• Title/Summary/Keyword: Surface equilibrium temperature

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On response of Surface Equilibrium Temperature for Change of Surface Characteristics : An EBM Study (지표 특성 변화에 대한 평형온도의 반응 연구 : EBM 연구)

  • Seo, Ye-Won;Chu, Jung-Eun;Ha, Kyung-Ja
    • The Korean Journal of Quaternary Research
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    • v.24 no.2
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    • pp.1-11
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    • 2010
  • Energy Balance Model (EBM) was used to experiment the distribution of surface equilibrium temperature which responds to external forcing associated with the surface characteristics. Surface equilibrium temperature is calculated as sum of incoming solar radiation and latitudinal transport is balanced with outgoing infrared radiation. To treat incoming solar radiation, the source of the earth energy, significantly for energy balance, the experiment for surface equilibrium temperature distribution was performed considering the energy balance with the latitudinal albedo change as well as land and sea distribution. In addition, linear albedo change experiment, arctic albedo 5%, 10%, 15% change experiments and the opposite albedo change experiments between arctic and mid-latitudes were performed using incoming solar radiation as an external forcing. Moreover, with and without ice-albedo feedback experiments were performed. Increasing of arctic albedo is blocked out the incoming solar radiation so that it induces decreasing of latitudinal heat transport. It is strengthened energy transport from low latitudes by keeping arctic low energy states. Therefore the temperature change in the mid-latitudes exhibits larger response than that of arctic due to the difference of transport. The land which has lower heat capacity than sea can be reach to equilibrium temperature shortly. Also land is more sensitive to temperature change with respects to albedo. Thus it induces the thermal difference between land and sea. As a result, the equilibrium temperature exhibits differently as the difference of albedo and heat capacity which are the one of surface characteristics. Surface equilibrium temperature decreases as albedo increase and the ratio of temperature change is large as heat capacity is small. The decreasing of surface equilibrium temperature with respects to increasing of linear albedo is accelerated by ice-albedo feedback. However local change of surface equilibrium temperature decreases non-linearly.

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Hypersonic Viscous Interaction of Wedge Flows (극초음속 쐐기 유동의 Viscous Interaction)

  • Kim K. H.;Rho O. H.
    • 한국전산유체공학회:학술대회논문집
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    • 1996.05a
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    • pp.40-45
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    • 1996
  • This paper discribes the viscous interaction of Hypersonic Wedge Flows using Roe FDS and AUSM+. For this purpose we developed the frozen and the equilibrium code and numerically simulated the viscous interaction by changing the surface temperature and the mach number. We used curve fitting data in NASA Reference Publication 1181, 1260 to calculate equilibrium properties. We compare the equilibrium flow with the frozen flow. We conclude that the mach number and the surface temperature are significant parameters, as the surface temperature and the mach number increase the viscous interaction becomes stronger, and we must consider high-temperature effects in hypersonic flow

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Surface Cleaning of Polyethylene Terephthalate Film with Non-equilibrium Atmospheric Discharge Plasma

  • Sung, Youl-Moon
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.2
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    • pp.79-83
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    • 2008
  • The dampness by treating the surface with polyethylene terephthalate (PET) film was measured to grasp the plasma parameters and was observed the surface condition with an atomic force microscope (AFM) to find the causes of the dampness. Also, the vibrational and rotational temperatures in the plasma were calculated after identifying the radicals within the plasma by analyzing the emission spectral with an emission spectrum. The hydrophilic properties were enhanced, by treating the surface of the PET film with non-equilibrium atmospheric discharge plasma. When the rotational temperature was 0.22 to 0.31 eV within the plasma, surface modification control could be easily carried out to surface treatment of PET film on non-equilibrium atmospheric pressure plasma.

