General Solutions for Pistonlike Displacement of Compressible Fluids in Porous Media

1985 ◽  
Vol 107 (4) ◽  
pp. 523-526 ◽  
Author(s):  
S. H. Advani ◽  
J. S. Torok ◽  
J. K. Lee
Keyword(s):  
Coal Gasification ◽  
Compressible Fluids ◽  
Fracture Face ◽  
Underground Coal Gasification ◽  
Interface Motion ◽  
One Dimensional ◽  
Special Solutions ◽  
The One ◽  
Step Step ◽  
Constant Slope

Exact solutions for the one-dimensional problem of a compressible fluid having a time-dependent pressure at the source (fracture face) and displacing a compressible reservoir fluid are generated. Special solutions for various cases represented by step, step with constant slope front, and sinusoidal pressure variations at the fracture face are derived. Numerical results and trends for fluid interface motion are revealed for selected cases. The applicability of the presented solutions to hydraulic fracturing is discussed. In addition, response solutions for problems in reservoir mechanics, underground coal gasification, and nuclear waste management can be similarly investigated.

TEMPERATUREREGIME OF COAL BED BY UNDERGROUND COAL GASIFICATION IN THE FILTRATION CHANNEL

2020 ◽  
Vol 2 (1) ◽  
pp. 309-318
Author(s):  
A.N. KACHURIN ◽  
◽  
A.B. KOPILOV ◽  
G.V. FRIDLENDER ◽  
M.P. GANIN ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Coal Bed ◽  
State University ◽  
Underground Coal Gasification ◽  
Unsteady Temperature ◽  
One Dimensional ◽  
Underground Gasification ◽  
Unsteady Temperature Field ◽  
The One ◽  
Thermal Preparation

A mathematical model of the temperature regime of a coal bed during underground coal gasification in a filtration channel for new geotechnologies of Tula State University is developed. It is proposed to describe the unsteady temperature field of the coal seam with the one-dimensional heat conduction equation with the heat sink that depends on the temperature of the coal bed. The equation is solved for semi-infinite space. The results of computational experiments have shown that the temperature front from the fire face moves deep into the coal bed. Consequently, in the process of underground gasification, pre-heating of coal in the gasified block and thermal preparation take place. Quite quickly, after the formation of stable combustion of coal in the fire face, a stationary temperature profile is established.

Control oriented modeling and optimization of one dimensional packed bed model of underground coal gasification

2014 ◽  
Vol 24 (1) ◽  
pp. 269-277 ◽  
Author(s):  
Ali Arshad Uppal ◽  
Aamer Iqbal Bhatti ◽  
Erum Aamir ◽  
Raza Samar ◽  
Shahid Ahmed Khan
Keyword(s):  
Coal Gasification ◽  
Packed Bed ◽  
Underground Coal Gasification ◽  
One Dimensional ◽  
Modeling And Optimization

Radial Flow of Compressible Fluids Between Discs

1965 ◽  
Vol 16 (3) ◽  
pp. 282-288
Author(s):  
Tsung Yen Na
Keyword(s):  
Compressible Fluid ◽  
Radial Flow ◽  
Numerical Solutions ◽  
Supersonic Flows ◽  
Compressible Fluids ◽  
One Dimensional ◽  
The One

SummaryNumerical solutions are obtained for the one-dimensional radial flow of a compressible fluid between parallel discs. A general discussion of the variations of pressure, density, velocity and temperature along the radius of the disc is then given. The present investigation covers both subsonic and supersonic flows, a range not previously covered in the literature.

Heat Transfer at an Evaporating Front in Porous Media

2009 ◽  
Author(s):  
V. K. Chaitanya Pakala ◽  
O. A. Plumb
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Coal Gasification ◽  
Solid Phase ◽  
Front Propagation ◽  
Porous Matrix ◽  
Equation Model ◽  
Local Thermal Equilibrium ◽  
Underground Coal Gasification ◽  
The One

Evaporating fronts propagate through porous media during drying processes, underground coal gasification, geothermal energy production from hot dry rock, and around nuclear waste repositories. Present work will focus on the one-dimensional heat transfer at the interface between vapor saturated porous matrix and water saturated porous region and evaluate the conditions for which various approximations yield an accurate representation of front velocity. An implicit finite difference scheme is utilized to simulate the propagation of an evaporating front in a porous medium saturated with water and undergoing the phase change process. The assumption of local thermal equilibrium (LTE) which results in a one-equation model and a simple two-equation model that does not assume LTE are examined by comparison with a quasi-analytic numerical model. We consider the case for low Reynolds number, hence Nusselt number is assumed constant. Results illustrate that the one-equation model does not yield accurate results even if the length scale for diffusion in the solid phase is relatively small. The one-equation model predicts faster front propagation than the two-equation model. It is illustrated that the one-equation model yields satisfactory results only when thermophysical properties characterized by the volume weighted ratio of thermal diffusivities is reduced to an order of magnitude less than those for the applications of interest. In addition, consistent with the established “rule of thumb”, for Biot < 0.1, the traditional two-equation model which makes the lumped capacitance assumption for the solid phase compares well with a two-equation model that more accurately predicts the time dependent diffusion in the solid phase using Duhamel’s theorem.

Optimization and control of one dimensional packed bed model of underground coal gasification

2015 ◽  
Vol 35 ◽  
pp. 11-20 ◽  
Author(s):  
Ali Arshad Uppal ◽  
Aamer Iqbal Bhatti ◽  
Erum Aamir ◽  
Raza Samar ◽  
Shahid Ahmed Khan
Keyword(s):  
Coal Gasification ◽  
Packed Bed ◽  
Underground Coal Gasification ◽  
One Dimensional ◽  
Optimization And Control ◽  
And Control

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

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