Thermal conductivity, thermal gradient, and heat-flow estimations for the Smackover Formation, southwest Arkansas

2016 ◽  
pp. 95-114
Author(s):  
Lea M. Nondorf
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Gradient ◽  
Smackover Formation

Geothermal Data from the Granduc Area, Northern Coast Mountains of British Columbia

1972 ◽  
Vol 9 (10) ◽  
pp. 1333-1337 ◽  
Author(s):  
W. H. Mathews
Keyword(s):  
Thermal Conductivity ◽  
British Columbia ◽  
Heat Flow ◽  
Thermal Gradient ◽  
Temperature Measurements ◽  
Simplified Model ◽  
Northern Coast ◽  
Rock Glacier ◽  
Coast Mountains

Temperature measurements have been obtained from 80 points along the Granduc haulage tunnel, at depths of as much as 1.5 km below the surface. These fit, within 1 °C, a simplified model assuming, among other things, uniform thermal conductivity of the rocks and a temperature at rock–glacier contacts of 0 °C. For these assumptions a generalized thermal gradient (with effects of topographic irregularity removed) is about 26 mK m−1 (26 °C/km). With the thermal conductivity of a suite of rocks from the tunnel averaging 2.72 ± 12 W m−1K−1 (6.50 ±.28 cal/cm s °C) present heat flow of about 73 mW m−2 (1.74 μcal/cm2 s) can be derived.

GEOLOGICAL AND GEOPHYSICAL STUDY FOR ELABORATION OF GEOTHERMAL MODEL IN ORADEA-BAILE FELIX AREA

2020 ◽  
Author(s):  
Laurențiu Asimopolos ◽  
Natalia-Silvia Asimopoli
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Gradient ◽  
Thermal Inertia ◽  
Geothermal Gradient ◽  
Point Of View ◽  
Hot Water ◽  
Thermal Methods ◽  
Thermal Anomalies ◽  
Average Value

Thermal methods consist of measuring thermal gradient and satellite data, which can be used to determine the Earth's surface temperature and thermal inertia of surficial materials, of thermal infrared radiation emitted at the Earth's surface. Thermal gradient measuring, with a knowledge of the thermal conductivity provides a measure of heat flow. Conditions that may increase or decrease and heat flow are influenced by hydrologic, topographic factors and anomalous thermal conductivity. Also, oxidation of sulphide bodies in-place or on waste deposits, if sufficiently rapid, can generate thermal anomalies, which can provide a measure of the amount of metal being released to the environment. The geothermal gradient on the territory of Romania, the increase of the temperature with the depth, has an average value of 2.5°-3°C/100m, which corresponds to a temperature of 100° C at 3000 m deep. There are many areas where the value of the geothermal gradient differs considerably from this average. For example, in areas where the rock plate suffered rapid dips and the basin was filled with sediment "very young "from a geological point of view, the geothermal gradient may be less than 1° C/100m. On the other hand, in other geothermal areas the gradient exceeds much this average. These areas are true underground thermal reservoirs of potentially high geothermal energy which under certain favourable conditions can be exploited to serve heating installations and domestic hot water systems. The geothermal prospecting for the entire territory of Romania, carried out by temperature measurements allowed the development of geothermal maps, highlighting the temperature distribution at different depths. Geophysical data obtained through various methods and geophysical modelling provide generalized and non-unique solutions to the geometry of underground geological relations as well as to the physical characteristics of different formations. The non-uniqueness of these models (solutions to the direct problem) arises from the impossibility of knowing the boundary conditions between different strata, which together with the propagation equations of the different fields (depending on the geophysical method used for the investigation of the basement) form the systems that offer the solutions of the model

Irreversible Thermodynamics of the Thermal Characteristics of Porous Insulators

1962 ◽  
Vol 29 (2) ◽  
pp. 425-428 ◽  
Author(s):  
R. G. Mokadam
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Temperature Gradient ◽  
Pressure Gradient ◽  
Convective Heat ◽  
Frictional Force ◽  
Thermal Gradient ◽  
Gas Flow ◽  
Irreversible Processes ◽  
Set Up

The entropy equation contains terms which indicate entropy generation due to two irreversible processes: Heat flow in the presence of temperature gradient, and gas flow in the presence of frictional force. These flows are assumed to be linearly dependent upon the temperature gradient and the frictional force. This assumption includes two cross phenomena: Convective heat transfer (set up by pressure gradient), and free convection (set up by temperature gradient). They are interdependent. Usually the frictional force is equal to the gaseous-phase pressure gradient. When this pressure gradient is zero, the heat flow depends only upon the thermal gradient. By entrapping the gas in the porous medium, the gas flow is stopped. This gives rise to a pressure gradient which sets up a convective heat flow opposing that due to thermal gradient. Consequently, the thermal conductivity of the porous insulator decreases. Experimental work on Tritex insulation material indicated a 22 per cent decrease in thermal conductivity.

AN INSTRUMENT FOR MEASURING HEAT FLOW, TEMPERATURE, AND THERMAL CONDUCTIVITY IN THE LUNAR SURFACE LAYER

1970 ◽  
Author(s):  
A. E. Wechsler ◽  
E. M. Drake ◽  
F. E. Ruccia ◽  
J. E. McCullough ◽  
P. Felsenthal ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Surface Layer ◽  
Heat Flow ◽  
Lunar Surface ◽  
Flow Temperature

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.

Adiabatic Heat Flow in Mercury with a Fe-8.5wt%Si Core

2021 ◽  
Author(s):  
Meryem Berrada ◽  
Richard Secco ◽  
Wenjun Yong
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Internal Structure ◽  
High Pressures ◽  
Inner Core ◽  
Thermal Evolution ◽  
The Core ◽  
Thermally Driven ◽  
Wire Method ◽  
Core Conditions

<p>Recent theoretical studies have tried to constrain Mercury’s internal structure and composition using thermal evolution models. The presence of a thermally stratified layer of Fe-S at the top of an Fe-Si core has been suggested, which implies a sub-adiabatic heat flow on the core side of the CMB. In this work, the adiabatic heat flow at the top of the core was estimated using the electronic component of thermal conductivity (k<sub>el</sub>), a lower bound for thermal conductivity. Direct measurements of electrical resistivity (ρ) of Fe-8.5wt%Si at core conditions can be related to k<sub>el</sub> using the Wiedemann-Franz law. Measurements were carried out in a 3000 ton multi-anvil press using a 4-wire method. The integrity of the samples at high pressures and temperatures was confirmed with electron-microprobe analysis of quenched samples at various conditions. Unexpected behaviour at low temperatures between 6-8 GPa may indicate an undocumented phase transition. Measurements of ρ at melting seem to remain constant at 127 µΩ·cm from 10-24 GPa, on both the solid and liquid side of the melting boundary. The adiabatic heat flow at the core side of Mercury’s core-mantle boundary is estimated between 21.8-29.5 mWm<sup>-2</sup>, considerably higher than most models of an Fe-S or Fe-Si core yet similar to models of an Fe core. Comparing these results with thermal evolution models suggests that Mercury’s dynamo remained thermally driven up to 0.08-0.22 Gyr, at which point the core became sub-adiabatic and stimulated a change from dominant thermal convection to dominant chemical convection arising from the growth of an inner core. Simply considering the internal structure of Mercury, these results support the capture of Mercury into a 3:2 resonance orbit during the thermally driven era of the dynamo.</p>

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