• 제목/요약/키워드: temperature profiles

검색결과 991건 처리시간 0.025초

Defrost nozzle의 토출 공기에 의한 승용차 실내 유동장 및 온도장 해석 (3-D Numerical analysis of flow and temperature field of automobile cabin by discharged air from defrost nozzle)

  • 강규태;박금성;박원규;장기룡
    • 한국전산유체공학회지
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    • 제7권2호
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    • pp.25-32
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    • 2002
  • The velocity and temperature profiles in the cabin of the automobile affect greatly the comfortableness of passengers. In this paper, the three dimensional flow and temperature analysis in the cabin of real automobile have been peformed. The three dimensional Navier-Stokes equation solver was validated by comparing with the other numerical data of a 1/5 scale model. The temperature field of cavity was also analyzed for the validation of energy equation solver. After the code validation, the numerical analysis of real field of flow and temperature of an automobile was peformed and the present result provides the insight of flow and temperature field of the inside of cabin.

A STUDY OF LOW-LEVEL BOUNDARY-LAYER TEMPERATURE INVERSION EVENTS IN TAIWAN

  • Liou, Yuei-An;Yan, Shiang-Kun;Wang, Kuo-Chung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.320-323
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    • 2006
  • Temperature inversion may cause air pollution problems because air pollutants cannot be dissipated through vertical motion of the atmosphere and are accumulated near the surface. The air quality is worsen gradually if an inversion event lasts for a long time. An inversion event is defined as consecutive temperature profiles with occurrence of the temperature inversion condition. In this paper, temperature inversion events over three major cities on Taiwan are analyzed. They are measured by ground-based microwave radiometers installed in Taipei, Taichung, and Kaohsiung from 2002 to 2004 by the Environment Protection Administration (EPA) of Taiwan. Characteristics of temperature inversion events at the three cities are extracted using different classification methods.

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가열온도가 두류전분의 가용성 탄수화물의 용출양상과 전분겔 특성에 미치는 영향 (Effect of Heating Temperature on Elution Patterns of Soluble Carbohydrate of Legume Starches and the Properties of Starch Gels)

  • 권미라;안승요
    • 한국식품과학회지
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    • 제25권6호
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    • pp.698-702
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    • 1993
  • 온도 증가에 따라 용출되는 soluble carbohydrate는 온도가 증가할수록 더 큰 분자들이 많이 용출되었고 동부나 녹두는 아주 유사한 용출 양상을 보였다. 그리고 팥은 동부나 녹두보다는 분자량이 작지만 강낭콩보다는 큰 분자들이 용출되었고 $95^{\circ}C$에서의 용출양상이 동부나 녹두의 $85^{\circ}C$에서의 용출양상과 비슷해지는 것을 알 수 있었다. 그러나 강낭콩은 온도가 증가되어도 아주 작은 분자들이 계속 많이 용출되어 강낭콩 아밀로오스가 작은 분자들로 이루어져 있다는 것을 시사했다. 텍스쳐실험결과 전분겔의 특성은 녹두가 가장 견고성이 크고 동부는 응집성이 가장 컸다. 팥이나 강낭콩은 견고성과 응집성 모두 동부나 녹두에 비해 낮았다. 15분간 가열하여 제조한 전분겔의 경우 가열온도가 증가할수록 견고성과 응집성이 증가하였다. 1시간 가열하여 제조한 전분겔의 경우 동부와 녹두는 $85^{\circ}C$에서보다 $95^{\circ}C$에서 견고성이 감소하였으나 팥이나 강낭콩은 가열온도 증가에 따라 견고성이 증가하였고 시료 전분겔 모두 응집성은 증가 하는 양상을 보였다.

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사각 밀폐공간내의 자연대류의 온도 및 속도 분포에 관한 연구 (A Study on Temperature and Velocity Profiles of Natural Convection in a Square Enclosure)

  • 장태현;이종붕
    • 한국산업융합학회 논문집
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    • 제7권4호
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    • pp.391-397
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    • 2004
  • This paper presented results of experimental and numerical work for natural convection in a square enclosure by using PIV technique. 2D PIV technique and liquid crystal are employed for velocity and temperature measurement in water. The numerical method used this work is a CFD corde, STAR-CD. The experimental work are compared with these of numerical results.

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핵 폐기물 처리에 따른 지열문제(地熱問題) (Thermal Aspects of Nuclear Waste Disposal)

  • 한욱
    • 자원환경지질
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    • 제18권1호
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    • pp.49-53
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    • 1985
  • 본 연구는 핵 폐기물의 중심부에서 거리가 변화함에 따른 온도 곡선을 포함하여 폐기물 처리 계획을 이해하기 위한 수학적 모델이 적용되었다. 지열 문제를 위하여 수식의유도, 수치결과 및 제한점들을 평가하였으며 본 연구 결과와 절차로부터 방사성 물질로 인한 온도의 변화를 예측할 수 있다.

