가진 주파수 변화시 예혼합 화염 날림에 관한 실험적 연구

신재익(Jaeik Shin),정찬영(Chanyeong Jeong),윤영빈(Youngbin Yoon) 한국추진공학회 2013 한국추진공학회 학술대회논문집 Vol.2013 No.12

본 연구에서는 보염기가 장착된 덕트형 연소기에 음향 가진을 주었을 때 화염의 날림 현상을 이해하기 위한 실험을 수행하였다. 화염 구조를 관측하기 위한 촬영기법으로는 OH* 자발광이 적용되었다. 연료는 메탄이 주 성분인 도시가스를 사용했으며 연료와 공기의 혼합비율인 당량비를 낮춤으로서 화염 날림이 발생하도록 하였다. 공기 공급 유량, 가진 주파수에 변화를 주며 실험을 하여 화염 날림이 발생하는 당량비를 측정하였다. 실험 조건에 따라 화염 날림 당량비 값이 크게 달랐으며 이러한 당량비 값에 변화를 주는 요인은 보염기 후류의 와류 주파수와 연소기 공진 효과로 판단된다. In this study, blowoff was investigated in a ducted combustor with the bluff body when acoustic excitation was forced. To observe the flame structure, OH radical chemiluminescence was used. Natural gas mainly composed of methane was used as fuel. Lowering the fuel-air equivalence ratio, blowoff were to occur. Equivalence ratio causing blowoff was measured changing air flow rate and frequency. Depending on the experimental conditions, blowoff equivalence ratio was valued very differently. Vortex frequency behind the bluff body and resonance effect in combustor are the main factors that affect the blowoff equivalence ratios.

영상프로브를 이용한 화염 정면 가시화

신재익(Jaeik Shin),진병대(Byoungdae Jin),현동기(Dongki Hyun) 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.12

본 논문은 국방과학연구소 엔진 시험장에 설치된 영상프로브에 대해 다루고 있다. 영상프로브는 엔진의 후단, 디퓨저 상단에 설치되어 있으며 잠만경 모양의 관 형상을 띄고 있어서 페리스코프라 불린다. 페리스코프는 엔진 후단의 열기(2000 °C) 및 연소 생성물 등의 영향을 받아서 파손 위험이 높다. 따라서 CFD 해석을 통해 장치의 냉각 성능을 검증하였다. 또한 시험을 통해 연료 유량에 대한 장치 내부의 온도를 비교하여 장치의 내구성을 확인하였다. 현재의 설계에서 영상프로브를 통하여 화염 형상 및 노즐 제어, 배출 유동의 안정성을 가시적으로 확인 가능하다. This paper describes an imaging probe device installed in ADD engine test facility. The imaging probe is installed at the rear end of the engine and top of the diffuser. The device is so-called periscope because its figure looks like a pipe of periscope. The periscope has a high risk of breakage due to the influence of heat(2000 °C) at the rear end of the engine and combustion products. Therefore, through CFD analysis, we verified cooling performance of the device. Also, through tests, we verified durability of the device by comparing temperature and fuel mass flow rate. In the current design, using imaging probe, we can see flame shapes, control of nozzle, and stability of exhaust flow visually.

고온고압 환경에 노출된 영상장치 내열특성

신재익(Jaeik Shin),안동찬(Dongchan Ahn),조재한(Jaehan Cho) 한국추진공학회 2017 한국추진공학회 학술대회논문집 Vol.2017 No.5

본 논문은 엔진 시험시 엔진의 후단에 설치되어 엔진 내부의 상태를 감시하는 영상장치의 내열 특성에 관한 것으로, 엔진 시험설비에 사용되는 영상프로브 소개 및 개발에 관한 내용을 담고 있다. 엔진 후단의 영상장치는 고온고압 환경에 노출되어 있어서 장치형상 변경 및 냉각수 공급으로 장치의 안정성을 확보해야 한다. 국방과학연구소의 엔진 시험 장치의 후단에 영상프로브가 설치되어 있으며, 내열특성을 반영하여 설계하여 장치의 안정성을 확보하였다. This paper describes the heat resistance characteristics of the imaging device installed in behind the engine due to monitoring the engine condition, and this paper includes the introduction and development of the imaging probe. Because the imaging device which is at the rear end of the engine is exposed to a high temperature and high pressure, the stability of the device should be secured by changing the device shape and supplying cooling water. The imaging probe in ADD engine test facility is installed at the rear end of the engine, and it is designed by reflecting the heat resistance characteristics to ensure the stability of the device.

