Irreversibilities in a triple diffusive flow in various porous cavities

2021 ◽  
Author(s):  
Zafar H. Khan ◽  
Waqar A. Khan ◽  
Mikhail A. Sheremet ◽  
Jiguo Tang ◽  
Licheng Sun
Keyword(s):  
Diffusive Flow

Computational models of filtration gas combustion

2017 ◽  
Vol 32 (2) ◽  
Author(s):  
Yuri M. Laevsky ◽  
Tatyana A. Nosova
Keyword(s):  
Heat Flow ◽  
Numerical Experiments ◽  
Computational Models ◽  
Two Dimensional ◽  
Multidimensional Model ◽  
Gas Combustion ◽  
Total Enthalpy ◽  
Diffusive Flow ◽  
Temperature Heat ◽  
The One

AbstractA multidimensional model of filtration gas combustion is presented. The model is based on the system of conservation laws of ‘temperature – heat flow’, ‘mass–diffusive flow’ types with introducing the concept of total enthalpy flow. Results of numerical experiments are presented for the one- and two-dimensional problems for different conditions and parameters.

Modeling of Before Closure Zero Slope Pressure Derivative in a Diagnostic Fracture Injection Test DFIT

2022 ◽  
Author(s):  
Guoqing Liu ◽  
Jie Wang ◽  
Christine Ehlig-Economides
Keyword(s):  
Interface Crack ◽  
Radial Flow ◽  
Fracture Propagation ◽  
Friction Loss ◽  
Open Crack ◽  
Large Magnitude ◽  
Injection Test ◽  
Layer Interface ◽  
Diffusive Flow ◽  
Tip Extension

Abstract Recent diagnostic fracture injection test (DFIT) data presented on a Bourdet log-log diagnostic plot showed derivative slope of 0 in the before closure (BC) portion of the DFIT response. Some works qualitatively describe it as radial flow. This behavior has not been quantitatively analyzed, modeled and matched. The present work disagrees with the hypothesis of radial flow and successfully matches the relatively flat trend in the Bourdet derivative with a model dominated by friction dissipation coupled with tip extension. The flat trend in Bourdet derivative occurs shortly after shut-in during the before closure period. Because a flat derivative trend suggests diffusive radial flow, our first approach was to consider the possibility that an open crack at a layer interface stopped the fracture propagation and caused the apparent radial flow behavior observed in falloff data. However, a model that coupled pressure falloff from diffusive flow into a layer interface crack with pressure falloff from closure of a fracture that propagated up to the layer interface failed to reproduce the observed response. Subsequently, we discovered that existing models could match the data without considering the layer interface crack. We found that data processing is very important to what is observed in derivative trends and can mislead the behavior diagnosis. We succeeded to match one field DFIT case showing an obvious early flat trend. The presence and dominance of geomechanics, coupled with diffusive flow, disqualify the description of the flat trend in Bourdet derivative as radial flow. Instead, flow friction coupled with tip extension can completely match the observed behavior. Based on our model, cases with a long flat trend have large magnitude near-wellbore tortuosity friction loss and relatively long tip extension distance. Further, we match the near wellbore tortuosity behavior with rate raised to a power lower than the usually assumed 0.5. The significance of these analyses relates to two key factors. First, large magnitude near wellbore tortuosity friction loss increases the pressure required for fracture propagation during pumping. Second, tip extension is a way to dissipate high pumping pressure when very low formation permeability impedes leakoff. Matching transient behavior subject to the presence of both of these factors requires lowering the near-wellbore tortuosity exponent.

Nanopore Protein Biosensor Using Diffusive Flow

2011 ◽  
Vol 50 ◽  
pp. 127002
Author(s):  
Jung-Yeul Jung ◽  
Trevor J. Thornton ◽  
Marcella Chiari ◽  
Tae-Hyoung Kim
Keyword(s):  
Diffusive Flow

scholarly journals Effect of chemical reaction and radiation on double diffusive flow of a viscous, dissipative fluid through porous medium in a rectangular cavity with heat sources

2013 ◽  
Vol 18 (4) ◽  
pp. 1115-1150
Author(s):  
T.L. Raju ◽  
P. Muralidhar
Keyword(s):  
Porous Medium ◽  
Stream Function ◽  
Rectangular Cavity ◽  
Heat Sources ◽  
Element Analysis ◽  
Coupled Equations ◽  
Stiffness Matrices ◽  
Diffusive Flow ◽  
Transfer Flow ◽  
And Diffusion

Abstract In this paper, an attempt is made to discuss the combined influence of radiation and dissipation on the convective heat and mass transfer flow of a viscous fluid through a porous medium in a rectangular cavity using the Darcy model. Making use of the incompressibility, the governing non-linear coupled equations for the momentum, energy and diffusion are derived in terms of the non-dimensional stream function, temperature and concentration. The Galerkin finite element analysis with linear triangular elements is used to obtain the global stiffness matrices for the values of stream function, temperature and concentration. These coupled matrices are solved using an iterative procedure and expressions for the stream function, temperature and concentration are obtained as linear combinations of the shape functions. The behavior of temperature, concentration, the Nusselt number and Sherwood number is discussed computationally for different values of the governing parameters, such as the Rayleigh Number (Ra), heat source parameter (α), Eckert number (Ec), Schmidt Number (Sc), Soret parameter (S0), buoyancy ratio (N).

