고체 로켓 추진기관에서 실리카/페놀릭 열반응 해석 연구

서상규(Sangkyu Seo),함희철(Heecheol Hahm),강윤구(Yoongoo Kang) 한국추진공학회 2017 한국추진공학회 학술대회논문집 Vol.2017 No.5

본 논문에서는 고체 로켓 추진기관에서 내열재 및 단열재로 사용되는 실리카/페놀릭 복합재료의 열반응을 고려한 열전도 수치해석을 수행하였다. 고체 로켓 추진기관의 연소 중 실리카/페놀릭의 삭마와 열분해 과정을 고려한 열전도 해석을 위해 1차원 유한차분법을 이용하여 계산을 수행하였다. 노즐벽에서의 경계조건은 대류열전달계수를 고려하였으며, 이는 적분방정식을 이용하여 계산하였다. 삭마두께 및 숯깊이 해석결과는 목삽입재 평가 모터인 TPEM-10을 이용한 시험결과와 비교분석하였으며, 잘 일치하는 것을 확인할 수 있었다. In this paper, the numerical analysis for heat conduction of silica/phenolic composite material, which is used for solid rocket nozzle liner or insulator, was conducted. 1-D Finite Difference Method for the analysis of silica/phenolic during the firing of solid rocket motor was used to calculate the heat conduction considering the surface ablation and the thermal decomposition. The boundary condition at the nozzle wall took into account the convective heat transfer, which was obtained by integration equation. The numerical results of the surface ablation and char depth were compared with the results of test motor that is TPEM-10. It was found that the result of calculation is favorably agreed with the thermal response of test motor.

고체 로켓 추진기관에서 실리카/페놀릭 열반응 해석 연구

서상규(Sangkyu Seo),함희철(Heecheol Hahm),강윤구(Yoongoo Kang) 한국추진공학회 2018 한국추진공학회지 Vol.22 No.4

In this paper, the numerical analysis for heat conduction of silica/phenolic composite material, used for solid rocket nozzle liners or insulators, is conducted. A 1-dimensional finite difference method for the analysis of silica/phenolic during the firing of a solid rocket motor is used to calculate heat conduction, considering surface ablation and thermal decomposition. The boundary condition at the nozzle wall, considering the convective heat transfer, is obtained via integration equations. The numerical results of the surface ablation and char depth are compared with the results of a TPEM-10 test motor, finding that the result of calculation agrees with the thermal response of the test motor.

근현대기 일본문법서에 나타난 "문법"의 쓰임과 개념의 추이

윤영민 ( Young Min Yun ),서상규 ( Sangkyu Seo ) 연세대학교 언어정보연구원(구 연세대학교 언어정보개발원) 2016 언어사실과 관점 Vol.38 No.-

As a basic study to ponder linguistic negotiation with Japanese in a process to establish and systematize modern Korean grammar, this thesis examines development of advent, use, and concept of a term ‘grammar’ targeting books related to modern grammar published in Japan. About the effect of Japanese grammar on the process to establish and systematize modern Korean grammar, various tries through Korean grammar book and study material written by Maema Kysaku, Takahashi Tohoru, Yakushiji Jiro reflecting ‘Compromise Grammar’ of Otsuki Fumihiko and ‘Yamada Grammar’ of Yamada Yoshio after Hoseko Sigekatsu and Shimai Hiroshi who are early influenced by Western grammar from late in the 18th century to the early 20th century penetrating the time of enlightenment are seen here and there. This thesis introduces Japanese materials of ‘A Study Database of Modern Korean Grammar Formation History’ as an extension line of Oi Hideaki and Seo Sangkyu(2015). Based on this, the researcher adds materials that are additionally investigated and analyzed after Oi Hideaki and Seo Sangkyu(2015), so collects ‘grammar’ in Japanese and terms related to this grammar, so looks back use and concept of the term ‘grammar’ of use aspect and concept.

