• Title/Summary/Keyword: 순간온도

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Flow Properties of Gelatinized Cowpea Flour Dispersion (동부 앙금 호화액의 흐름 성질)

  • 이애랑;김성곤;이신영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.2
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    • pp.181-185
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    • 1993
  • The effects of concentrations (6~9%), heating temperatures (80, 85, 90 and 95$^{\circ}C$) and heating methods (continuous, method A and instantaneous, method B) on the flow properties of cowpea flour (air-dried sediment) at 6$0^{\circ}C$ were studied. The gelatinized cowpea flour dispersions by method B had higher values of yield stress and consistency index but lower value of flow behavior index compared to those values of method A. The log values of consistency index were positively correlated with the concentration and heating temperature for both methods. The rate of increase in the consistency index value by method B at the same concentration was greater in all heating temperatures than that by method A.

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Determination of empirical formula for instantaneous heat transfer coefficients in a S. I. engine (스파크 점화기관의 순간열전달계수의 경험식 결정)

  • Han, Seong-Bin;Gwon, Yeong-Jik;Lee, Jeong-Yeol
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.11
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    • pp.1475-1484
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    • 1997
  • A new empirical formula for instantaneous heat transfer coefficients was determined. The determination of this formula is in need for prediction of instantaneous value of heat transfer coefficients to analyze in more detail the time variation of heat transfer rate from gas to wall in combustion chamber of a spark ignition engine. As the result, following formula was determined. h=687 $p^{0.75}$ $U^{0.75}$ $D^{0.25}$ - $T^{-0.465}$ U(.theta.)=O.494 $V_{p}$ +0.73*10$^{6}$ (1.35 p dV/d.theta.+V dp/d.theta.) Using this empirical formula, the instantaneous heat transfer coefficients of gas in the combustion chamber of spark ignition engine was predicted and compared with experimental values.

Study on the Heat Flux Using Instantaneous Temperature as Height of Probe in the Combustion Chamber (연손실 순간온도 측저에 있어서 돌출높이에 따른 실험적 연구)

  • 이치우;김지훈;김시범
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.2
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    • pp.395-402
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    • 2001
  • The gasoline engine tends to high performance, fuel economy, small-sized. Therefore, it is necessary to solve the problems on thermal load, abnormal combustion, etc, in the engine, Thine film instantaneous temperature measurement probe was made. And the manufactural method of probe was established. The instantaneous surface temperatures in the constant volume combustion chamber were measured by this probe and the heat flux was obtained by Fourier analysis. The authors measured the wall temperature of combustion chamber and computed the heat flux through the cylinder wall in order to understand the combustion characteristics depending on height of probe. For achieving this goal, the thin film instantaneous temperature probe was developed for analyzing the instantaneous surface wall temperature and unsteady heat flux on the constant volume combustion chamber.

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Study on the Heat Flux Using Instantaneous Temperature in the Constant Volume Combustion Chamber (정적연소기에서 순간온도를 이용한 열유속에 관한 연구)

  • 이치우;김지훈;하종률;김시범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.103-111
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    • 2001
  • In the present study, the internal combustion engine tends to high performance, fuel economy, small-sized. Therefore, it is necessary to solve the problems on thermal load, abnormal combustion, etc in the engine. Thin film instantaneous temperature probe was made, and the measuring system was established. The instantaneous surface temperatures in the constant volume combustion chamber were measured with this system and the heat flux was obtained by Fourier analysis. Maximum instantaneous temperatures were obtained after 55∼60ms from ignition and they increased as equivalence ratio and varied differently as the position of probe. Total heat loss during combustion time was affected by the equivalence ratio and differed widely as the position of probe.

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Measurement and Analysis of Instantaneous Surface Temperature and Unsteady Heat Flux at Combustion Chamber of DOHC Gasoline Engine ; Cylinder Linder (DOHC 가솔린기관의 연소실 벽표면순간온도 및 비정상 열유속 측정 및 해석(제3보 : 실린더 라이너에 관한 연구))

  • 위신환;이종태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.1-11
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    • 2000
  • Instantaneous temperature probes were manufactured by pressing method. By using these probes, the instantaneous surface temperature and unsteady heat flux in the cylinder liner of DOHC engine were measured. The main results are as follows; ⅰ) the instantaneous surface temperature of cylinder liner are affected by the contact of piston ring as well as burning gas. ⅱ) the wall temperature of the siamese portion is much higher than other parts. ⅲ) it was shown that the rising trend of heat flux by burning gas are nearly limited to the 1/2-stroke distance from the top of cylinder liner.

