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  • 1
    Electronic Resource
    Electronic Resource
    Cubic equations of state for transport properties: An equation for the thermal conductivity of oxygen (1990)
    Springer
    International journal of thermophysics 11 (1990), S. 1011-1023 
    Details
    ISSN: 1572-9567
    Keywords: equation of state (cubic) ; oxygen ; thermal conductivity ; transport equation of state
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A scheme for the development of equations for the transport properties in terms of pressure and temperature, so-called transport equations of state, is presented. The surfaces of transport properties and density as a function of pressure and temperature reveal similarities, which become even more evident when the residual transport property as a function of pressure and temperature is considered. Even the spinodals of transport and thermal properties coincide in the p, T plane, as can be shown mathematically and as was already empirically found for water and oxygen. Based on these similarities a cubic transport equation of state is evaluated for the residual thermal conductivity of oxygen. The new equation is only a little less accurate than the already established virial transport equation of state for oxygen. It is, however, much simpler and needs only a few parameters. The accuracy is still good enough for practical applications. The results demonstrate that cubic equations of state can describe transport properties and are a basis for generalized estimation methods for the transport properties of fluids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500556
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  • 2
    Electronic Resource
    Electronic Resource
    Transport properties of 1,1,1,2-tetrafluoroethane (R134a) (1993)
    Springer
    International journal of thermophysics 14 (1993), S. 951-988 
    Details
    ISSN: 1572-9567
    Keywords: 1,1,1,2-tetrafluoroethane ; correlation ; critical region ; equation of state ; HFC-134a ; R134a ; thermal conductivity ; transport properties ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New equations for the thermal conductivity and the viscosity of R134a that are valid in a wide range of pressures and temperatures are presented. They were obtained through a theoretically based, critical evaluation of the available experimental data, which showed considerable inconsistencies between data sets, in particular in the vapor phase. In the critical region the observed enhancement in the thermal conductivity is well represented by a crossover model for the transport properties of fluids. Since thermodynamic properties enter into the calculation of the critical enhancement of the transport properties, a new fundamental equation for the critical region was developed also.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502117
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  • 3
    Electronic Resource
    Electronic Resource
    Application of the transient hot-wire method to gases at low pressures (1994)
    Springer
    International journal of thermophysics 15 (1994), S. 141-153 
    Details
    ISSN: 1572-9567
    Keywords: argon ; low pressure ; refrigerants ; thermal conductivity ; transient hot-wire method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The need to determine the thermal conductivity of non-ozone-depleting refrigerants implies measurements at pressures below 10 bar in the gaseous phase. In order to apply the transient hot-wire method with proven accuracy to this state, possible sources of systematic errors in the measurements have been carefully assessed theoretically and experimentally. The influence of the finite heat capacity of the hot wire and of the isothermal outer wall of the cell have been identified to affect the measurements substantially. An improved correction method to account for the wire heat capacity is presented, as well as criteria to choose the parameters in the experiments in order to avoid errors due to the outer boundary and due to the finite wire length. The results are presented in dimensionless quantities, and as an example, they are discussed for argon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01439251
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  • 4
    Electronic Resource
    Electronic Resource
    Transport properties of 1,1-difluoroethane (R152a) (1996)
    Springer
    International journal of thermophysics 17 (1996), S. 731-757 
    Details
    ISSN: 1572-9567
    Keywords: 1,1-difluoroethane ; correlation ; critical region ; HFC-152a ; R152a ; thermal conductivity ; transport properties ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Based on reliable. carefully selected data sets. equations for the thermal conductivity and the viscosity of the refrigerant R 112a are presented. They are valid at temperatures from 240 to 440 K, pressures up to 20 MPa. and densities up to 1050 kg · m−3. including the critical region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01439187
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  • 5
    Electronic Resource
    Electronic Resource
    Cubic equations of state for transport properties (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 333-356 
    Details
    ISSN: 1572-9567
    Keywords: equation of state ; thermal conductivity ; transport equation of state ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A method is presented for the prediction of the background contribution of residual thermal conductivities and residual viscosities of nonpolar or slightly polar substances. The method is based on the concept of transport equations of state describing the transport properties in terms of pressure and temperature by pressure explicit equations similar to thermal equations of state. The transport equation of state is derived from a generalized cubic thermal equation of state and a universal function for the density dependence of the residual part of the transport properties. A comparison of calculated and recommended values of the thermal conductivity of 35 and the viscosity of 23 substances yields an absolute average deviation of 6% for the thermal conductivity and of 5% for the viscosity. The Maxwell condition is applied to the generalized transport equation of state to predict consistently the transport properties along the vapor-liquid coexistence curve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500756
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  • 6
    Electronic Resource
    Electronic Resource
    Thermal conductivity of R134a and R141b within the temperature range 240–307 K at the saturation vapor pressure (1993)
    Springer
    International journal of thermophysics 14 (1993), S. 173-181 
    Details
    ISSN: 1572-9567
    Keywords: R134a ; R141b ; refrigerants ; thermal conductivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New, absolute values of the thermal conductivity of two refrigerants, R134a and R141b, in the liquid phase at saturation are reported. The measurements have been performed in transient hot-wire instruments making use of electrically insulated tantalum wires within the temperature range 240–307 K. The results are estimated to have an accuracy of ±1%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00507806
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  • 7
    Electronic Resource
    Electronic Resource
    The MIDAS Data-Bank System for the transport properties of fluids (1986)
    Springer
    International journal of thermophysics 7 (1986), S. 973-986 
    Details
    ISSN: 1572-9567
    Keywords: correlation ; data bank ; fluid mixtures ; oxygen ; pure fluids ; transport equation of state ; thermal conductivity ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The development of the MIDAS Data-Bank System from its origin as part of the first DECHEMA properties data project in 1977 is described. The system concentrates the rapidly increasing amount of data for the viscosity and thermal conductivity for pure fluids and fluid mixtures by evaluation of the most reliable data sets. The data sets are represented by density-temperature correlations which are the customary method to correlate transport properties. To allow for a direct calculation of the transport properties from given pressures and temperatures, a new type of equation has been developed. As an example, the simultaneous representation of the viscosity and thermal conductivity of oxygen by one transport equation of state is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00503852
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  • 8
    Electronic Resource
    Electronic Resource
    Analysis of the Photoacoustic Detector Signal for Thermal Diffusivities of Gases (1998)
    Springer
    International journal of thermophysics 19 (1998), S. 1099-1109 
    Details
    ISSN: 1572-9567
    Keywords: photoacoustic detector ; thermal conductivity ; thermal diffusivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A resonant and a nonresonant photoacoustic detector were used to determine thermal diffusivities of gases. With a nonresonant detector thermal diffusivities can be determined in a wide range between 10−3 and 10−7 m2·s−1, whereas experiments with the resonant detector deliver thermal diffusivities in a range that is about a factor of 100 smaller. As refrigerants—HFCs, HCFCs, and hydrocarbons—are absorbents in the infrared at a wavelength of 3.39 μm, their thermal diffusivity can be determined without the addition of a trace gas, particularly at pressures below 0.01 MPa. At pressures above 0.1 MPa, the addition of ammonia as a trace gas is recommended. The absorption wavelength is then 1.531 μm. A simulation model for the nonresonant photoacoustic detector is presented for the design of a detector and for an extended error analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022685524925
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