1;1- 2;6세 한국 아동의 표현어휘 연구

최은희(Eunhee Choi),서상규(Sangkyu Seo),배소영(Soyoung Pae) 한국언어청각임상학회 2001 Communication Sciences and Disorders Vol.6 No.1

본 연구는 부모보고서를 통해 1;1- 2;6세 한국 아동이 각 연령단계에서 사용하는 어휘의 목록과 평균어휘수를 조사하고, 평균어휘수가 집단간 차이가 있는지 알아보았다. 또한 수집된 자료를 분석하여 한국 아동의 초기 어휘습득이 언어보편성가설과 언어특정성가설 중 어느 것을 지지하는지 살펴보았다. 연구대상은 서울·경기 지역에 거주하는 1;1- 2;6세 아동 180명을 대상으로 하였는데, 3개월 간격으로 각 연령집단별로 30명씩, 남녀비율은 1:1이었다. 횡단연구 결과, 연령집단별로 평균어휘수가 1;1- 1;3세에 13개, 1;4- 1;6세에 54개, 1;7- 1;9세에 166개, 1;10- 2;0세에 256개, 2;1- 2;3세에 326개, 2;4- 2;6세에 488개로 나타났다. 또한 생활연령 집단과 언어연령 집단별 명사와 술어의 산출율을 살펴보았을 때 모든 연령집단에서 명사의 비율이 50% 이상으로 술어의 비율보다 훨씬 높게 나타났다. 종단연구 결과 아동별로 명사의 산출율이 술어의 산출율 보다 커 50% 이상을 유지하고 있었다. Choi & Gopnik(1995)의 명사, 술어 증가 기준을 사용하여 총 어휘수가 100개 이하 아동에게 적용하였을 때도 명사 증가가 동사 증가보다 유의미하게 빠르게 나타났다. 따라서 한국 아동에게도 언어보편성(명사선호성) 가설이 지켜지고 있는 것을 알 수 있었다. The main purpos es of this s tudy ar e to inves tigate the mean number of vocabulary of Korean childr en aged 1;1- 2 ;6, us ing the par ent r epor t , and to examine which hypothes is the ear ly vocabulary acquis ition of Kor ean childr en s uppor ts , either language - univers ality hypothes is or language - specificity hypothes is . One hundr ed and eighty s ubjects , aged 1;1 to 2 ;6, s ectioned in s ix gr oups with age - intervals of thr ee months , par ticipated in the s tudy . We ex amined the mean numbers of vocabulary items and the pr oduction pr opor tions in terms of age incr eas e. The r atio of nouns as agains t that of pr edicates was als o inves tigated. The r es ults showed that noun spur t was fas ter than that of pr edicates . The total number of nouns and their pr opor tions to total wor ds wer e far gr eater than thos e of verbs in all age gr oups. It was als o found that the pr opor tions of nouns wer e mor e than 50% r elative to the pr opor tions of verbs. The r es ults of the s tudy definitely s uppor ted the language - univers ality hypothes is.

연소시간 중 노즐조립체의 열-구조적 거동분석에 관한 연구

노영희(Younghee Ro),서상규(Sangkyu Seo),정승민(Seongmin Jeong) 한국추진공학회 2018 한국추진공학회지 Vol.22 No.4

A great deal of difficulty is encountered in the thermo-mechanical analyses of nozzle assemblies for solid propellant rocket motors. The main issue in this paper is the modeling of the boundary conditions and the connections between the various components-gaps, relative movements of the components, contacts, friction, etc. This paper evaluates the complex phenomena of nozzle assemblies during burning time with co-simulations that include fluid, thermal surface reaction/ablation, and structural analysis. The validity of this approach is verified via comparison of analysis results with measured strains.