The Variation of Radiative Equilibrium Temperatures with the Ice Crystal Habits and Sizes in Cirrus Clouds (권운 내 빙정의 종류와 크기에 따른 복사 평형 온도 변화)

  • Jee, Joon-Bum;Lee, Won-Hak;Lee, Kyu-Tae
    • Atmosphere
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    • v.20 no.4
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    • pp.427-436
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    • 2010
  • The single-scattering optical properties of ice crystals in cirrus clouds by the aircraft measurement data were investigated, and the radiative equilibrium temperatures and radiative fluxes were calculated and analyzed by radiative convective model with the variations of ice crystal habits and sizes in cirrus clouds. The homogeneous cloud is assumed to be in the layer 200~260 hPa with an ice crystal content of $10gm^{-2}$ for the flux calculation. The profiles of temperature, humidity, and ozone typical of mid-latitude summer are used. The surface albedo is assumed to be 0.2 for all spectral bands and the cosine of solar zenith angles is 0.5. The result of radiative equilibrium temperature at surface was less than surface temperature of the standard atmosphere data in case of smaller effective ice crystal size and larger optical thickness. The column, aggregation and plate in 6 ice crystal habits were the most effective in positive greenhouse effect and bullet-4 was the worst in it. At the surface, the maximum difference of equilibrium temperature by 6 kinds of ice crystal habits were about 3~15 K with 30 sample aircraft measurement data.

Radiative Properties of King Sejong Station in West Antarctica with the Radiative Transfer Model: Climate Change using Radiative Convective Equilibrium Model (대기 복사 모형에 의한 세종기지에서의 복사학적 특징: 복사 대류 평형 모형을 이용한 기후 변화 연구)

  • Lee, Gyu-Tae;Lee, Bang-Yong;Jee, Joon-Bum;Yoon, Young-Jun;Lee, Won-Hak
    • Journal of the Korean Geophysical Society
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    • v.9 no.1
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    • pp.27-36
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    • 2006
  • The radiative convective equilibrium (RCE) temperature was calculated for the climate change study at King Sejong Station in West Antarctica. As a result of RCE model sensitivity test, the increases of surface albedo, solar zenith angle, and cloud optical thickness decrease surface temperature. On the other hand, the increases of carbon dioxide and cirrus cloud amount are caused by surface warming due to the greenhouse effect. According to the model calculation result, annual mean surface temperature shows a upward trend of 0.012oC/year during the period of 1958-2001. During the period of 1989∼2001, the trend of monthly mean surface temperature by model calculation is 0.01oC/month and the observation trend is 0.005oC/month.

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NUMERICAL SIMULATION OF THERMOCHEMICAL NON-EQUILIBRIUM FLOW AROUND BLUNT BODIES CONSIDERING CATALYTIC WALL EFFECTS (촉매벽 효과를 고려한 무딘 물체 주위의 열화학적 비평형 유동에 대한 수치적 연구)

  • Kim, J.W.;Kwon, O.J.
    • Journal of computational fluids engineering
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    • v.18 no.3
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    • pp.87-93
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    • 2013
  • A computational study has been performed to examine the effects of catalytic walls on the stagnation region heat transfer. The boundary conditions for none, finite, and fully catalytic walls have been incorporated into a multi-block compressible Navier-Stokes solver. In the present study, both chemical and thermal non-equilibrium effects were included. The flows over a blunt body model were simulated by varying surface catalytic recombination rates. A full range of catalycities was explored in the context of a constant wall temperature assumption. Detailed information on species concentrations, temperature, and surface heat flux are presented. Comparison with available flight data of surface heat flux is also made.

Characteristics for Nanofluid Droplet Evaporation on Heated Surface at Boiling Temperature of Base Liquid (비등점의 가열 표면에서 나노유체 액적의 증발 특성)

  • Kim, Dae Yun;Jung, Jung-Yeul;Lee, Seong Hyuk
    • Journal of ILASS-Korea
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    • v.20 no.4
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    • pp.236-240
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    • 2015
  • This study aims to experimentally investigate the evaporation characteristics of nanofluid droplet on heated surface at boiling temperature of DI-water. In particular, textured surface was used to examine the effect of wettability on evaporation. At the initial stage of evaporation process, dynamic contact angle (DCA) of nanofluid droplet with 0.01 vol.% concentration on textured surface rapidly increased over its equilibrium contact angle by generated large bubble inside the droplet due to lower wettability. However, contact angle of nanofluid droplet with higher concentration on textured surface decreased with surface tension. In addition, total evaporation time of droplet on textured surface was considerably delayed due to reduction of contact area between droplet and solid surface. Thus, evaporation characteristics were highly affected by the nanofluid concentration and surface wettability.

