• Title, Summary, Keyword: bubble-point

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Effect of Polymer Concentration and Solvent on the Phase Behavior of Poly(ethylene-co-octene) and Hydrocarbon Binary Mixture (Poly(ethylene-co-octene)과 탄화수소 2성분계 혼합물의 상거동에 대한 고분자 농도 및 용매의 영향)

  • Lee, Sang-Ho;Chung, Sung-Yun;Kim, Hyo-Jun;Park, Kyung-Gyu
    • Elastomers and Composites
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    • v.39 no.4
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    • pp.318-323
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    • 2004
  • Cloud-point and bubble-point curves for poly(ethylene-co-13.8 mol% octene) ($PEO_{13.8}$) and Poly(ethylene-co-15.3 mol% octene) ($PEO_{15.3}$) were determined up to $150^{\circ}C$ and 450 bar in hydrocarbons which have different molecular size and structure. Whereas ($PEO_{15.3}$+ n-pentane) system has cloud-point and bubble-point type transitions, ($PEO_{15.3}$+ n-propane) and ($PEO_{15.3}$+ n-butane) systems do only cloud-point type transition. In cyclo-pentane, -hexane, -heptane, and -octane, $PEO_{15.3}$ has a bubble-point transition. ($PEO_{13.8}$+ n-butane) mixture has a critical mixture concentration at 5 wt% PEO. (PEO + hydrocarbon) mixtures exhibit LCST type behavior. Solubility of PEO increases with hydrocarbon size due to increasing dispersion interaction which is favorable to dissolve PEO.

A Study on the Vertical upward Bubble Flow using Image Processing Technique (영상기법을 이용한 수직상향 기포유동에 관한 연구)

  • 서동표;오율권
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.5
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    • pp.617-623
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    • 2003
  • In the present study, the characteristics of upward bubble flow were experimentally investigated in a liquid bath. The velocity of upward bubble flow was calculated for two different experimental conditions:1) bubble flow without kinetic energy 2) bubble flow with kinetic energy. Bubble flow without kinetic energy starts to undergo the effect of buoyancy l0cm away from the nozzle. Whereas. kinetic energy is dominant before 30 cm away from the nozzle in bubble flow but after this point kinetic energy and inertial force are applied on bubble flow at the same time In addition, as the flow rate increases the maximum velocity point moves to the nozzle. The velocity Profiles near free surface is extremely irregular due to surface flow. Gas volume fraction is high near the nozzle due to gas concentration. but decreases with the increasement of axial position. Gas volume fraction does not vary after the axial position, z=60 in spite of the increasement of flow.

Parameter identification for the bubble point measurement of Liquid Acquisition Device (액체포집장치의 기포점 측정을 위한 변수식별)

  • Jeon, Sang-Eon;Park, Soo-Hyung;Byun, Yung-Hwan;Jung, Young-Suk;Oh, Seung-Hyub
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.416-423
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    • 2012
  • Liquid acquisition device in the liquid propellant supply system is required to protect entrance of gas bubble into the propulsion system. The device exploits the capillary effect of micro-sized poles in a screen and supplies pure liquid-phase propellant to the propulsion system. The bubble point is the most important performance parameter in the design of a liquid acquisition device. In this paper, performance parameters affecting the bubble point are identified through literature survey, in order to develop the experimental setup for the bubble point measurement.

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Phase Behavior Study of Poly(ethylene-co-octene) in normal-Hydrocarbons

  • Kwon, Hyuk-Sung;Lee, Sang-Ho
    • Elastomers and Composites
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    • v.38 no.1
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    • pp.51-56
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    • 2003
  • Cloud-point and bubble-point data to $170^{\circ}C$ and 50 bar are presented for four different solvents, normal pentane. n-hexane, n-heptane, and n-octane with poly(ethylene-co-42 wt% octene) ($PEO_{42}$) copolymer. The pressure-concentration isotherms measured for $PEO_{42}$ - normal pentane have maximums at around 5 wt% of the copolymer concentrations in the solution. $PEO_{42}$- normal pentane system exhibits LCST-type phase behavior at temperatures greater than $130^{\circ}C$. Below $120^{\circ}C$, bubble-point type transitions are observed. However, the binary mixtures for $PEO_{42}$ in n-hexane, n-heptane, and n-octane have only bubble-point type transitions at the pressure-temperature region investigated in this study. The single-phase region of PEO - alkane mixtures increases with the molecular size of alkane solvent due to the increasing dispersion interactions between PEO and the alkane.

Measurement and Modeling of Bubble Points for Binary Mixtures of Carbon Dioxide and N,N-Dimethylformamide (이산화탄소와 디메틸포름아마이드 혼합물의 기포점 측정 및 모델링)

  • Jung, Joon-Young;Lee, Byung-Chul
    • Clean Technology
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    • v.17 no.1
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    • pp.19-24
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    • 2011
  • The bubble point pressures of binary mixtures of carbon dioxide ($CO_2$) and N,N-dimethylformamide (DMF) were measured by using a high-pressure experimental apparatus equipped with a variable-volume view cell, at various $CO_2$ compositions in the range of temperatures above the critical temperature of $CO_2$ and below the critical temperature of DMF. The experimental bubble point pressure data were correlated with the Peng-Robinson equation of state (PR-EOS) to estimate the corresponding dew point compositions at equilibrium with the bubble point compositions. The experimentally measured bubble point pressures gave good agreement with those calculated by the PR-EOS. The variable-volume view cell equipment was verified to be an easy and quick way to measure the bubble point pressures of high-pressure compressible fluid mixtures.

