• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.193-200
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• 1997

Flame spread and heat release properties and incident heat flux of interior materials subject to an igniter heat flux in a compartment are investigated and compared by using computer model. A comer fire ignition source is maintained for 10 minutes at 100 kw and subsequently increased to 300kw. In executing the model, base-line material properties are selected and one is changed for each run. Also 4 different igniter heat flux conditions and examined. Results are compared for the 12 different materials tested by the ISO Room Comer Test (9705). The time for total energy release rate to reach 1MW is examined. The parameters considered include flame heat flux and thermal inertia, lateral flame spread parameter, heat of combustion and effective heat of gasfication. The model can show the importance of each property in causing fire growth on interior Hnish materials in a compartment. The effect of ignitor heat flux and material property effects were demonstrated by using dimensionless parameters a, b and Tb. Results show that for b greater than about zero, flashover time in the ISO Room-Corner test is principally proportional to ignition time and nothing more.

• 한국화재소방학회논문지
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• 제31권6호
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• pp.16-22
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• 2017

국내에서는 복잡해지고 다양해지고 있는 건축물에서의 화재위험에 대응하기 위해 성능기반 화재안전 설계가 논의되고 있지만, 건축물에서의 다양한 인자들에 의한 화재특성의 에측의 어려움으로 인하여 성능기반 화재안전 설계의 도입이 제한되고 있다. 본 연구에서는 뉴질랜드에서 제시하고 있는 화재위험도별 화재하중 값의 실대형 화재실험을 통해 성능기반 설계 도입을 위한 기준 방향 설정 및 기초 자료로 사용하고자 하였다. 실대형 화재실험은 10 MW급의 실대형 칼로리미터에서 $0.8(L){\times}2.0(H)m$의 단일 개구부를 포함하고 있는 $2.4(L){\times}3.6(W){\times}2.4(H)m$ 크기의 시험체 틀의 내부에 목재 크립을 화재하중에 따라 배치시켜, 목재 크립이 전소할 때 까지 진행하였다. 화재실험에서 열방출률의 변화는 목재 크립에 화염이 착화 된 후 외부로 출화되는 약 90초 이후부터 급격히 증가하였으며, 위험도 레벨 1에서는 최대 4743.4 kW의 열발출률이 실험시작 후 244 초에 측정되었고 위험도 레벨 2에서는 5050.9 kW의 최대 열방출률이 497 초에 측정되었다. 또한 위험도 레벨 3에서는 최대 열방출률이 4446.9 kW로 실험시작 677 초에 측정되었다.

• 한국안전학회지
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• 제23권4호
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• pp.30-35
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• 2008

The present study has been conducted to examine the effect of grid resolution on the predicted results for electric cable fire using pyrolysis model in FDS(Fire Dynamics Simulator, version 5). The grid independent test for different grid resolutions has been performed for a PE coating cable and the grid resolution is defined by the non-dimensional characteristic length of fire and mean grid size. The calculated maximum heat release rate and mean flame spread rate were almost constant for higher grid resolution of 20${\sim}$25 and the computing time for the grid resolution takes approximately 20hours to solve flame propagation with pyrolysis model. The geometrical simplification of a electric cable dose not greatly affect on the maximum heat release rate and flame spread rate and the rectangular approximation of cable shape gives acceptable result comparing with the round cable with stepwise grid.

• 동력기계공학회지
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• 제19권3호
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• pp.29-35
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• 2015

Environmental pollution is produced by consumption of fossil fuel, therefore alternative fuels is interested for development of new energy resources and reduction of exhaust emissions for air pollution prevention. Biofuels are produced from new vegetable oil and animal fat, may be used as fuel without change of engine structure in diesel engine. In this paper, the test results on specific fuel consumption, combustion characteristics of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine, especially this biodiesel was produced from biodiesel fuel at our laboratory by ourselves. This study showed that specific fuel consumption is increased slightly, on the other hand cylinder pressure, rate of pressure rise, rate of heat release and soot were decreased slightly in the case of biodiesel blends than neat diesel oil.