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마이크로파 레플렉토메터리를 이용한 KSIAR 플라즈마 밀도분포 재구성에 관한 연구 (Study on the Reconstruction of KSTAR Plasma Density Profiles Using Microwave Reflectometry)

  • 노영수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권8호
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    • pp.365-370
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    • 2005
  • Microwave diagnostics have been widely utilized to measure the important parameters of high temperature and high density plasmas. Reflectometry is known as a promising microwave diagnostic which has a number of merits to measure electron density profiles. In the KSTAR device, X-mode FM reflectometry is planned to measure the plasma density profiles. FM reflectometry is required to extract phase information on raw mixer IF signals, thereby obtaining time-of-flight of reflectometry signals. It is known that the data analysis method is crucial to determine the performance of FM reflectometry In fact, there are several analysis programs which have been utilized in various FM systems. Since each program was developed for a specific device, however, it is difficult to directly apply it to a different reactor like the KSTAR device. It is necessary, therefore, to develop a data analysis program for the KSTAR FM reflectometry. In this paper, complex digital demodulation (CDM) and wavelet transformation are examined in terms of the performance of density profile reconstruction. For the comparison of both methods, FM reflectometry signals are generated on the basis of assumed profiles and the interaction of the X-mode wave and the plasma. In order to see how well both methods work under various conditions, three types of profiles are assumed and noise effects are included. As a result, both methods work well under the condition of gentle density gradient and small noise level. As density gradient becomes steeper and noise level gets higher. the reconstruction performance of wavelet is better than that of CDM.

Al-Cu-Mg합금의 일방향응고시 로온도에 따른 응고거동변화 (Effects of the Furnace Temperature on the Growth Behavior of Directionally Solidified Al-Cu-Mg Alloy)

  • 문철희
    • 한국주조공학회지
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    • 제17권6호
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    • pp.545-551
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    • 1997
  • 14 cm length Al-15Cu-1Mg alloys have been directionally solidified in 3 mm diameter alumina tubes in a furnace moved with a constant velocity V=12 cm/hr under various furnace temperatures of 660, 710 and $760^{\circ}C$. By analysing the evolution of the temperature profiles along the alloy length during the solidification, the growth characteristics such as the position of the solid/liquid interface, the local growth velocity (R) and the temperature gradient at the solid/liquid interface (G) have been determined. The effects of the furnace temperature on the growth behavior have been investigated by the comparison of R and G values for each temperature. Under the furnace temperature of $760^{\circ}C$, steady state growth region was observed for the latter half of the growth period.

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InAs 양자점의 크기에 따른 분광학적 특성 (Optical properties of InAs quantum dots with different size)

  • 권영수;임재영;이철로;노삼규;유연희;최정우;김성만;이욱현;류동현
    • 한국진공학회지
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    • 제8권4A호
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    • pp.450-455
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    • 1999
  • We present Photoluminescence (PL) and Atomic Force Microscopy (AFM) image on InAs quantum dots (QDs) having different size which grown by Molecualr Beam Epitaxy (MBE). For different size QDs, analysis of the AFM profiles show that the density of QDs was the maximum value $(1.1\times10^{11}\textrm{/cm}^2)$ at 2.0 ML. In the spectra of QDs, it is found that the peak energy decreases with increasing dot size due to the effect of quantum confinement. Temperature dependence of PL intensities show that the PL is quenching and Red shift as the temperature increase. The FWHM range of 20K~180K is narrowing with increasing temperature. When temperature is over 180K, the line-width starts to in creases with increasing temperature. At last, temperature dependence of the integrated intensities were fit using the Arrehenius-type function for the activation energy. Fit value of the activation energy was increased with increasing QDs-size.

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Vertical Temperature Profile in the Yellow Sea according to the Variations of Air Temperature

  • CHO Kyu-Dae;CHO Kwang-Woo
    • 한국수산과학회지
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    • 제21권1호
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    • pp.1-10
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    • 1988
  • The vertical temperature profiles of the Yellow Sea in summer are investigated by means of the nine air temperature (AT) patterns which are classified with the AT of winter and summer. The sea surface temperature (SST) is high when the AT of summer is high, and vice versa. The gradient of thermocline in the offshore region is higher than that in the coastal region and is not always favorable with the AT patterns. The relation between sea bottom temperature (SBT) and the AT of winter is favorable when the SBT is averaged in the coastal and offshore stations. In addition, the SST of coastal stations is higher than that of offshore stations because of the strong mixing by the tidal current in the coastal region. The correlation between the AT and the SST of August is favorable (r=0.44-0.69), while the correlation between the AT of February and the SBT of August is not favorable except the stations, A2 (r=0.57) and B2 (r=0.61).

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다공질 물질의 냉각현상 연구를 통한 코크스냉각공정의 모델링 (Modeling for a Coke Dry Quenching Process Using a Theory of a Porous Material)

  • 김주한;이용주;김기석
    • 한국생산제조학회지
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    • 제21권5호
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    • pp.697-701
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    • 2012
  • Numerical modeling for a coke dry quenching process was developed and evaluated. The cokes had similar characteristics to a porous material, therefore, its quenching analysis was simplified as a cooling process of porous blocks. A uniform inlet temperature and constant properties of materials in the oven were also assumed. With given operating conditions, temperature profiles in the cokes were calculated and compared to the actual values. The calculated temperature gradient was high at the upper part of the coke flow and the cooling rate decreased as cokes came down to the exit port. The exit port temperature of cokes was similar to the measured value, however, temperature-dependent material properties and operating conditions must be considered to predict the temperature precisely. The calculated results could be applied to design a coke oven to produce high quality cokes.