Solution of the flow and mass transport equations by means of spectral elements

1993 ◽  
Vol 29 (9) ◽  
pp. 3135-3144 ◽  
Author(s):  
P. Goblet ◽  
E. Cordier
Keyword(s):  
Mass Transport ◽  
Transport Equations ◽  
Spectral Elements ◽  
Flow And Mass Transport

scholarly journals Stochastic Risk and Uncertainty Analysis for Shale Gas Extraction in the Karoo Basin of South Africa

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Abdon Atangana ◽  
Gerrit van Tonder
Keyword(s):  
South Africa ◽  
Mass Transport ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Transport Equations ◽  
Upward Migration ◽  
Karoo Basin ◽  
Fracking Fluid ◽  
Stochastic Risk ◽  
Flow And Mass Transport

We made use of groundwater flow and mass transport equations to investigate the crucial potential risk of water pollution from hydraulic fracturing especially in the case of the Karoo system in South Africa. This paper shows that the upward migration of fluids will depend on the apertures of the cement cracks and fractures in the rock formation. The greater the apertures, the quicker the movement of the fluid. We presented a novel sampling method, which is the combination of the Monte Carlo and the Latin hypercube sampling. The method was used for uncertainties analysis of the apertures in the groundwater and mass transport equations. The study reveals that, in the case of the Karoo, fracking will only be successful if and only if the upward methane and fracking fluid migration can be controlled, for example, by plugging the entire fracked reservoir with cement.

Simulation of Flow and Mass Transport in a Meander Microchannel Subject to Electroosmotic Pumping

2003 ◽  
Author(s):  
Dominik P. J. Barz ◽  
Peter Ehrhard
Keyword(s):  
Mass Transport ◽  
Double Layers ◽  
Complex Flow ◽  
Electrical Field ◽  
Electrical Fields ◽  
Electrical Double Layers ◽  
Electroosmotic Pumping ◽  
Pressure Driven Flow ◽  
Flow And Mass Transport ◽  
Pressure Driven

We have investigated the flow and mass transport within an electroosmotically-pumped incompressible liquid through a meander microchannel system. We employ two-dimensional, time-dependent Finite Element simulations in conjunction with a matched asymptotic treatment of the electrical double layers. The electroosmotic pumping is realized for two idealized and two realistic electrical fields, while a pressure-driven flow is used for comparison. We focus on the aspects of the electroosmotic transport. We find for most of the electroosmotically-driven cases rather complex flow fields, involving recirculation regions. These recirculation regions in all cases increase dispersion. (i) The least dispersion is associated with a plug-type velocity profile, which is obtained for an idealized purely wall-tangential orientation of the electrical field. (ii, iii) We find that both, the idealized horizontal electrical field and the real electrical field between two vertical plates give considerably higher dispersion than the pressure-driven flow. Vertical plate electrodes, therefore, do not allow for a electrical field, which minimizes dispersion. (iv) The arrangement of two point electrodes at the in and out sections likewise proves to be no optimal means to reduce dispersion beyond the pressure-driven flow. Thus, meander geometries of channels, in general, cause severe problems if electroosmotic pumping needs to be achieved in combination with minimized dispersion.

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