• 대한화학회지
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• 제59권4호
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• pp.296-307
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• 2015

이 연구의 목적은 초의 연소과정에서 기체 농도를 측정할 수 있는 실험을 개발하고, 그 적용 효과를 알아보는 것이다. 이 연구를 위하여 성별, 교사 경력, 6학년 교수경험, 2007개정 6학년 교수 경험 등을 고려하여 15명의 초등교사들을 선정하였다. MBL을 이용한 이 실험은 아크릴통 안에서 초가 연소하는 동안 산소와 이산화탄소의 농도를 시각적으로 확인할 수 있도록 고안되었다. 이 실험 방법은 다음과 같다. 1) 아크릴 통에 2쌍의 구멍을 만들고, 그 구멍에 2개의 산소 센서와 2개의 이산화탄소 센서를 넣는다. 2) 초를 아크릴통 안에서 연소시키면서 그 변화를 관찰한다. 이 실험은 산소의 농도와 이산화탄소의 농도가 수치로 나타나고 그래프로 그려지므로 기체 농도의 변화를 실시간으로 확인할 수 있다. 이 실험을 적용한 결과, 연소에 대하여 과학적 개념을 가지고 있지 않았던 많은 초등교사들이 ‘집기병 속의 촛불이 꺼지는 이유’와 ‘연소 전과 후의 산소와 이산화탄소의 농도’에 대하여 과학적 개념을 형성하게 되었다. 또한 약 절반의 초등교사들이 ‘연소의 정의’와 ‘연소 후 이산화탄소의 위치‘에 대해 과학적 개념을 형성하게 되었다. 따라서 초의 연소과정에서의 기체 농도 측정 실험은 초등교사들의 연소 개념 향상에 도움을 주었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.117-119
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• 2013

Combustion stability margin of a model gas turbine has been assessed by utilizing damping ratios of measured dynamic pressure data. It is known that acoustic oscillations in combustion chambers can be described as a superposition of nonlinearly interacting oscillators. Based on this theoretical background, CSMA (Combustion Stability Margin Assessment) code has been developed. The code has been employed into a model gas turbine combustion experiment, focused on the combustion instability, to show its capability to determine the damping ratio of measured dynamic pressure and further to assess combustion stability margin of the experiment, and turned out that the code works well.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.358-365
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• 2016

In this study, one-dimensional analysis under the assumption of an inviscid flow was conducted for the experiment initiated by the French-German Research Institute of Saint-Louis (ISL) in order to investigate the energy effect of aluminum combustion. Previous theoretical analysis based on the assumptions of isentropic compression and a constant specific heat derived by ISL claimed that the experiment was not affected by the heat of aluminum combustion. However, rigorous analysis in present investigation that considered the average properties behind the shock wave compression and temperature-dependent specific heat showed that the S225 experiment was partially affected by the aluminum combustion. The increase in heat due to aluminum combustion was estimated from the rigorous analysis.

• 한국초등과학교육학회지:초등과학교육
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• 제19권2호
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• pp.15-27
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• 2000

The purpose of this study was to survey the thinking of children, preliminary elementary teachers and elementary teachers in relation to the experiment of candle's combustion in a bottle on the water, to develop some supplementary experiments for the correction of the misconception on this experiment and to propose a new teaching method for this subject-matter The results of this study can be summarized as follows. 1. Most of the answers are related to the simple observation as the extinguishing of candlelight and the water rising in the bottle after a candle's combustion. And it is appeared that all the groups are similarly short of the ability of experimental design to verify the cause and effect. 2. from the results of the developed supplementary experiments, it is concluded that the main cause of the water rising is not the combustion of oxygen, but the expansion of volume and the releasing of air in the bottle in the bottle by heat of candle's combustion. 3. Based on the above results, a new direction for the teaching method of this subject is proposed.