Utterance-Level Word Class Characteristics in Normal Elderly Women

김지영(Jiyoung Kim),서상규(Sangkyu Seo),조성래(Sung-Rae Cho),김향희(HyangHee Kim) 한국언어청각임상학회 2014 Communication Sciences and Disorders Vol.19 No.3

배경 및 목적: 자발화에 나타난 품사를 살펴봄으로써 화자의 표현 언어를 문법적으로 분석할 수 있다. 노년층과 청년층의 품사 산출 양상을 비교하여, 노년층의 발화 특성을 분석하고자 하였다. 방법: 노년층 35명, 청년층 35명에게 자발화를 수집하였고, 산출한 품사는 형식, 기능, 의미에 따라 나누었다. 이에 따른 품사의 빈도수와 유형수, 어휘다양도의 수치를 나타내었다. 결과: 형식적 분류에서 노년층은 청년층에 비해 빈도수와 유형수 모두 가변어를 적게, 불변어를 많이 사용하였고, 가변어의 어휘다양도는 노년층이 낮았다. 기능적 분류에서 노년층은 체언에서는 빈도수를 많이 사용하였으나, 용언에서는 빈도수와 유형수 모두 적게 사용하였고, 용언의 어휘다양도는 노년층이 낮았다. 수식언은 빈도수를 적게, 독립언은 빈도수를 많이 산출하였다. 의미적 분류의 품사는 노년층이 대명사에서 빈도수와 유형수 모두 많이 산출하였고, 동사에서는 빈도수를 많이 사용하였지만, 동사의 어휘다양도는 낮게 나타났다. 형용사와 부사에서는 노년층이 빈도수와 유형수 모두 적게 산출하였다. 추가분석으로, 용언의 양상을 관형적용법, 서술적용법으로 나누었다. 노년층은 청년층에 비해 서술적용법의 사용 비율이 더 높았다. 논의 및 결론: 노년층은 청년층과 비교하여 품사 산출 양상이 달라지는 것을 밝혔다. 품사의 세 가지 분류방법을 통해 여러 측면에서 특징을 분석하였고, 빈도수, 유형수, 어휘다양도를 측정하여 양적 측면뿐 아니라 질적 측면에서 발화 특성을 살펴보았다. Objectives: Expressive language ability can be analyzed grammatically by examining the production of word classes. This study aims to analyze the characteristics of elderly people's utterances by looking at word classes in spontaneous speech. Methods: Spontaneous speech from 35 young females and 35 elderly females was collected. Word classes were divided by three criteria (form, function, and meaning). The real usage frequency of each instance of a word class (token) and the frequency of occurrence of each word class (type), type-token ratio (TTR), were calculated. Results: For the form category, in both type and token count, the use of inflected words was lower among elderly people, while the use of uninflected words was higher. TTR of inflected words was lower in elderly people. For the functional category, the tokens for substantives were higher among elderly people, while both the types and tokens of inflectional words were lower. For the semantic category, the tokens for verbs were higher but TTR of verbs was lower. The tokens and types for adjectives were both lower among elderly people. Additional experiments showed that the predicative use of inflectional words is more frequent than the attributive use among the elderly. Conclusion: This analysis was conducted with three word class criteria to find various speech characteristics. Further study on word class in language production needs to be conducted while considering factors, such as education and gender.

로켓 추진기관용 C/SiC 내열부품 개발

김연철(Yunchul Kim),서상규(Sangkyu Seo) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5

고체 및 액체 로켓 추진 기관 내열부품으로 사용하기 위하여 C/SiC 복합 재료를 LSI(Liquid Silicon Infiltration) 공법으로 개발하였다. 조성비에 따른 내열 특성은 아크 플라즈마, 초음속 토치 시험으로 평가하였으며 H₂O 및 CO₂ 산화에 의한 유효 삭마식을 제시하였다. 연소시험을 통하여 고체 및 액체 추진기관용 노즐목 삽입재, 확대부 내열재 및 연소실 내열부품 등 다양한 형상으로 제작이 가능함을 확인하였으며 높은 내삭마 성능과 열구조 성능이 입증되었다. C/SiC composites were developed by LSI (Liquid Silicon Infiltration) method for use as heat-resistant parts of solid and liquid rocket propulsion engines. The heat resistance characteristics according to the composition ratio (carbon / silicon / silicon carbide) were evaluated by specimen test through arc plasma, supersonic torch test. The ablation equation for oxidation reactions was presented. Through the combustion test it was verified that various shapes such as nozzle insert, exit cone and combustion chamber heat resistant parts for rocket propulsion can be manufactured and proved high ablation performance and thermal structure performance.