A Comparative Study on Heat Transfer Characteristics in Tissue Model with Application of Heating or Cooling Therapeutic Modalities (조직모델에서 냉.온치료기의 열전달 특성 비교 연구)

  • Kim, Yu Jong;Shin, Kyung Min;Kim, Eun Jung;Kim, Kyung Ho;Kim, Kap Sung;Lee, Seung Deok
    • Journal of Acupuncture Research
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    • v.30 no.4
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    • pp.125-138
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    • 2013
  • Objectives : This study aimed to investigate temperature characteristics by heat transfer type of therapeutic modalities. Methods : We selected heating and cooling modalities that are frequently used in clinical by heat transfer type: conduction, convection, radiation, and conversion. We used ham as tissue model, and applied the modalities for 30 minutes. We measured real-time changed temperature($^{\circ}C$) of the surface, 2, 4, 6, 8, 10, 12, and 14 mm depth. Results : 1. In conduction-using hot pack, ice pack, and CryoStamp heating-cooling combination therapy unit($40^{\circ}C/{\sim}15^{\circ}C$), the surface temperature sharply rose close to equilibrium in first 5 minutes. 2. In convection-using smokeless moxa, temperature slowly rose to the maximum at 25-minute elapsed time. But in another convection-using CRAiS cryotherapy device, result was similar to that of conduction. 3. In radiation-using infrared lamp, result was similar to that of conduction, but not reached equilibrium during applying time. 4. In conversion-using ultrasound device, temperature was the highest at 6 mm depth, and not reached equilibrium during applying time. Conclusions : We could comprehend temperature characteristics and proper use of modalities by heat transfer type. It would be necessary to consider in vivo physical conditions in further studies.

Equilibrium Thermodynamics of Chemical Reaction Coupled with Other Interfacial Reactions Such as Charge Transfer by Electron, Colligative Dissolution and Fine Dispersion: A Focus on Distinction between Chemical and Electrochemical Equilibria

  • Pyun, Su-Il;Lee, Sung-Jai;Kim, Ju-Sik
    • Journal of the Korean Electrochemical Society
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    • v.11 no.4
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    • pp.227-241
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    • 2008
  • This article involves a unified treatment of equilibrium thermodynamics of the chemical reaction coupled with other interfacial (phase boundary) reactions. The modified (restrictive) chemical potential ${\mu}_k^+$, such as electrochemical potential, hydrostatic-chemical (mechanochemical) potential (exceptionally in the presence of the pressure difference) and surface-chemical potential, was first introduced under the isothermal and isobaric conditions. This article then enlightened the equilibrium conditions in case where the release of chemical energy is counterbalanced by the supply of electrical energy, by the supply of hydrostatic work (exceptionally in the presence of ${\Delta}p$), and finally by the release of surface energy, respectively, at constant temperature T and pressure p in terms of the modified chemical potential ${\mu}_k^+$. Finally, this paper focussed on the difference between chemical and electrochemical equilibria based upon the fundamentals of the isothermal and isobaric equilibrium conditions described above.

Analyzing the Relationship between Climate Change and Anchovy Catch using a Cointegration Test (공적분 검정을 이용한 기후변화의 멸치 생산량에 대한 영향 분석)

  • EOM, Ki-Hyuk;KIM, Hong-Sik;HAN, In-Seong;KIM, Do-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1745-1754
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    • 2015
  • This study aimed to analyze the relationship between sea temperatures and anchovy catch of Anchovy drag net fishery using annual time series data from 1970 to 2013. In the analysis, time series data on variables (CPUE, sea surface temperature, and 10m temperature) were estimated to be non-stationary from unit root tests, but one long-term equilibrium relation among variables was found from a cointegration test. From an exclusion test, a 10m temperature would not have relations with CPUE and sea surface temperature. The result of regression analysis on sea surface temperature and anchovy catch indicated that the sea surface temperature would have positive impacts on the anchovy catch. It means that when the sea surface temperature would increase, all other things including the current level of fishing effort being equal, the catch of anchovy was predicted to increase. More specifically, the result showed that when 1% of sea surface temperature increases, CPUE would be increased by 2.81%.