정열(Jeong-Yeol Choi),정인석(In-Seuck Jeung),박양호(Yang-Ho Park) 한국전산유체공학회 1999 한국전산유체공학회 학술대회논문집 Vol.1999 No.-

The Equations of Chemical kinetics are very stiff, which forces the use of an implicit scheme. The problem of implicit scheme, however, is that the jacobian must be solved at each time step. In this paper, we examined the approximate chemical jacobian methods such as Gauss-Seidel, Jacobi partial jacobian and diagonalized jacobian that can be stable without full jacobian, We show that Gauss-Seidel jacobian method is stable and accurate as well as full jacobian and that this is more efficient in supersonic combustion problem about 20% than the full jacobian method with same accuracy.

냉각수 분사에 따른 일차원 열평형 관유동 해석 코드 개발

김성룡(Seong-Lyong Kim) 한국추진공학회 2023 한국추진공학회지 Vol.27 No.5

A 1-D numerical code for spray cooling of a duct flow was developed based on the conservation equation including momentum. The code can consider the effects of temperature and velocity of the condensed water, and the accuracy was verified by compared with the results of AEDC Analysis[1] and Test[8]. Through the cooling water analysis, it was revealed that the cooling water did not significantly change the flow pressure, but the temperature of the cooling water was important for noise reduction and the water vapor removal in the flow. The present code validated the previous results of Im et al.[2] and showed the importance of pressure treatment. This code can be used for the design of high altitude simulation test facilities for rocket engines.

이중 텍스트의 시학과 중층 독해의 이론에 관한 연구

김성룡 ( Kim Seong Lyong ) 한국문학교육학회 2003 문학교육학 Vol.12 No.-

In this article, I search for the aesthetics of Dual Text, for example, Kajeon[假傳], Wuwha[寫話], Wueon[寫言]. As the text dually constructed so the reader should comprehend its dual meaning structure. There are two kinds of dual meaning structure, Kajeon text is the one and the Wuwha is the other one. Kajeon text can be translated into two texts. When we read it, we can comprehend a person s life, his birth, his youth, his achievement etc. However at the same time we can read it as a sort of the characteristics of a thing, its use, its distinctive quality and its value etc. We can comprehend the proper noun in this text two ways; one is as a proper noun, the other as a common noun. The aesthetics of the Kajeon is that dual comprehension. Kosa[故事] is also the key rhetoric of Kajeon text. We can comprehend that Kosa also two ways; one is the word as it is, and the other is the background of the word. But the later is not the signifie of the former. For example, the word Cheong-ju-jong-sa[淸州從使] evokes two signifiant, one is an official of the district of Chengju, and the other is good wine. It is also the aesthetics of the Kajeon text. Personification is also the key rhetoric of Kajeon text. But the rhetoric of personification is not a plane one. By the personification, the narrator can present an invisible thing as an visible one. Especially the Simsong-Kajeon [心性假傳] is a typical one. Of course we can also know that Kajeon and Wuwha have dual meaning. But the tactics of writing are defferent each other. The tactics of writing Kajeon is mainly dependent on dual sigdiant, but the tactics of writing Wuwha is mainly dependent on dual signitie. It could be shown as follows.

상세 화학반응 모델을 이용한 발사체 터빈 배기가스의 이차연소 해석의 축대칭 해석

김성룡(Seong-Lyong Kim),김인선(Insun Kim) 한국추진공학회 2011 한국추진공학회 학술대회논문집 Vol.2011 No.11

상세 화학반응 모델을 이용하여 3차원 터빈 배기가스 유동을 2차원 축대칭 유동으로 가정하여 해석하였다. GRI의 35 화학종 217 단계의 상세 모델과 메탄 반응만을 간략화시킨 11화학종 15단계 모델을 적용하여 비교하였다. 메탄 화학반응을 적용한 결과 저부에서 터빈 배기가스의 이차 연소가 나타났고 터빈 배기 노즐이 없는 경우에 비하여 온도가 600K 정도 더 높게 나타났다. 실제 3차원 문제에서는 국부적인 온도는 더 높을 수 있음을 의미한다. 화학 반응 모델에 따라 저부에서의 연소 영역과 화학종 분포도 약간 다르지만 저부에서의 이차 연소는 모두 포착하였다. 다만 간략화된 모델인 경우 엔진 플룸의 구조에 약간의 영향을 주는 것을 관측된다. 3 dimensional turbine exhaust gas flow was simplified to an axisymmetrical flow and calculated with detailed chemistry models. GRI 35 species-217 reaction step model and simplified 11 species 15 reaction model was applied to the secondary reaction of the turbine exhaust gas and compared. All the model captured the secondary combustion on the base region, and the temperature was 600K higher than that without turbine exhaust gas. This means the local temperature of the base can be higher in the case of real 3 dimensional flow. The simplified model show the similar results to the GRI detailed chemistry model although the former affected the engine plume structure slightly

냉각수 분사에 따른 일차원 열평형 관유동 해석 코드 개발

김성룡(Seong-Lyong Kim) 한국추진공학회 2023 한국추진공학회 학술대회논문집 Vol.2023 No.5

입자 특성에 따른 고체모터 플룸 이상유동 해석

김성룡(Seong-Lyong Kim),김인선(Insun Kim) 한국항공우주연구원 2010 항공우주기술 Vol.9 No.1

알루미나 입자가 포함된 KSLV-I KM 고공 플룸 유동을 연소실에서 노즐 출구의 고공 팽창과정을 해석하였다. 알루미나 입자 및 플룸 가스의 물성치 및 분포를 달리하여 해석한 결과 연소가스 비열비를 1.2로 알루미나 입자의 직경 분포를 7가지로 가정하면 노즐 내부 유통 특성이 평형유통 해석 결과와 비교적 일치하였다. 입자의 팽창각은 가스유동보다 작으며 입자 직경이 클수록 팽창각은 더 작았다. 알루미나 입자의 광학 열물성을 변화시키며 KM TVC 분배기 위치의 복사열을 계산한 결과 알루미나 입자의 방사율이 0.1일 때 비행시험 결과와 비슷한 수준을 예측하였다. KSLV-I KM plume including alumina particle has been studied using the continuum solver. Alumina particles are assumed to have 7 different diameters, and the specific ratio of the plume gas is assumed to be 1.2, with which the internal nozzle flow characteristics are similar to those of the chemically equilibrium analysis results. The results showed that the expansion angle of the particles is smaller than that of the gas phase, and that the big sized alumina particles are gathered in the plume core and the expansion angles of the big sized paticles are smaller than those of the light particles. When the emissivity of the particles are assumed to be 0.1, the radiative heat flux is equivalent to those Treasured during the flight test of KSLV-I.