• Title/Summary/Keyword: Local temperature distribution

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Analysis of Air Temperature Change Distribution that Using GIS technique (GIS 기법을 이용한 대기온도 변화 분포 분석)

  • Jung, Gyu-Young;Kang, In-Joon;Kim, Soo-Gyum;Joo, Hong-Sik
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.395-397
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    • 2010
  • AWS that exist in Pusan is watching local meteorological phenomena established in place that the weather observatory does not exist by real time, and is used usefully to early input data of numerical weather forecasting model. I wished to display downtown of Pusan and air temperature change of peripheral area using this AWS data. Analyzed volatility using AWS observation data for 5 years to recognize air temperature change of Pusan area through data about temperature among them. Drew air temperature distribution chart by season of recapitulative Pusan area applying IDW linear interpolation with this.

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Measurement of Cross-sectional Temperature Distribution in Micro-scale Gap Fluid Using LIF Technique in Combination with CLSM (LIF 및 CLSM을 결합한 미소 간극 내 유체의 단면 온도 분포 측정 기법)

  • Jeong, Dong-Woon;Lee, Sang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.9 s.252
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    • pp.834-841
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    • 2006
  • In the present wort the Laser-induced Fluorescence (LIF) technique and Confocal Laser Scanning Microscopy (CLSM) have been combined to measure the temperature distribution across a micro-scale liquid layer as a direct and non-invasive method. Only the fluorescent light emitted from a very thin volume around a focal plane can be selectively detected, and it enables us to measure the liquid temperatures even at the close vicinity of the walls. As an experimental verification, a test section consists of two flat plates (for heating and cooling, respectively) separated by about 240 microns was made, and the methanol mixed with a temperature-sensitive dye, Rhodamine B, was filled in the gap between them. The measured temperature distribution across the gap showed good linearity, which is a typical characteristic of conduction heat transfer through a thin liquid layer. In result, the CLSM-LIF technique proposed in the present study was found to be a promising method to measure the local temperatures in the liquid flow field in microfluidic devices.

On the two phase detonation in carbon laden oxygen : taking into account of inner particle temperature distribution (입자온도 분포를 고려한 탄소입자와 산소에서의 이상폭발현상에 관한 연구)

  • 승성표;백승욱
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.1104-1112
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    • 1988
  • In this study the structure of a two phase detonation has been numerically investigated through the assumption of a steady and one-dimensional flow in the suspension of carbon particles and pure oxygen. The bow shock formation in front of carbon particles has been taken into consideration when the relative velocity of gas flow with respect to the particle exceeds the local speed of sound. But its effect was found to be very limited to the induction zone only. Furthermore the interior particle temperature distribution has been considered in this work. It was found that the inner temperature gradient was very steep in the region of high relative velocity. On the while the temperature distribution inside the particle was almost uniform in the region of low relative velocity. Overall, the effect of the interior particle temperature distribution has been significant in the two phase detonation.

Estimation of Local Surface Temperature from EBM with the Use of GRID/GIS and Remote Sensed data (GRID/GIS 및 RS 자료를 이용한 에너지 평형 모형으로부터의 국지적 지표 온도 산출)

  • 신선희;하경자;김재환;오현미;조명희
    • Korean Journal of Remote Sensing
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    • v.20 no.2
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    • pp.103-116
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    • 2004
  • The mesoscale atmospheric models to produce surface temperature can not generally consider the effect of the sloped terrain for direct solar radiation. These have not showed the regional difference of solar radiation and as a result, have made the big error in the local surface temperature. Therefore, we wished to represent the exact locality of surface temperature by considering the geometric properties of surface as well as the vegetated properties of surface. The purpose of the study is to produce local surface ground temperature in sloped terrain diagnostically using surface Energy Balance Model (EBM) with the use of GRID model in Geographic Information Systems (GIS). In this study, surface inhomogeneity over southeastern part of Korean peninsula are considered in estimation of the absorbed surface solar radiation in terms of the illumination angle, depending on topographical aspect and slope in GRID. Also, the properties of vegetated surface which the major components for the variability of surface temperature are considered in terms of NDVI. The results of our study show the locally changes in the surface ground temperature due to local ground aspect and slope effect and local properties of vegetated surface. The more detailed distribution of local surface temperature may drive the local circulation at lower atmospheric and it may explain better the real local circulation.

Empirical Correlations of Frost Thickness and Frost Surface Temperature on Heat Exchanger Fin (열교환기 휜에서의 서리층 두께와 서리층 표면온도의 실험 상관식)

  • Kim, Kyoung-Min;Kim, Jung-Soo;Kim, Jang-Hyun;Lee, Kwan-Soo
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.798-803
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    • 2009
  • In this study, dimensionless correlations of frost properties (i.e. the thickness and surface temperature of frost) on heat exchanger fin with nonuniform temperature distribution are proposed from frosting experiments. We analyzed the local fin temperature distribution, frost thickness and frost surface temperature on a 2D fin; in the airflow direction and the direction perpendicular to airflow. As a result, the frost growth on the fin had a close relation with fin heat conduction. The dimensionless correlations for the average frost properties were expressed as a function of dimensionless temperature, humidity ratio, Reynolds number, and Fourier number. These correlations agreed well with experimental data with the error less than 14%.

