Calculation of the coefficient of thermal conductivity of a chemically reacting gas mixture of methane and hydrogen in the temperature range 1000?6000�K

1978 ◽  
Vol 35 (1) ◽  
pp. 773-777
Author(s):  
A. N. Laktyushin ◽  
T. V. Laktyushina ◽  
O. I. Yas'ko
Keyword(s):  
Thermal Conductivity ◽  
Gas Mixture ◽  
Temperature Range ◽  
Coefficient Of Thermal Conductivity ◽  
Chemically Reacting

Thermal conductivity of a chemically reacting ternary gas mixture

1965 ◽  
Vol 9 (6) ◽  
pp. 446-448 ◽  
Author(s):  
M. I. Verba ◽  
V. D. Portnov
Keyword(s):  
Thermal Conductivity ◽  
Gas Mixture ◽  
Chemically Reacting

SOME PHYSICAL PROPERTIES OF A SAMPLE OF ALBERTA BITUMINOUS SAND

1944 ◽  
Vol 22f (6) ◽  
pp. 174-180 ◽  
Author(s):  
K. A. Clark
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Specific Heat ◽  
Mineral Content ◽  
Pore Space ◽  
Calorific Value ◽  
Natural State ◽  
Temperature Range ◽  
Coefficient Of Thermal Conductivity ◽  
Bitumen Content

Some physical properties of a sample of bituminous sand from the Abasand Oils Ltd. quarry have been determined. The sample contained about 17% bitumen and 1% water. The porosity of the sample in its natural state of packing was 39 to 40%, while saturation of the pore space with bitumen was 80 to 85% and with water, 3.5 to 4.5%. The coefficient of thermal conductivity of the sample in its natural state of packing was 0.0035 in c.g.s. units and at 45 °C. The specific heat of the bitumen content of the sample was 0.35 and of the mineral content, 0.18 for the temperature range 0° to 100 °C. The bitumen had a calorific value of 17,860 B.t.u. per lb.

Measurement of apparent thermal conductivity of regenerator materials in 4-20 K temperature range

Cryogenics ◽  
2021 ◽  
pp. 103300
Author(s):  
Yang Biao ◽  
Xi Xiaotong ◽  
Liu Xuming ◽  
Xu Xiafan ◽  
Chen Liubiao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Range ◽  
Apparent Thermal Conductivity

Effects of Nb doping on thermoelectric properties of Zn4Sb3 at high temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 430-435 ◽  
Author(s):  
D. Li ◽  
H.H. Hng ◽  
J. Ma ◽  
X.Y. Qin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Performance ◽  
Temperature Range ◽  
A Value ◽  
Nb Doping ◽  
Thermal Conductivities

The thermoelectric properties of Nb-doped Zn4Sb3 compounds, (Zn1–xNbx)4Sb3 (x = 0, 0.005, and 0.01), were investigated at temperatures ranging from 300 to 685 K. The results showed that by substituting Zn with Nb, the thermal conductivities of all the Nb-doped compounds were lower than that of the pristine β-Zn4Sb3. Among the compounds studied, the lightly substituted (Zn0.995Nb0.005)4Sb3 compound exhibited the best thermoelectric performance due to the improvement in both its electrical resistivity and thermal conductivity. Its figure of merit, ZT, was greater than the undoped Zn4Sb3 compound for the temperature range investigated. In particular, the ZT of (Zn0.995Nb0.005)4Sb3 reached a value of 1.1 at 680 K, which was 69% greater than that of the undoped Zn4Sb3 obtained in this study.

ON MEASUREMENT OF THERMAL CONDUCTIVITY AT HIGH TEMPERATURES

1961 ◽  
Vol 39 (7) ◽  
pp. 1029-1039 ◽  
Author(s):  
M. J. Laubitz
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
High Temperatures ◽  
Mathematical Analysis ◽  
Temperature Range ◽  
Linear Heat ◽  
Flow Systems

A method is given for exact mathematical analysis of linear heat flow systems used in measuring thermal conductivity at high temperatures. It is shown that a popular version of such a system is very sensitive to the alignment of its components, which seriously limits the temperature range of its satisfactory use.