Measurement of Bubble Points of Dimethyl Carbonate and Carbon Dioxide Mixtures (디메틸카보네이트와 이산화탄소 혼합물의 기포점 측정)

  • Ahn, Joon-Yong;Lee, Byung-Chul
    • Applied Chemistry for Engineering
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    • v.20 no.1
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    • pp.94-98
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    • 2009
  • The bubble point pressures of dimethyl carbonate and carbon dioxide mixtures were measured by using a high-pressure experimental apparatus equipped with a variable-volume view cell, at various $CO_2$ compositions in the range of temperatures above the critical temperature of $CO_2$ and below the critical temperature of dimethyl carbonate. The experimental bubble point pressure data were correlated with the Peng-Robinson equation of state (PR-EOS) to estimate the corresponding dew point compositions at equilibrium with the bubble point compositions. The experimentally measured bubble point pressures gave good agreement with those calculated by the PR-EOS. The variable-volume view cell equipment was verified to be an easy and quick way to measure the bubble point pressures of high-pressure compressible fluid mixtures.

MULTI-HARMONIC MODELS FOR BUBBLE EVOLUTION IN THE RAYLEIGH-TAYLOR INSTABILITY

  • Choi, Sujin;Sohn, Sung-Ik
    • Journal of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.663-673
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    • 2017
  • We consider the multi-harmonic model for the bubble evolution in the Rayleigh-Taylor instability in two and three dimensions. We extend the multi-harmonic model in two dimensions to a high-order and present a new class of steady-state solutions of the bubble motion. The growth rate of the bubble is expressed by a continuous family of two free parameters. The critical point in the family of solutions is identified as a saddle point and is chosen as the physically significant solution. We also present the multi-harmonic model in the cylindrical geometry and find the steady-state solution of the axisymmetric bubble. Validity and limitation of the model are also discussed.

Sonoluminescence Characteristics from Submicron Size bubbles (마이크로 이하 기포로부터의 소노루미네센스 특성)

  • Byun, Ki-Taek;Karng, Sarng-Woo;Kim, Ki-Young;kwak, Ho-Young
    • Proceedings of the KSME Conference
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    • pp.1201-1206
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    • 2004
  • Sonoluminescence (SL) characteristics such as pulse shape, radiance and spectrum radiance from submicron bubbles were investigated. In this study, a set of analytical solutions of the Navier-Stokes equations for the gas inside bubble and equations obtained from mass, momentum and energy equations for the liquid layer adjacent the bubble wall were used to estimate the gas temperature and pressure at the collapse point, which are crucial parameters to determine the SL characteristics. Heat transfer inside the gas bubble as well as at the liquid boundary layer, which was not considered in the most of previous studies on the sonoluminescence was taken it into account in the calculation of the temperature distribution inside the bubble. It was found that bremsstrahlung is a very possible mechanism of the light emission from either micron or submicron bubbles. It was also found that the peak temperature exceeding $10^{6}$ K in the submicron bubble driven at 1 MHz and 4 atm may be due to the rapid change of the bubble wall acceleration near the collapse point rather than shock formation.

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New Bubble Size Distribution Model for Cryogenic High-speed Cavitating Flow

  • Ito, Yutaka;Tomitaka, Kazuhiro;Nagasaki, Takao
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.700-710
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    • 2008
  • A Bubble size distribution model has been developed for the numerical simulation of cryogenic high-speed cavitating flow of the turbo-pumps in the liquid fuel rocket engine. The new model is based on the previous one proposed by the authors, in which the bubble number density was solved as a function of bubble size at each grid point of the calculation domain by means of Eulerian framework with respect to the bubble size coordinate. In the previous model, the growth/decay of bubbles due to pressure difference between bubble and liquid was solved exactly based on Rayleigh-Plesset equation. However, the unsteady heat transfer between liquid and bubble, which controls the evaporation/condensation rate, was approximated by a theoretical solution of unsteady heat conduction under a constant temperature difference. In the present study, the unsteady temperature field in the liquid around a bubble is also solved exactly in order to establish an accurate and efficient numerical simulation code for cavitating flows. The growth/decay of a single bubble and growth of bubbles with nucleation were successfully simulated by the proposed model.

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A Study on the Bubble Flow in the Gas-Liquid Plume (기-액 기둥에서 기포유동에 관한 연구)

  • Seo, Dong-Pyo;Hong, Myung-Seok;Oh, Yool-Kwon
    • Proceedings of the KSME Conference
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    • pp.2105-2108
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    • 2003
  • The characteristics of upward bubble flow were experimentally investigated in a liquid bath. In the present study, a thermal-infrared camera and high speed CCO camera were used to measure their temperature and local rising velocity, respectively. Heat transfer from bubble surface to water is largely completed within z=10mm from the nozzle, and then the temperature of bubble surface reaches that of water rapidly. The rising velocity of bubble was calculated for two different experimental conditions: 1) bubble flow without kinetic energy 2) with kinetic energy. Bubble flow without kinetic energy starts to undergo the effect of inertia force 10cm away from the nozzle. Whereas, kinetic energy is dominant before 30 cm away from the nozzle in bubble flow, but after this point, kinetic energy and inertial force are applied on bubble flow at the same time.

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