• 대한기계학회논문집B
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• 제28권3호
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• pp.359-364
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• 2004

For the development of high efficiency and low emission combustion systems, high temperature air combustion technology has been tested by utilizing preheated air over 1100 K and exhaust gas recirculation. In this system, combustion air is diluted with large amount of recirculated exhaust gases, such that the oxygen concentration is relatively low in the reaction zone, leading to low flame temperature. Since, the temperature fluctuations and sound emissions from the flame are small and flame luminosity is low, the combustion mode is expected to be flameless or mild combustion. Experiment was performed to investigate the turbulent flame structure and NO$_x$ emission characteristics in the high temperature air combustion focused on coflowing jet diffusion flames which has a fundamental structure of many practical combustion systems. The effect of turbulence has also been evaluated by installing perforated plate in the oxidizer inlet nozzle. LPG was used as a fuel. Results showed that even though NO$_x$ emission is sensitive to the combustion air temperature, the present high temperature air combustion system produce low NO$_x$ emission because it is operated in low oxygen concentration condition by the high exhaust gas recirculation.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.189-197
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• 2005

The usefulness of unsteady combustion was experimentally investigated using confined premixed flames stabilized by a rearward-facing step. For this purpose, apparatus of forced pulsating mixture supply, which could be modulated its amplitude and frequency, was designed. The unsteady combustion used in this experiment plays an important role in controlling self-excited combustion oscillations and furthermore it exhibits desirable performance, from a practical point of view, such as high combustion and reduction of pollutant emission like nitric oxide.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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• pp.46-52
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• 2001

In this study, the generation of oxygen-free gas using catalytic combustion for industrial applications is explained ; heat treatment and copper annealing. For the experiment, Pd catalysts were determined by testing their catalytic activities over LPG in a micro-reactor. Combustion characteristics for the generation of oxygen-free atmospheric gas and the effect of flue gas upon surface oxidation were estimated form this experiment. As a result of the experimental investigation, we can state that the catalytic combustion could generate oxygen-free atmospheric gas suitable for industrial applications, but vapor produced by combustion process must be carefully considered as a new factor of surface oxidation.

• 한국자동차공학회논문집
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• 제4권1호
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• pp.28-35
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• 1996

In this paper, we study effect of the factors, participating in the combustion as the initial conditions, such as the flow characteristics of the mixture and the initial temperature, pressure and equivalence ratio in the chamber on the ignitability of the mixture, the combustion duration and the maximum combustion-pressure. The experiment was performed in a constant-volume combustion chamber, with turbulent flow inside, equivalent to the actual engine at TDC. The present experiment utilizes three devices which differ from each other in the distribution and the magnitude of discharge energy.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.383-391
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• 2020

연구목적 : 에너지 저장실의 외부 화염에 의한 내부자기 점화 및 점화를 식별하고, 과열로 인한 점화와 외부 열원에 의한 점화의 차이를 분석하는 것이다. 연구방법 : 분리막 녹는점 측정, 배터리 외부 수열 실험, 배터리 과충전 실험, 과충전과 외부수열에 의한 연소 시 전극 판 비교분석, 과충전 연소 특징, 외부수열 화재 연소특징, 3.4(전극판 비교)/ 3.5(과충전)/ 3.6(외부수열) 분석 실험을 하였다. 연구결과: 화재 발생 시까지 센서의 위치에 따른 온도 차이가 극심했음으로 기존처럼 한 모듈 당 온도 센서 두 개로는 측정값이 부족해 온도제어를 통한 화재를 사전에 방지할 수 없다고 판단한다. 결론: 단락이 점화원으로 작용하여 혼합가스에 착화돼 가스폭발이 발생하고, 폭발 압력에 의해 전극이 잘게 파손되며, 가루형태의 리튬산화물이 불꽃반응에 의해 폭죽과 유사한 불꽃이 분출되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.325-329
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• 2017

본 연구에서는 탄화수소 계열 케로신 연료를 적용한 이중모드 램제트 연소기에 대하여 마하수 3.5~6.0 조건에서 연소시험을 수행하였다. 이릍 통해서 격리부, 상부(초음속)연소실 및 하부(아음속)연소실 내부의 온도와 압력분포를 측정하여 연소실 내부의 연소특성을 연구하였다. 마하수 3.5~5.0 까지는 아음속 연소 모드로서 하부 연소실에서 램연소를 확인할 수 있었으며, 마하수 6.0 조건에서는 인젝터에서 분사된 연료가 자연발화하여 상부 연소실에서 초음속 연소가 성공적으로 발생하였음을 확인할 수가 있었다.