• 한국연소학회지
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• 제13권2호
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• pp.14-22
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• 2008

The CH* chemiluminescence of premixed flames and their dependency on fuel types has been experimentally investigated on laminar methane and propane premixed flames. The measured chemiluminescence intensities are observed linearly proportional to the fuel flow rate, which could be interpreted as the CH* chemiluminescence signal is linearly proportional to the heat release rate under fuel lean conditions. The effect of equivalence ratio could be expressed by an exponential function as ${I_{CH*}}^{\propto}\;a_1\;{\exp}(b_1{\Phi})$, where $a_1\;=\;0.00054$ and $b_1\;=\;4.60$ for methane and $a_1\;=\;0.0056$ and $b_1\;=\;5.02$ for propane. Oscillating flames showed the temporal fluctuation of chemiluminescence intensity: however, the time averaged values are virtually identical to those of quiescent flames under the same fuel flow rate and equivalence ratio conditions. This observation suggests that there is no significant flame stretch effect on chemiluminescence intensity, in average values.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.935-940
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• 2005

We generally get the Heat Release Rate by two other method. One is the calculation method from the Oxygen consumption rate and another is the calibration curve method of Temperature rising rate. In this study we compare the results of both test methods with five same specimens. From the test result we get the difference of reproducibility and checked some reasons of the difference. This paper includes some points to be careful for more creditable results for each test method.

• 오토저널
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• 제7권3호
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• pp.74-82
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• 1985

Using single-zone heat release model and quasi-steady model, computer program for calculating the compression ignition engine cycle was composed. The properties in the cylinder were calculated in terms of crank angle and the effects of various operating conditions on rate of heat release and on engine performance were studied. The predicted values for the engine under consideration have shown good agreement with published data.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1433-1438
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• 2009

본 논문의 목적은 점화시기의 변화가 LPG/가솔린 겸용차량에 미치는 영향을 살펴보기 위한 것으로 가솔린 전용연료 모드를 LPG 전용연료 모드로 진각시킨 제어시스템을 제안하여 엔진회전수(1500rpm, 2000rpm) 및 점화시기 ($5^{\circ}$,$10^{\circ}$,$15^{\circ}$,$20^{\circ}$)의 변화에 따른 실린더내의 가스압력, 압력상승률 및 열발생률을 측정하였다. 그 결과 실런더내의 가스압력 및 압력상승률은 기관의 회전속도가 1500rpm 및 2000rpm 모두 점화시기가 진각될수록 증가하였으나, $20^{\circ}$부근에서의 압력상승률값만 약간 낮게 나타났다. 또한, 열발생률은 1500rpm에서 점화시기가 진각될수록 증가하였으며 2000rpm의 $20^{\circ}$부근에서 감소하는 경향을 볼 수 있었다.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1572-1582
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• 2003

Hybrid rocket combustion has a manifestation of stable response to the perturbations compared to solid propellant combustion. Recently, it has revealed that the low frequency combustion instability about 10 Hz was occurred mainly due to thermal inertia of solid fuel. In this paper, the combustion response function was theoretically derived by use of ZN (Zeldovich-Novozhilov) method. The result with HTPB/LOX combination showed a quite good agreement in response function with previous works and could predict the low frequency oscillations with a peak around 10 Hz which was observed experimentally. Also, it was found that the amplification region in the frequency domain is independent of the regression rate exponent n but showed the dependence of activation energy. Moreover, the response function has shown that the hybrid combustion system was stable due to negative heat release of solid fuel for vaporization, even though the addition of energetic ingredients such as AP and Al could lead to increase heat release at the fuel surface.

• 동력기계공학회지
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• 제2권2호
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• pp.20-26
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• 1998

Heat release data were obtained by analysis of cylinder diagrams from a test engine, naturally-aspirated small-size four-stroke DI diesel engine. These data were used to decide empirical coefficients of Whitehouse-Way's model, single zone combustion model. Finally, the comparison of calculated with experimental results was performed, and the accuracy of calculated versus experimental data of the model in predicting engine heat release and cylinder pressure was demonstrated.