• Title/Summary/Keyword: autoignition

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The Measurement of Fire and Explosion Properties of n-Pentadecane (노말펜타데칸의 화재 및 폭발 특성치의 측정)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.28 no.4
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    • pp.53-57
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    • 2013
  • For the safe handling of n-pentadecane, the lower flash points and the upper flash point, fire point, AITs(auto-ignition temperatures) by ignition delay time were experimented. Also lower and upper explosion limits by using measured the lower and upper flash points for n-pentadecane were calculated. The lower flash points of n-pentadecane by using closed-cup tester were measured $118^{\circ}C$ and $122^{\circ}C$. The lower flash points and fire point of n-pentadecane by using open cup tester were measured $126^{\circ}C$ and $127^{\circ}C$, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-pentadecane. The experimental AIT of n-pentadecane was $195^{\circ}C$. The calculated lower and upper explosion limit by using measured lower $118^{\circ}C$ and upper flash point $174^{\circ}C$ for n-pentadecane were 0.54 Vol.% and 6.40 Vol.%.

Unsteady Three-Dimensional Analysis of Transverse Fuel Injection into a Supersonic Crossflow using Detached Eddy Simulation Part II : Reacting Flowfield (DES를 이용한 초음속 유동내 수직 연료분사 유동의 비정상 3차원 해석 Part II : 반응 유동장)

  • Won, Su-Hee;Jeung, In-Seuck;Choi, Jeong-Yeol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.9
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    • pp.879-888
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    • 2009
  • Unsteady three-dimensional reacting flowfield generated by transverse hydrogen injection into a supersonic mainstream is numerically investigated using DES and finite-rate chemistry model. Comparisons are made with experimental results to investigate the turbulent reacting flow physics. The numerical OH distribution describes well the experimental OH-PLIF result, while the numerical ignition delay time shows some disparity due to the restricted available experimental data. The intermittency phenomena are identified by the comparative analysis between RANS and DES. Those effects are also quantified by the temperature distributions along streamlines and superimposed OH mass fraction along with time.

Methods of Knock Signal Analysis in a S.I. Engine (4 기통 스파크 점화 기관의 노킹 신호 해석 방법)

  • Kim, K.W.;Chun, K.M.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.3
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    • pp.12-21
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    • 1993
  • In recent years, high efficiency, high performance, and low pollutant emmision engines have been developed. Knock phenomenon has drawn interests because it became an hinderance to engine power and efficiency increase through higher compression ratio. Knock phenomenon is an abnormal combustion originated from autoignition of unburned gas in the end-gas region during the later stage of combustion process and accompanied a high pitched metallic noise. And this phenomenon is characterized by knock occurrence percentage, knock occurrence angle and knock intensity. A four cylinder spark ignition engine is used in our experiment, and its combustion chamber pressure is measured at various engine speeds, ignition timing. The data are analyzed by numerous methods in order to select the optimum methods and to achieve better understanding of knock characteristics. Methods using band-pass filter, third derivative and step method are shown to be the most suitable, while methods using frequency analysis are shown to be unsuitable. Because step method only uses signals above threshold value during knocking condition, pressure signal analyses with this method show good signal-to-noise ratio.

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The Measurement and Investigation of Fire and Explosion Characteristics of Cyclohexanone (사이클로헥사논의 화재 및 폭발 특성치의 측정 및 고찰)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.25 no.4
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    • pp.28-34
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    • 2011
  • For the safe handling of cyclohexanone, the explosion limits at $25^{\circ}C$ were investigated. The lower flash points and AITs (auto-ignition temperatures) by ignition time delay for cyclohexanone were experimented. By using the literatures data, the lower and upper explosion limits of cyclohexanone recommended 1.1 Vol.% ($100^{\circ}C$) and 9.4 Vol.%, respectively. The lower flash points of cyclohexanone were experimented $42{\sim}43^{\circ}C$ by using closed-cup tester and $49{\sim}51^{\circ}C$ by using open cup tester. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for cyclohexanone and the experimental AIT of cyclohexanone was $415^{\circ}C$.

Appropriateness of MSDS by Means of the Measurement of Combustible Properties of Anisole (아니솔의 연소특성치의 측정에 의한 MSDS의 적정성)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.20-24
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    • 2015
  • For the safe handling of anisole, this study was investigated the explosion limits of anisole in the reference data. The flash points and auto-ignition temperatures (AITs) by ignition delay time were experimented. The lower flash points of Anisole by using closed-cup tester were experimented in $39^{\circ}C$ and $42^{\circ}C$. The lower flash points of Anisole by using open cup tester were experimented in $50^{\circ}C$ and $54^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for Anisole. The AIT of Anisole was experimented as $390^{\circ}C$. The lower explosion limit (LEL) by the measured the lower flash point for Anisole were calculated as 1.07 Vol%.