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An Experimental Study on the Temperature Distribution of Square CFT Columns According to the Types of Fire Protection (내화피복 종류에 따른 각형 CFT기둥의 온도분포에 관한 실험적 연구)

  • Kim, Hae-Soo;Lee, Chy-Hyoung
    • Journal of Korean Society of Steel Construction
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    • v.22 no.6
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    • pp.523-532
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    • 2010
  • Concrete-filled square steel tube (CFT) columns have inherently high fire resistance and load-bearing capacity. Nevertheless, it is sometimes necessary to improve their fire resistance using external fire protection. This paper presents the experimental results of the temperature distribution of CFT columns with fire protection. A fire load test was carried out by exposing small-scale specimens to heat in an electric furnace that was especially built for testing loaded columns. The temperature distribution of CFT columns under constant axial loads was determined, as were its significant parameters, such as the types of fire protection and thickness, the thickness of the square CFT, and the fire duration times. The results of this study showed the temperature distribution of each specimen of the electric furnace and the temperature distribution properties of concrete and steel. In addition, the axial displacement and local buckling behavior of CFT columns based on temperature changes was observed.

A Prediction Model for Condensation of Zeotropic Refrigerant Mixtures Inside a Horizontal Smooth Tube (수평평활관내의 비공비 혼합냉매의 응축에 대한 예측모델)

  • ;;小山繁
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.4
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    • pp.262-270
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    • 2001
  • This paper deals with a prediction method for the condensation of ternary refrigerant mixture inside a horizontal smooth tube. Based on some reliable assumptions, the governing equations for the local heat and mass transfer characteristics are derived, and the prediction for the condensation of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a, including R407C, is carried out. The local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, mass flux etc. are obtained for a constant wall temperature and a constant wall heat flux conditions, and the effects of the composition of HFC32/HFC125/HFC134a on heat transfer characteristics are examined. The prediction result is also compared with experimental data for condensation of ternary refrigerant mixtures. The predicted wall temperature distribution has a similar trend with experimental data but the predicted local heat transfer coefficients are 20-30% higher than the experimental data.

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Forced Convection Boiling Heat Transfer from a Horizontal Cylinder to Subcooled Water

  • Lee, Sung-Hong;Lee, Euk-Soo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.7
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    • pp.79-90
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    • 1999
  • This investigation presents the experimental results of forced convection boiling heat transfer around a circular, electrically heated horizontal cylinder to subcooled water in cross flow. In these experiments, the following primary variables were included: heat flux, flow velocity, pressure and degree of subcooling at inlet. Local surface temperatures were measured at nine peripheral positions. Local surface temperature distributions are classified into four categories depending on the supplied heat flux. The effects of the boiling curve depending on the fluid velocity, degree of subcooling at inlet and pressure are presented.

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An Experimental Study on Swirling Flow with Heat Transfer in the Horizontal Circular Annuli

  • Chang Tae-Hyun
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.3
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    • pp.260-274
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    • 2005
  • An experimental investigation was performed to study the characteristics of turbulent swirling flow in the cylindrical annuli. The swirl angle measurements were performed by flow visualization technique using smoke and dye liquid. By using the particle image velocimetry method. this study has found the time-mean velocity distribution and turbulent intensity with swirl for Re=20,000. 30.000. 50.000. and 70,000 along longitudinal sections. The results appear to be physically reasonable. Other experimental study was performed to investigate heat transfer characteristics of turbulent swirling air flow in axisymmetric annuli. The static pressure. the local air flow temperature, and the wall temperature with decaying swirl were measured by using thermocouples and the friction factor and the local Nusselt number were calculated for Re=30,000. 50,000 and 70000. The local Nusselt number was compared with that obtained from the Dittus-Boelter equation with swirl and without swirl, respectively. The results showed that the swirl enhances the heat transfer at the inlet and the outlet of the test tube.

Analysis of the Physiological Signal Measured by Oriental Medicine Instruments in the View of the Rule of Promoting and Counteracting Relation of the Five Evolutive Phases (한방기기(韓方機器)로 측정(測定)한 생리신호(生理信號)의 오행(五行) 생극제화규율적(生剋制化規律的) 해석(解析))

  • Jang, K.S.;Choi, J.W.;Jean, C.S.;Na, C.S.;So, C.H.
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.84-103
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    • 1996
  • The physiological signals measured by Oriental Medicine instruments have been analyzed quantitatively in the view of the rule of promoting and counteracting relation of five evolutive phases theory. We tried to reduce the physiological signals measured by EAV(Elec-tro-Acupuncture according to Voll) and IR thermography to the representation of five evelutive phases. The EAV index and local skin temperature on acupuncture points of each phases measured and normalized so that the total value of five phases became unity. We assumed that the normalized EAV index and local skin temperature mean the deficiency or excess of Qi for each phases. The state of Qi distribution for each phases were approximately agree with the diagnostic pattern of O. M. doctor. Taking account of the Qi distribution state of·or the five evolutive phases, we performed a proper needle insertion on acupuncture points to induce the distinct change of Qi for each phases. We compared the measured results with the predictions of Qi variation by the rule of pro- moting and counteracting relation over the five evolutive phases. For all cases, the variation of Qi in the own phase on which a needle insertion was performed were exactly same to the theoretical prediction and partial agreement was shown for the other four phases. The same analysis was carried to the results of skin temperature measurements at accupoints. We found that the local skin temperature at accupoints of each phases shelved a finite change by the needle insertion and the behavior- of its change were strongly correlated to the rule of promoting and counteracting relation of five evolutive phases.

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