Measurements of the thermal conductivity of R11 and R12 in the temperature range 250?340 K at pressures up to 30 MPa

1992 ◽  
Vol 13 (5) ◽  
pp. 735-751 ◽  
Author(s):  
M. J. Assael ◽  
E. Karagiannidis ◽  
W. A. Wakeham
Keyword(s):  
Thermal Conductivity ◽  
Temperature Range

Thermal Conductivity and Prandtl Number of Carbon Dioxide and Carbon-Dioxide Air Mixtures at One Atmosphere

1961 ◽  
Vol 83 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Jerome L. Novotny ◽  
Thomas F. Irvine
Keyword(s):  
Carbon Dioxide ◽  
Thermal Conductivity ◽  
Prandtl Number ◽  
Maximum Error ◽  
Intermolecular Force ◽  
Temperature Range ◽  
Average Temperature ◽  
Pure Carbon ◽  
Prandtl Numbers ◽  
Pure Carbon Dioxide

By measuring laminar recovery factors in a high velocity gas stream, experimental determinations were made of the Prandtl number of carbon dioxide over a temperature range from 285 to 450 K and of carbon-dioxide air mixtures at an average temperature of 285 K with a predicted maximum error of 1.5 per cent. Thermal conductivity values were deduced from these Prandtl numbers and compared with literature values measured by other methods. Using intermolecular force constants determined from literature experimental data, viscosities, thermal conductivities, and Prandtl numbers were calculated for carbon-dioxide air mixtures over the temperature range 200 to 1500 deg for mixture ratios from pure air to pure carbon dioxide.

TRIGGERING OF DETONATION PROCESSES IN PROPULSION CHAMBER

2021 ◽  
Vol 14 (2) ◽  
pp. 40-45
Author(s):  
D. V. VORONIN ◽  
Keyword(s):  
Thermal Conductivity ◽  
Numerical Modeling ◽  
Gas Flow ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Chemically Reacting ◽  
Plane Disk ◽  
And Diffusion

The Navier-Stokes equations have been used for numerical modeling of chemically reacting gas flow in the propulsion chamber. The chamber represents an axially symmetrical plane disk. Fuel and oxidant were fed into the chamber separately at some angle to the inflow surface and not parallel one to another to ensure better mixing of species. The model is based on conservation laws of mass, momentum, and energy for nonsteady two-dimensional compressible gas flow in the case of axial symmetry. The processes of viscosity, thermal conductivity, turbulence, and diffusion of species have been taken into account. The possibility of detonation mode of combustion of the mixture in the chamber was numerically demonstrated. The detonation triggering depends on the values of angles between fuel and oxidizer jets. This type of the propulsion chamber is effective because of the absence of stagnation zones and good mixing of species before burning.

Determination of the Thermal Properties of a PCB by Coupled Numerical and Experimental Approach

2020 ◽  
Author(s):  
Yener Usul ◽  
Mustafa Özçatalbaş
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Numerical Analysis ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermal Analyses ◽  
Analysis Model ◽  
Linear Temperature ◽  
Coefficient Of Thermal Conductivity

Abstract Increasing demand for usage of electronics intensely in narrow enclosures necessitates accurate thermal analyses to be performed. Conduction based FEM (Finite Element Method) is a common and practical way to examine the thermal behavior of an electronic system. First step to perform a numerical analysis for any system is to set up the correct analysis model. In this paper, a method for obtaining the coefficient of thermal conductivity and specific heat capacity of a PCB which has generally a complex composite layup structure composed of conductive layers, and dielectric layers. In the study, above mentioned properties are obtained performing a simple nondestructive experiment and a numerical analysis. In the method, a small portion of PCB is sandwiched from one side at certain pressure by jaws. A couple of linear temperature profiles are applied to the jaws successively. Unknown values are tuned in the analysis model until the results of FEM analysis and experiment match. The values for the coefficient of thermal conductivity and specific heat capacity which the experiment and numerical analysis results match can be said to be the actual values. From this point on, the PCB whose thermal properties are determined can be analyzed numerically for any desired geometry and boundary condition.

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