• Title/Summary/Keyword: Instantaneous temperature

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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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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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A Study on the Temperature Behavior on Impinging Plate of Diesel Spray with Ultra High Pressure (극초고압 디젤분무의 충돌면 온도거동에 관한 연구)

  • Lee Jong Tai;Jeong Dae Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.3 s.234
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    • pp.402-408
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    • 2005
  • The instantaneous temperature behaviors on impinging plate in case of ultra high pressure have been measured and analyzed by using the instantaneous temperature probe and ultra high pressure injection equipment. The temperature drop was largest at P1 which is center of impinging spray and decreased with propagation of spray to the radius direction. The temperature drop was bigger in case of higher temperature of impinging plate. The temperature drop decreased with increase of injection pressure. But decreasing rate of temperature drop was slight over 2,500 bars. Therefore, it was predicted that the fuel evaporation versus the increase of injection pressure was maximum at around 2,500 bars.

Characteristics of Heat Flux in Intake and Exhaust Valve of Methanol Fueled Engine (메탄올기관과 흡.배기 밸브에서의 열유속 특성)

  • 김문헌;임연기;이종태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.208-217
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    • 1996
  • Instantaneous surface temperature and unsteady heat flux of intake and exhaust valve in methanol fueled engine were investigate as a function of compression ratio and engine speed. To accomplish this purpose, the instantaneous temperature sensor was designed and it was installed into three point of intake and exhaust valve head to measure unsteady temperature. The unsteady heat flux at valves was evaluated using one dimensional heat conduction equation with the valve head temperature and temperature gradient. And also mean heat flux of intake and exhaust valve for each stroke were evaluated as a function of engine speed.

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A Effect Saving Temperature of Instantaneous Heater Using An Economical Bidet Due to Change Silicon-Tube (실리콘 튜브의 변경으로 인한 절전형 비데용 순간 히터 온도 절감 효과)

  • Chung, In-Ryong;Kim, Won-Jong;Nam, Sang-Younk;Lee, Sung-Chun
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2057-2058
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    • 2011
  • We have studied that a effect saving temperature of instantaneous heater using an economical bidet due to change Silicon-Tube. The results, we have found that the existing instantaneous heater is reduced 15 [%], 20 [%] better than a new product instantaneous heater as a discharge water [${\ell}$/min] with temperature and ${\nabla}$ value, respectively. Therefore, we have showed that the innovative effect of a working process and the cost reduction because an economical bidet due to change Silicon-Tube.

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Experimental study on the heat flux and heat transfer coefficient in a spark ignition engine (스파크 점화기관의 열유속 및 열전달 계수에 대한 실험적 연구)

  • 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.1466-1474
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    • 1997
  • In order to design and develop a spark ignition engine, many studies must be preceded about the characteristics of thermal flow. For measurement of transient wall temperature thin film thermocouples of Bendersky type were manufactured and these probes were fixed into the wall of combustion chamber. Surface wall temperatures were measured in experiments of various engine speeds. Transient heat fluxes were calculated from the wall temperature measurements. Pressure was measured from combustion chamber using pressure transducer and gas temperatures were calculated using the state equation of ideal gas. And instantaneous heat transfer coefficients were obtained. It will be the basic data for the formulae of instantaneous heat transfer coefficients.

A Study on Unsteady Thermal Loading of Hydrogen Engine with Dual Injection (이중분사식 수소기관의 비정상 열부하 해석에 관한 연구)

  • Wei, Shin-Whan;Kim, Yun-Young;Kim, Hong-Jun;Lee, Jong-Tai
    • Transactions of the Korean hydrogen and new energy society
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    • v.12 no.2
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    • pp.147-155
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    • 2001
  • To measure of thermal loading in the combustion chamber of hydrogen engine with dual injection, instantaneous wall-surface temperature and unsteady heat flux of the cylinder head are measured and analyzed. The maximum wall surface temperature is shown in direct injection region which has large heat supplied. Partial and spatial temperatures have slight deviation in transient region of injection, though injection method change suddenly. All of thermal characteristics such as instantaneous temperature, temperature swing and heat flux of hydrogen engine with dual injection are remarkably higher than those of gasoline engine. It means necessity of additional countermeasure of thermal loading.

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Experimental study on the transfer in pulse tube (맥동관 내부의 열전달에 관한 실험적 연구)

  • 김민규;남관우;정상권;장호일;정은수
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.1
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    • pp.45-50
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    • 2000
  • The present study has been conducted to observe the heat transfer under pulsating pressure and oscillating flow. The experimental apparatus was fabricated to measure the gas temperature, the wall temperature. the pressure and the instantaneous heat flux inside the pulse tube. The measured gas temperature and heat flux must be calibarated to compensate their finite time constant in the oscillating flow conditious. The experiment was performed from 1 Hz to 5 Hz. The phase difference between the instantaneous heat flux and the gas-wall temperature difference was clearly observed. The experimental heat fluxes were compared to the theroretical correlations such as Complex Nusselt Number Model(CNNM) and Variable Coefficient Model(CVM). The heat flux predisted by CNNM was always greater than that of VCM. The experiment confirmed the valisity of the VCM for the instantaneous heat flux under the pulsating pressure and oscillating flow in the warm end of the pulse tube.

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The Development of Instantaneous Heat Flux Measurement Probe and Calculation of Thermal Stress of Piston by Finite Element Method (순간 열플럭스 측정용 프루브 개발 및 유한요소법에 의한 피스톤 열응력 계산)

  • Lee, J.S.;Woo, J.H.;Lee, E.L.;Jung, I.G.;Lee, H.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.267-275
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    • 1998
  • In this study, the instantaneous heat flux measurement probe and the linkage system for the measurement of the instantaneous temperature and heat flux of the DI mono cylinder diesel engine were developed, and these were proved to have a good reliability and sensibility. A 3-D FEM model which consist of full piston to accommodate the eccentric bowl in the piston head, was applied for the analysis of the thermal stress and the temperature distribution. The mean heat flux on the piston head was used as boundary condition for the analysis of piston. The analysis showed that thermal stress concentrate on the bowl and inner surface of pin hall.

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A Study on the Ignition Characteristics of Gasoline due to Variation in Octane Number (옥탄가 변화에 따른 가솔린의 발화특성에 관한 연구)

  • Kim, Hyeong Seok;Kim, Won Kil;Choi, Yu Jung;Kim, Jung-Hun;Choi, Jae-Wook
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.45-51
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    • 2018
  • This study was conducted to assess the hazards of gasoline in relevance to the changes in octane numbers, and gasoline's spontaneous ignition temperature and instantaneous ignition temperature were measured. Spontaneous ignition temperature of regular gasoline was $301^{\circ}C$ for sample quantity of $100{\sim}125{\mu}{\ell}$. Spontaneous ignition temperature of middle gasoline was $380^{\circ}C$ for sample quantity of $125{\mu}{\ell}$ and that of premium gasoline was $400^{\circ}C$. As gasoline's octane numbers increased, their spontaneous ignition temperatures increased, and their instantaneous ignition temperature were almost identically $499^{\circ}C$ for sample quantity of $125{\mu}{\ell}$. In addition, activation energies of regular gasoline, middle gasoline, and premium gasoline were 10.48 Kcal/mol, 16.89 Kcal/mol, and 24.55 Kcal/mol respectively.