예혼합 화염 날림 메커니즘에 음향 가진이 미치는 영향에 대한 실험적 연구

신재익(Jaeik Shin),정찬영(Chanyeong Jeong),윤영빈(Youngbin Yoon) 한국항공우주학회 2014 韓國航空宇宙學會誌 Vol.42 No.12

본 연구에서는 보염기가 장착된 덕트형 연소기에 음향 가진을 주었을 때 화염의 날림 현상을 이해하기 위한 실험을 수행하였다. 화염 구조를 관측하기 위한 촬영기법으로는 OH* 자발광이 적용되었고 POD (Proper Orthogonal Decomposition) 알고리즘을 이용하여 이미지를 분석하였다. 연료는 메탄이 주 성분인 도시가스를 사용했으며 당량비를 낮춤으로써 화염 날림이 발생하도록 하였다. 공기 공급 유량, 가진 주파수 및 음압에 변화를 주며 실험을 하여 화염 날림이 발생하는 당량비를 측정하였다. 실험 조건에 따라 화염 날림 당량비 값이 크게 달랐으며 이러한 당량비 값에 변화를 주는 요인은 보염기 후류의 와류 주파수와 연소기 공진 효과의 영향으로 판단된다. In this study, blowoff was investigated in a ducted combustor with the bluff body when acoustic excitation was forced. To observe the flame structure, OH radical chemiluminescence was used and the image was analyzed by using POD (Proper Orthogonal Decomposition) algorithm. Natural gas mainly composed of methane was used as fuel. Blowoff occurred when the equivalence ratio was reduced. Equivalence ratio causing blowoff was measured by changing air flow rate, excitation frequency and sound pressure. Blowoff equivalence ratio was varied depending on the experimental conditions. Vortex frequency behind the bluff body and resonance effect in combustor are the main factors that affect the blowoff equivalence ratios with the excitation.

엔진 배기가스 냉각장치 성능분석

신재익(Jaeik Shin),김명완(Myoungwan Kim),장경우(gyeongwoo Jang) 한국추진공학회 2020 한국추진공학회 학술대회논문집 Vol.2020 No.11

서비스지향성, 서비스품질, 이미지, 고객만족, 행동의도 간의 관계

정기한(Kihan Chung),신재익(Jaeik Shin) 한국인터넷전자상거래학회 2015 인터넷전자상거래연구 Vol.15 No.3

We performed a study to investigate the relationship among service orientation, service quality, image, customer satisfaction, and behavioral intention in a local festival. Appropriate measures were developed with previous studies and a survey targeting 175 respondents who have experienced the festival was conducted. The results confirmed that service orientation has positive impacts on process quality and outcome quality of service quality. Service quality has positive impacts on festival image and customer satisfaction. However, festival image is not associated with customer satisfaction. Festival image and customer satisfaction have positive impacts on behavioral intention. In addition, service orientation has indirect positive impacts on festival image, customer satisfaction, and behavioral intention through service quality. Thus, it is identified that service orientation and service quality play a critical roles in enhancing behavioral intention. The managers of a local festival should focus on service orientation and service quality.

모바일 학습에서 자기효능감이 행동의도에 미치는 영향에 관한 연구

성행남(Haengnam Sung),신재익(Jaeik Shin) 한국인터넷전자상거래학회 2015 인터넷전자상거래연구 Vol.15 No.4

The purpose of this study is to investigate the relationship among mobile self-efficacy, performance expectancy, effort expectancy, social influence, and behavioral intention of mobile learning, which is based on the Unified Theory of Acceptance and Use of Technology(UTAUT). It is also to examine the moderating effects of facilitating conditions. Appropriate measures were developed and tested on 268 respondents of Gyeongnam province in South Korea with a cross-sectional questionnaire survey. The path relationships of the research model was analyzed by structural equation modeling(SEM) using AMOS 18.0. The results revealed that firstly, self-efficacy has positive effects on performance expectancy, effort expectancy, and social influence. Second, performance expectancy, effort expectancy, and social influence have positive effects on behavioral intention. Performance expectancy has the most impact on positive behavioral intention. Third, the difference in the Chi-square between the moderating model and the constrained model is also significant. Managers of mobile learning should focus on mobile self-efficacy and facilitating conditions to enhance behavioral intention.

블로그 정보 특성이 신뢰의 전이와 구매의도에 미치는 영향

오재신(Jaesin Oh),신재익(Jaeik Shin) 한국인터넷전자상거래학회 2017 인터넷전자상거래연구 Vol.17 No.4

This study performed to investigate the influences of Blog information characteristics on information trust and product trust. In particular, this study tried to analyze the effect of information trust on product trust in order to clarify the effect of trust transfer. Also, we tried to clarify the relationship between information reliability and product trust on purchase intention. The critical purpose of this study is to develop a successful Blog marketing strategy. Preferentially, the Blog information characteristics’ were categorized as three factors; vividness, usefulness, and neutrality. A total of 253 questionnaires were collected from respondents in Korea, some questionnaires were eliminated due to missing data, resulting in a final sample of 225 respondents. The major findings indicate that first, vividness, usability, and neutrality, which are considered as information characteristics, have a significant effect on information trust. However, only neutrality has a significant effect on product trust. And information trust has a significant effect on product trust, thus showing the effect of trust transfer. Finally, it was confirmed that information trust and product trust have a significant effect on consumers’ purchase intention.

보염기를 사용한 예혼합 화염에서 외부 가진에 따른 희박 화염 날림의 특성에 관한 연구

정찬영(Chanyeong Jeong),신재익(Jaeik Shin),윤영빈(Youngbin Yoon) 한국연소학회 2013 KOSCOSYMPOSIUM논문집 Vol.2013 No.12

전통시장의 청년몰에서 고객충성도에 대한 영향요인

팽현호(Hyeonho Paeng),신재익(Jaeik Shin) 한국경영학회 2023 한국경영학회 통합학술발표논문집 Vol.2023 No.8