THERMAL CONDUCTIVITY OF SOLIDS AT HIGH TEMPERATURES AND HIGH PRESSURES

2007 ◽  
Vol 21 (25) ◽  
pp. 4419-4427 ◽  
Author(s):  
S. K. SHARMA ◽  
S. K. SRIVASTAVA ◽  
B. S. SHARMA
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
High Temperatures ◽  
High Pressures ◽  
Equations Of State ◽  
Conductivity Equation ◽  
Thermoelastic Properties ◽  
Thermal Conductivity Equation ◽  
Wide Range ◽  
Low Pressures

In the present study, we have extended the model due to Tang1 based on the thermal conductivity equation due to Leibfried and Schlomann12 so as to make it applicable for a wide range of pressures and temperatures. We have used the Stacey14,15 equations of state (EOS) for determining the thermoelastic properties of NaCl , KCl and Al 2 O 3 at high pressures and high temperatures. These are used to estimate the variations of thermal conductivity with the change in pressure along different isotherms at selected temperatures. The results thus obtained are compared with the values derived from relations, which reproduced available experimental data well at low temperatures and low pressures. Experimental data at high temperatures and high pressures are not available. A close agreement between the two sets of data reveals the validity of the present work.

Estimation of thermal conductivity of PP/Al(OH)3/Mg(OH)2 composites

2012 ◽  
Vol 32 (6-7) ◽  
pp. 401-406
Author(s):  
Ji-Zhao Liang
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Volume Fraction ◽  
Measured Data ◽  
Measuring Instrument ◽  
Conductivity Equation ◽  
Experimental Conditions ◽  
Thermal Conductivity Equation ◽  
Pp Composites

Abstract The thermal conductivity of polypropylene (PP) composites filled with Al(OH)3 and Mg(OH)2 was measured by means of the stable flat measuring instrument at different testing temperatures. The effective thermal conductivity of the composites was estimated by applying the thermal conductivity equation proposed previously, and the estimations were compared with the experimental measured data under the same experimental conditions. The results showed that the calculations and measurements of the effective thermal conductivity were close to each other when the volume fraction of the Al(OH)3/Mg(OH)2 powder was <10.4%. Moreover, the effective thermal conductivity of the composites was estimated using the Russell model and the Maxwell-Eucken model, and the predictions were compared with the experimental data and the estimations of this equation. It was found that the estimations of this equation were closer to the experimental data than those of the Russell model and Maxwell-Eucken model.

Wide-range equations of state for organic liquids

2007 ◽  
Vol 5 ◽  
pp. 113-120 ◽  
Author(s):  
R.Kh. Bolotnova
Keyword(s):  
High Pressures ◽  
Equations Of State ◽  
Organic Liquids ◽  
Liquid Phases ◽  
Wide Range ◽  
High Pressures And Temperatures

The method of construction the wide-range equations of state for organic liquids, describing the gas and liquid phases including dissociation and ionization which occurs during an intense collapse of steam bubbles and accompanied by ultra-high pressures and temperatures, is proposed.

scholarly journals Equation of state for rhodium at high pressures

2021 ◽  
Vol 2057 (1) ◽  
pp. 012118
Author(s):  
K V Khishchenko
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Equation Of State ◽  
Internal Energy ◽  
Specific Volume ◽  
High Pressures ◽  
Thermodynamic Characteristics ◽  
Wide Range ◽  
Hydrodynamic Processes

Abstract An equation of state has been developed for rhodium in a wide range of changes in the specific volume and internal energy. The results of calculations of the thermodynamic characteristics of this metal are presented in comparison with the available experimental data at high pressures. This equation of state can be used in the numerical simulation of hydrodynamic processes under intense impulse influences on matter.

scholarly journals Relationship between the Transport Coefficients of Polar Substances and Entropy

Entropy ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 13
Author(s):  
Ivan Anashkin ◽  
Sergey Dyakonov ◽  
German Dyakonov
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Diffusion Coefficient ◽  
High Pressures ◽  
Thermal Conductivity Coefficient ◽  
Good Description ◽  
Transport Coefficients ◽  
Viscosity Coefficient ◽  
Wide Region ◽  
Good Agreement

An expression is proposed that relates the transport properties of polar substances (diffusion coefficient, viscosity coefficient, and thermal conductivity coefficient) with entropy. To calculate the entropy, an equation of state with a good description of the properties in a wide region of the state is used. Comparison of calculations based on the proposed expressions with experimental data showed good agreement. A deviation exceeding 20% is observed only in the region near the critical point as well as at high pressures.

Thermal Conductivity of Ultra Thin Single Crystal Silicon Layers: Part II — Experimental Data and Modeling at High Temperatures

2004 ◽  
Author(s):  
Wenjun Liu ◽  
Mehdi Asheghi ◽  
K. E. Goodson
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Single Crystal ◽  
High Temperatures ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Silicon On Insulator ◽  
Boltzmann Transport ◽  
Crystal Silicon ◽  
Strained Si

Simulations of the temperature field in Silicon-on-Insulator (SOI) and strained-Si transistors can benefit from experimental data and modeling of the thin silicon layer thermal conductivity at high temperatures. This work presents the first experimental data for 20 and 100 nm thick single crystal silicon layers at high temperatures and develops algebraic expressions to account for the reduction in thermal conductivity due to the phonon-boundary scattering for pure and doped silicon layers. The model applies to temperatures range 300–1000 K for silicon layer thicknesses from 10 nm to 1 μm (and even bulk) and agrees well with the experimental data. In addition, the model has an excellent agreement with the predictions of thin film thermal conductivity based on thermal conductivity integral and Boltzmann transport equation, although it is significantly more robust and convenient for integration into device simulators. The experimental data and predictions are required for accurate thermal simulation of the semiconductor devices, nanostructures and in particular the SOI and strained-Si transistors.

Effect of Heat Flux on Droplet Entrainment Using Annular Flow Dryout Model

2010 ◽  
Author(s):  
Masroor Ahmad ◽  
Evgeniy Burlutskiy ◽  
Simon P. Walker ◽  
Geoffrey F. Hewitt
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
High Pressure ◽  
Liquid Film ◽  
Annular Flow ◽  
High Pressures ◽  
Droplet Entrainment ◽  
Annular Film ◽  
Low Pressures ◽  
Flow Experiments

Annular film dryout depends upon the competition of entrainment, deposition and evaporation processes between the droplet-laden core and wall liquid film. In this paper, effect of heat flux on droplet entrainment is analyzed by modeling different low and high pressure diabatic annular flow experiments numerically using an annular flow dryout model (AFM). Overall, the AFM predicted the experimental data reasonably accurately. It is concluded that at high pressures increasing heat flux may enhance net entrainment considerably but this effect diminishes at low pressures.

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