Exact solution of the Linear Parabolic Approximation for flow-depth based diffusive flow routing

2018 ◽  
Vol 563 ◽  
pp. 620-632 ◽  
Author(s):  
Luigi Cimorelli ◽  
Luca Cozzolino ◽  
Andrea D'Aniello ◽  
Domenico Pianese
Keyword(s):  
Exact Solution ◽  
Flow Depth ◽  
Parabolic Approximation ◽  
Flow Routing ◽  
Diffusive Flow

Diffusive Flow

2015 ◽  
pp. 1-3
Author(s):  
Boguslaw Kruczek
Keyword(s):  
Diffusive Flow

Hydrophilic solute transport across rat alveolar epithelium

1989 ◽  
Vol 66 (5) ◽  
pp. 2320-2327 ◽  
Author(s):  
M. M. Berg ◽  
K. J. Kim ◽  
R. L. Lubman ◽  
E. D. Crandall
Keyword(s):  
Water Flow ◽  
Alveolar Epithelium ◽  
Lavage Fluid ◽  
Alveolar Space ◽  
Apparent Permeability ◽  
Diffusive Flow ◽  
Permeability Surface ◽  
Small Pore ◽  
Pore Area ◽  
Flow Through

Diffusional fluxes of a series of hydrophilic nonelectrolytes (molecular radii ranging from 0.15 to 0.57 nm) were measured across the alveolocapillary barrier in the isolated perfused fluid-filled rat lung. Radiolabeled solutes were lavaged into the distal air spaces of isolated Ringer-perfused lungs, and apparent permeability-surface area products were calculated from the rates of isotope appearance in the recirculating perfusate. These data were used to estimate theoretical equivalent pore radii in the alveolar epithelium, with the assumption of diffusive flow through water-filled cylindrical pores. The alveolar epithelium is best characterized by two pore populations, with small pores (radius 0.5 nm) occupying 98.7% of total pore area and larger pores (radius 3.4 nm) occupying 1.3% of total pore area. Net water flow out of the alveolar space was measured by including an impermeant solute (dextran) in the lavage fluid and measuring its concentration in the alveolar space as a function of time. Under control conditions, net water flow averaged 167 nl/s. When 24 microM terbutaline was added to the perfusate, net water flow increased significantly to 350 nl/s (P less than 0.001). Terbutaline had no effect on the fluxes of either glycerol (which traverses the small pore pathway) or sucrose (which traverses the large pore pathway). These findings indicate that the intact mammalian alveolar epithelium is complex and highly resistant to the flow of solutes and water.

A Molecular Dynamics Study of Soaking During Enhanced Oil Recovery in Shale Organic Pores

SPE Journal ◽  
2020 ◽  
Vol 25 (02) ◽  
pp. 832-841 ◽  
Author(s):  
Felipe Perez ◽  
Deepak Devegowda
Keyword(s):  
Molecular Dynamics ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Volatile Oil ◽  
Pore Network ◽  
Fluid Mixture ◽  
Soaking Time ◽  
Diffusive Flow ◽  
Dynamics Simulations

Summary In this work we use molecular dynamics simulations to investigate the interactions during soaking time between an organic solvent (pure ethane) initially in a microfracture and a mixture of hydrocarbons representative of a volatile oil, and other reservoir fluids such as carbon dioxide and water, originally saturating an organic pore network with a predominant pore size of 2.5 nm. We present evidence of the in-situ fractionation in liquid-rich shales and its implications in enhanced oil recovery (EOR) projects. We also discuss the behavior of the larger and heavier molecules in the fluid mixture while the solvent interacts with them. Notably, prior to solvent invasion of the pores and further mixing with the reservoir fluids, the heavier hydrocarbons in the mixture are initially adsorbed onto the pore surface and pore throats surface, partially clogging them. We show that the porous structure of kerogen and the presence of adsorbed molecules of asphaltenes and resins in the pore throats act as a molecular sieve and may be one of the reasons for the fractionation of the reservoir fluids. The differing ability of the solvent to desorb and mix with different hydrocarbon species is another reason for the fractionation occurring during soaking. Our simulations show that the production of reservoir fluids occurs due to a countercurrent diffusive flow from the organic pore network to the microfracture driven by the concentration gradient between the two regions.

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