The Measurement of Combustible Properties of Cyclohexanol (사이클로헥산올의 연소특성치의 측정)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.28 no.2
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    • pp.64-68
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    • 2014
  • For the safe handling of cyclohexanol, this study was investigated the explosion limits of cyclohexanol in the reference data. The flash points and auto-ignition temperatures (AITs) by ignition delay time were experimented. The lower flash points of cyclohexanol by using closed-cup tester were experimented in$60^{\circ}C{\sim}64^{\circ}C$. The lower flash points of cyclohexanol by using open cup tester were experimented in $66^{\circ}C{\sim}68^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for cyclohexanol. The AIT of cyclohexanol was experimented as $297^{\circ}C$. The lower explosion limit (LEL) and the upper explosion limit UEL) by the measured the lower flash point and the upper flash point of cyclohexanol were calculated as 0.95 Vol% and 10.7 Vol%, respectively.

The Measurement of Fire and Explosion Properties of n-Hexadecane (노말헥사데칸의 화재 및 폭발 특성치의 측정)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.39-45
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    • 2014
  • For the safe handling of n-hexadecane, the lower flash points and the upper flash point, fire point, AITs(auto-ignition temperatures) by ignition delay time were experimented. Also lower and upper explosion limits by using measured the lower and upper flash points for n-hexadecane were calculated. The lower flash points of n-hexadecane by using the Setaflash and the Pensky-Martens closed testers were measured $128^{\circ}C$ and $126^{\circ}C$, respectively. The lower flash points of the Tag and the Cleveland open cup testers were measured $136^{\circ}C$ and $132^{\circ}C$, respectively. The fire points of the Tag and the Cleveland open cup testers were measured $144^{\circ}C$. respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-hexadecane. The experimental AIT of n-hexadecane was $200^{\circ}C$. The calculated lower and upper explosion limit by using measured lower $128^{\circ}C$ and upper flash point $180^{\circ}C$ for n-hexadecane were 0.42 Vol.% and 4.70 Vol.%.

Prediction of Minimum Spontaneous Ignition Temperature(MSIT) of the Mixture of n-Pentanol and Ethylbenzene (n-Pentanol과 Ethylbenzene 혼합물의 최소자연발화온도의 예측)

  • Ha, Dong-Myeong
    • Journal of the Korean Institute of Gas
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    • v.16 no.2
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    • pp.45-51
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    • 2012
  • The MSITs(Minimum Spontaneous Ignition Temperatures) or AITs(Autoignition Temperatures) describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. This study measured the MSITs(Minimum Spontaneous Ignition Temperatures) of n-pentanol+ethylbenzene system by using ASTM E659 apparatus. The MSITs of pure n-pentanol and ethylbenzene were $285^{\circ}C$ and $475^{\circ}C$, respectively. The experimental MSITs of n-pentanol+ethylbenzene system were a in good agreement with the MSIT calculated by the proposed equations with a few A.A.D.(average absolute deviation).

Concave surface curvature effect on heat transfer from a turbulent round impinging jet (오목표면곡률이 난류원형충돌제트의 열전달에 미치는영향)

  • Im, Gyeong-Bin;Lee, Dae-Hui
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.5
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    • pp.691-699
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    • 1997
  • The effects of concave hemispherical surface curvature on the local heat transfer from a turbulent round impinging jet were experimentally investigated. The liquid crystal transient method was used for these measurements. This method, which is a variation on the transient method, suddenly exposes a preheated wall to an impinging jet while video recording the response of liquid crystals for the measurement of the surface temperature. The Reynolds number ranges from Re=11,000 to 50,000, the nozzle-to- surface distance from L/d=2 to 10, and the surface curvature from D/d=6 to 12.The present results are also compared to those for the flat plate case. In the experiment, the local Nusselt numbers tend to increase in all regions with an increasing surface curvature. The maximum Nusselt number for all Reynolds numbers occurred at L/d .ident. 6 and a second maximum in the Nusselt number occurred at R/d .ident. 2 for both Re=23,000 and Re=50,000 in the case of L/d=2 and for Re=50,000 only in the case of L/d=4. Meanwhile, as the surface curvature increases, the value of the secondary maximum Nusselt number decreases. All the other cases exhibit monotonically decreasing values of the Nusselt number along the curved surface. The stagnation point Nusselt numbers are well correlated with Re, L/d, and D/d.

Measurement and Prediction of Combustion Properties of Styrene (스티렌의 연소특성치 측정 및 예측)

  • Ha, Dong-Myeong;Na, Byeong-Gyun
    • Journal of the Korean Institute of Gas
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    • v.17 no.4
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    • pp.70-76
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    • 2013
  • For the safe handling of styrene, this study was investigated the explosion limits of styrene in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. As a results, the lower and upper explosion limits of styrene recommended 0.9 Vol.% and 8.0 Vol.%, respectively. The lower flash points of styrene by using closed-cup tester were experimented $29^{\circ}C{\sim}31^{\circ}C$. The lower flash points of styrene by using open cup tester were experimented $32^{\circ}C{\sim}36^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for styrene. The experimental AIT of styrene was $460^{\circ}C$.