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An Experimental Study on the Measurement of Instantaneous Surface Temperature and Heat Flux on the Cylinder Head Surface of DI Diesel Engine (DI 디젤기관 실린더 헤드표면의 순간온도 및 열유속 측정에 관한 실험적 연구)

  • 이재순;김기태;이현구;강태경;우종헌;김수성
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.5
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    • pp.178-187
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    • 1997
  • For the experimental measurement of heat flux of DI diesel engine combustion chamber, the instantaneous temperature probes and data acquisition system were developed. By the analysis of measured temperatures at the cylinder head, the temperature at the point 3 which is located between intake and exhaust valve was higher than that of the other points. Temperatures at the point located mear the exhaust valve were higher than those of intake valve. The instantaneous and mean temperature at the cylinder head increases proportionally to the increase of the engine speed, while the temperature swing varies inversely. Temperature swings have influence on the maximum heat flux values from gas into head surface. It has been verified that these probes and data acquisition system perform well by the comparison of the trend of instantaneous temperature variation with that of measured combustion chamber pressure variation with respect to crank angle. It is presumed that these probes could be used in the measurement of other parts of combustion chamber as piston, cylinder wall etc. for the future study.

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Precision and accuracy of CARS spectrometer for instantaneous temperature measurement (순간 온도 측정을 위한 CARS 분광기의 정밀 정확도 분석)

  • 박승남;박철융;한재원;길용석;정석호
    • Korean Journal of Optics and Photonics
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    • v.7 no.4
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    • pp.348-356
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    • 1996
  • A mobile CARS spectrometer is constructed to measure the instantaneous temperature of gases, of which software include the quick fit methods and a least square fitting method to obtain temperatures from the spectra. Two quick-fit-methods give smaller variance of temperatures than the least square fitting method even though they consume much shorter time to yield temperatures. The precision and accuracy of CARS temperature is measured in the graphite tube blackbody furnace in reference to a radiation pyrometer. The accuracy of the CARS temperature is $\pm$2% from 1000K to 2400K and the precision is $\pm$35K at 1600K with the most accurate quick-fit-method. As a demonstration of the instantaneous measurement, the spectrometer is applied for measurement of the turbulent combustion at a certain condition. eograms(HS) are made using a relatively small number of synthesized 2D images. The influence of aliasing artifacts caused by insufficient or improper sampling is presented, and a new sampling theory is proposed, which is used to making holographic stereograms. Also, the optical system for extension of viewing distance and viewing zone is proposed. Results of this analysis can be applied to design normal holographic stereograms and computer based holographic stereograms.

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Heat Loss to Combustion Chamber Wall During Laminar Flame Propagation (층류화염전파중의 연소실 벽면으로의 열손실)

  • 이상준;한동호;김문헌;이종태;이성열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.7
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    • pp.1398-1407
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    • 1992
  • The prediction of heat loss during laminar flame propagation was carried out by measurement of gas pressure and visualization of flame propagation in the constant volume combustion chamber. And to validate the prediction, the instantaneous temperature at wall of combustion chamber was also measured. Consequently, it was found that heat loss was increased according to increasing of maximum flame travel distance, but rate of heat loss for heat release during laminar flame propagation was nearly constant. And heat loss depends on heat transfer area which was contacted the wall by burned gas regardless to spark plug location.

An Experimental Study on the Measurement of the Instantaneous Surface Temperature of the Piston of the DI Mono Cylinder Diesel Engine (직분식 단기통 디젤기관 피스톤의 순간온도 측정에 관한 실험적 연구)

  • 이재순;이현구;강태경;이응래;정인곤;안병태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.196-204
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    • 1998
  • For the experimental measurement of instantaneous surface temperature of the piston of the DI mono cylinder diesel engine, the instantaneous temperature proves, data acquisition system, and grass-hopper type linkage system were developed. The instantaneous temperatures on the piston bowl, crown, lands and skirt were measured and analyzed, and the following conclusions were derived ; (i) The crank angle for the maximum instantaneous temperature during one cycle varies and moves back and forth by the measuring positions and engine speeds. (ii) The engine speeds, the positions of the measuring points and the cooling water temperature had an effect on the instantaneous temperature amplitude. (iii) The instantaneous temperature suing phenomena appeared on the temperature profiles of the piston crown, top and second land of ring, but on the temperature profiles of the parts of the third land of the fing and skirt, they didn't appear, (iv) The isothermal lines in the piston were acquired through the operation of the finite elements method using the measured temperatures as the boundary conditions.

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A Development of Flash Fire Prediction Program for Combat System (전투 시스템의 순간 화재 예측 프로그램 개발)

  • Hwang, Hun-Gyu;Lee, Jang-Se;Lee, Seung-Chul;Park, Young-Ju;Lee, Hae-Pyeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.255-261
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    • 2013
  • In this paper, we developed and tested a program for prediction flash fire in a combat system. Purposes of the program are flash fire prediction of combat system for analysis vulnerability and survivability, and visualization for fire-related information. To do this, we defined critical components of the combat system which has probabilities of flash fire occurrence, and proposed Flash Fire Probability Tree which is based on Fault Tree Analysis(FTA). The program visualizes positions of critical components in combat system, positions of penetrated components, selected Flash Fire Probability Tree, temperature profile, and tables for properties of matters.