• 제목/요약/키워드: Liquid Transient

검색결과 395건 처리시간 0.022초

마이크로 쿨러 증발기의 비등 전 과도열전달 해석 (Transient Heat Transfer Analysis on the Evaporator of a Micro-Cooler prior to Roiling)

  • 박병규;김근오
    • 대한기계학회논문집B
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    • 제26권2호
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    • pp.211-218
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    • 2002
  • It has been investigated for the temperature profile in a planar evaporator of micro-cooler subject to a uniform heat flux prior to tole initiation of boiling. The results of the analysis allow for the determination of applied power levels fur which nucleation is likely to occur only within the vapor grooves of the evaporator while maintaining subcooling in the liquid core, thereby increasing the likelihood of a successful startup. Also, limits are fecund for which additional increases in the applied heat flux do not increase the temperature difference between the vapor grooves and the wick-liquid core interface. This analysis is appropriate for the microscale evaporators of micro-cooler during a fully-flooded startup as well as starter pump designs and micro-CPLs(capillary pumped loops). The results are useful in the initial basic design of microscale heat transfer devices.

모재 분말 혼합 삽입재를 이용한 니켈기 초내열합금의 천이액상확산접합에 있어서 가열속도가 접합부에 미치는 영향 (Effects of heating rate on the bonded interlayer in base metal powder mixture used transient liquid phase diffusion bonded Ni-base superalloy)

  • 김성욱;장중철;김재철;이창희
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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    • pp.48-50
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    • 2004
  • TLP 접합 공정에서 모재와 삽입금속 사이에서의 확산을 통하여 액상 삽입금속은 고온에서 등온으로 유지 시 등온 응고된다. D.S.Duvall은 느린 가열시 매우 빠른 속도로 가열 시 보다 낮은 온도에서 dissolution이 완료되고 응고가 발생할 것으로 예상하였다. (중략)

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A Study on Bubbly flow using PIV Measurement

  • Bae, Dae-Seok
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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    • pp.50-54
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    • 2000
  • The partical-image-velocimetry with liquid crystal tracers is used for visualizing and analysis of the bubbly flow in a vertical temperature gradient. This method allows simultaneous measurement of velocity and temperature flow fields at a given instant of time. Quantitative data of velocity were obtained by applying the MQD technique to visualized image. The paper describes the method, and presents the transient velocity patterns of bubbly flow.

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모재분말/Ni기 삽입금속 분말의 혼합비에 따른 일방향응고 Ni기 초내열합금 GTD-111의 Wide Gap 천이액상확산접합부의 미세조직 변화 (Microstructural change of wide gap transient liquid phase bonding with directional solidified Ni base superalloy GTD-111 by the mixing ratio of the base metal powder/Ni base filler metal.)

  • 송우영;이봉근;한태교;예창호;강정윤
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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    • pp.155-157
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    • 2005
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용융 알칼리토금속 염화물에 대한 천이상태 이론의 적용 (Transient State Theory of Significant Liquid Structure Applied to Alkali Earth Chlorides)

  • 안운선;장세헌
    • 대한화학회지
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    • 제14권1호
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    • pp.109-112
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    • 1970
  • 액체구조의 천이상태 이론을 알칼리토금속 염화물에 적용시켜서 상태합을 유도하였다. 이 상태합으로부터 $SrCl_2$$BaCl_2$의 증기압, 몰부피, 엔트로피등의 열역학적 성질을 계산하여 실험치와 비교하였으며, 천이상태 이론이 용융염에도 잘 적용된다는 결론을 얻었다.

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레이저 자기공명 분광기용 광대역 CO 레이저의 개발 (Development of a Broad-Band CO laser for the Laser Magnetic Resonance Spectrometer)

  • 김용평
    • 한국광학회:학술대회논문집
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    • 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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    • pp.70-72
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    • 1989
  • The laser magnetic resonance (LMR) which makes use of paramagnetic properties of transient species is a powerful technique for the study of molecular radical ions. A liquid nitrogen cooled cw CO laser is developed for the LMR spectrometer in the mid-infrared region of the spectrum. The laser mid-infrared region of the spectrum. The laser system is designed to allow broad-band operation from 5 to 8${\mu}{\textrm}{m}$. The design details will be presented.

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Study of Molecular Reorientation in Liquid with Raman Spectroscopy. Intermolecular Interaction of Hexafluorobenzene with Benzene

  • Hwang, Hyun-Jin;Kim, Kwan;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제5권6호
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    • pp.245-248
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    • 1984
  • Raman spectroscopy was used to study the reorientational motion of hexafluorobenzene in benzene and also in neutral solvents. From the viscosity dependence of the reorientation time, intermolecular interaction in the systems was investigated. No evidence was found to support the presence of long-lived 1:1 complex of hexafluorobenzene and benzene. The unusual viscosity dependence of the reorientational motion observed in the systems was explained as due to the formation of transient complexes.

Butane 및 propane의 비정상 난류 제트 특성에 관한 연구 (A study on Behavior of Turbulent Transient Jets with Butane and Propane)

  • 이범호;송학현;조승환;홍성태;이대엽;이태우
    • 한국분무공학회지
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    • 제15권2호
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    • pp.74-82
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    • 2010
  • In order to understand the behavior of transient gaseous injection used in an LPG (Liquefied Petroleum Gas) engine, turbulent incompressible transient jets with butane and propane were measured and analyzed at pressures of 1.5 bar and 2.0 bar with injector diameters of 3 mm and 5 mm. Mie-scattering method with a tracer was used, and images were processed to investigate the behavior of butane and propane jets. Distances from the nozzle to transition region were measured as $L_e/d_{inj}$=4.35~19.4, where $L_e$ and $d_{inj}$ indicate respectively a distance from nozzle to transition point and nozzle diameter. Slits and tubes around jet at near-field were introduced to measure the effect of entrainment and the diameter of jet, which revealed that the entrainment of surrounding air is significant for developing jet diameter. When the entrainment is restricted, the behavior of jet became deviating from the baseline. It was found that the virtual origin located outside of a nozzle towards jet tip within the conditions of this work, and its location was estimated as $x_o/d_{inj}$=0.56~7.25, where $x_o$ is a distance from nozzle to virtual origin.

원형 및 환상 채널에 흐르는 수직 상향류의 액막 건조 모델 (Phenomenological Liquid Film Dryout Model for Upward Flow in Tubes and Annuli)

  • 홍성덕;천세영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집D
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    • pp.201-207
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    • 2001
  • We modeled the liquid film dryout(LFD) process for both tube and annulus which have uniformly heated vertical channels. We set phenomenological initial conditions in the model. The initial void fraction on the onset of the annular flow location is derived from the physical chum-to-annular flow criterion with the help of the drift-flux-model. The initial thermodynamic-equilibrium-quality is calculated by iteration with the flow quality to find the onset of the annular-flow location. Present model tends to predict very well at the lower exit quality but under-estimates at the higher exit quality. We found that the prediction error of the present model is gradually bigger as the inlet subcooling approaches near the saturation. We obtained excellent results for both tube and annulus channels as the mean of 0.97 and root-mean-square error of 11% for the number of 3883 experimental data on tubes, and of 0.96 and of 12% for 593 on annuli. The present model extended the applicable range to the relatively low exit quality region than previous LFD models.

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