탄성내열재 배합 환경에 따른 내열 성능 변화에 관한 연구

김남조(Namjo Kim),서상규(Sangkyu Seo),강윤구(Yoongoo Kang),고청아(Cheongah Go) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5

고온 · 고압의 연소가스로부터 구조물을 보호하는 탄성내열재는 재료 조성 및 열환경 조건에 따라 열반응에 차이를 보인다. 본 논문에서는 탄성내열재의 배합 환경 변화에 따른 열반응 특성을 비교하였다. 탄성내열재의 내열 성능 시험은 내열고무성능평가장치(TPREM)를 이용하였으며, 연소실 압력 1,000 psig에서 연소가스속도를 각각 20 m/s과 100 m/s로 시험하였다. 연소실 압력-시간 선도, 재료 내부 온도-시간 선도, 탄성내열재 시편의 잔류두께 및 열파괴두께를 획득하였다. 배합 환경에 따른 탄성내열재의 내열 성능은 유사하였다. The elastomeric insulators that protect from high-temperature and high-pressure combustion gases differ in the thermal response depending on the composition of materials and thermal environment conditions. In this paper, thermal reaction characteristics of elastomeric insulators in different mixing environments was compared with each other. The tests for thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities were tested at 20 m/s and 100 m/s at the 1,000 psig in chamber pressure, respectively. The pressure-time curve of chamber, materials internal temperature-time curve, residual thickness and thermal destruction depth of test specimens were obtained. After the tests, results show that thermal protection performance of elastomeric insulators by mixing environments was similar.

탄성내열재 배합 환경에 따른 내열 성능 변화에 관한 연구

김남조(Namjo Kim),서상규(Sangkyu Seo),강윤구(Yoongoo Kang),고청아(Cheongah Go) 한국추진공학회 2019 한국추진공학회지 Vol.23 No.1

The thermal response of elastomeric insulators used as protection against high-temperature and high-pressure combustion gases varies depending on their composition and thermal environment conditions. In this paper, the thermal response characteristics of elastomeric insulators in different mixing environments were compared. Tests to determine thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities of 20 ㎧ and 100 ㎧ were tested at a chamber pressure of 1,000 psig. The pressure time curve of the chamber, the temperature time curve of the internal materials, the residual thickness and the thermal destruction depth of the test specimens were obtained. The results showed that the thermal protection performance of elastomeric insulators in different mixing environments was similar.

흑연 노즐목 삽입재의 삭마율에 미치는 영향 인자 연구

함희철(Heecheol Hahm),강윤구(Yoongoo Kang),서상규(Sangkyu Seo) 한국추진공학회 2017 한국추진공학회지 Vol.21 No.4

The ablation characteristics of graphite nozzle throat insert was analyzed for the use in solid rocket propulsion system. The propulsion system was composed of three types of conventional nozzles, such as De-Laval type, blast tube type, and submerged type. Various kinds of propellants were used in ten kinds of propulsion system that had different shapes with each other. Total forty eight tests were performed. From the results of the analysis, it was found that the ablation rate was increased for the higher average chamber pressure and the higher oxidizer mole fraction. A useful correlation for nozzle throat ablation rate was developed in terms of the chamber pressure, oxidizer mole fraction, and throat size. The calculated ablation rates from the correlation showed agreement within ± 0.10 mm/s with the experimentally determined values.