On the Determination of Surface Thermal Conductivities

1922 ◽  
Vol 19 (4) ◽  
pp. 404-405
Author(s):  
Letha A. Smith
Keyword(s):  
Thermal Conductivities

Determination of thermal conductivities of solid and liquid phases for rich-Sn compositions of Sn-Mg alloy

2012 ◽  
Vol 18 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Fatma Meydaneri ◽  
Mehmet Gündüz ◽  
Mehmet Özdemir ◽  
Buket Saatçi
Keyword(s):  
Mg Alloy ◽  
Liquid Phases ◽  
Thermal Conductivities

Determination of Thermal Conductivity of Soils: A Need for Computing Heat Loss Through Buried Submarine Pipelines

1982 ◽  
Vol 22 (04) ◽  
pp. 558-562 ◽  
Author(s):  
P.C. Rawat ◽  
S.L. Agarwal
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Crude Oil ◽  
Rheological Properties ◽  
Heat Loss ◽  
Experimental Results ◽  
Dry Density ◽  
Empirical Relationships ◽  
Thermal Conductivities

Abstract An important parameter required for computing heat loss through buried submarine pipelines transporting crude oil is the thermal conductivity of soils. This paper describes an apparatus designed for determination of the thermal conductivity of soils at the desired moisture/ density condition in the laboratory under steady-state conditions. Experimental results on the three soils studied show that thermal conductivity increases as dry density increases at a constant moisture content and that it increases as water content increases at constant dry density. These results confirm the trends isolated earlier by Kersten. The experimental results are compared with the available empirical relationships. Kersten's relation is observed to predict the thermal conductivity of these soils reasonably. The predictions from Makowski and Mochlinski's relation (quoted by Szilas) are not good but improve if the sum of silt and clay fractions is treated as a clay fraction in the computation. Introduction Submarine pipelines are used extensively for transporting crude oil from offshore to other pipelines offshore or onshore. These pipelines usually are steel pipes covered with a coating of concrete. They often are buried some depth below the mudline. The rheological properties of different crude oils vary, and their viscosities increase with a decrease in temperature. Below some temperature, the liquid oil tends to gel. Therefore, for efficient transportation, the crude must be at a relatively high temperature so that it has a low viscosity. The temperature of the soil/water system surrounding a submarine pipeline is usually lower than that of oil. This temperature difference induces heat to flow from the oil to the environment, and the temperature of the oil decreases as it travels along the length of the pipeline. One must ensure that this temperature reduction does not exceed desirable limits dictated by the rheological properties of oil and by the imperatives of efficient economic properties of oil and by the imperatives of efficient economic transportation. Thus the analytical problem is to predict the temperature of crude in the pipeline some distance away from the input station. To do so, knowledge of the overall heat transfer coefficient for the pipeline is required, for which, in turn, it is necessary to know the thermal conductivities of the oil, the pipeline materials and its coating, and the soil. This paper presents thermal conductivities of soils determined in the laboratory under steady-state conditions and also presents a comparison of the test results of three soils with values determined from existing empirical relationships. Literature Review Heat moves spontaneously from higher to lower temperatures. In a completely dry porous body, transmission of heat can take place not only by conduction through the solid framework of the body and the air in the pores but also by convection and radiation between the walls of a pore and by macro- and microdistillation. In soils, however, it can be ascribed essentially to conduction, a molecular phenomenon that can be expressed in terms of experimentally determined coefficients of conductivity or resistivity, although these actually may include microdistillation and other mechanisms. SPEJ p. 558

scholarly journals Experimental determination of the thermal conductivities of gases

1926 ◽  
Vol 110 (753) ◽  
pp. 91-122 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Specific Heat ◽  
Experimental Determination ◽  
Dynamic Theory ◽  
Great Accuracy ◽  
Constant Volume ◽  
Order Of Accuracy ◽  
Molecular Collision ◽  
Thermal Conductivities

The analysis of the dynamic theory of gases has indicated an interesting relation between the viscosity η , the thermal conductivity K, and the specific heat at constant volume C c of a gas. This relation is represented by the expression K = f . C c . η , in which the factor f depends upon the law of force operative in molecular collision, and is known if K, C c , and η can be determined experimentally. In view of its importance in this respect, and also from the fact that great accuracy and consistency of measurement are possible in modern determinations of the viscosity of gases, the importance of the development of a method by which the conductivity can be measured with the same order of accuracy demands increasing attention.

A New Method for Simultaneous Determination of Anisotropic Thermal Conductivities Based on Two-Dimensional Analysis

2001 ◽  
Vol 40 (Part 1, No. 1) ◽  
pp. 388-392
Author(s):  
Hiroyuki Fujishiro ◽  
Tatsuya Okamoto ◽  
Manabu Ikebe ◽  
Koichi Hirose
Keyword(s):  
Simultaneous Determination ◽  
Dimensional Analysis ◽  
New Method ◽  
Two Dimensional ◽  
Thermal Conductivities
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