Data Processing in Moving Boundary Problems of One-Dimensional Non-Darcy Flow in Semi-Infinite Porous Media

2014 ◽  
Vol 977 ◽  
pp. 515-519
Author(s):  
Rong Rong Jin ◽  
Jia Hang Wang
Keyword(s):  
Porous Media ◽  
Mathematical Models ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Moving Boundary ◽  
Constant Flow ◽  
Production Time ◽  
Rate Condition ◽  
Exact Analytical Solutions ◽  
Constant Flow Rate

The paper establishes dimensionless mathematical models of the fluid flow in semi-infinite porous media with constant flow rate. Exact analytical solutions of these dimensionless mathematical models are derived by new definitions of dimensionless variables and Laplace transformation. Comparison curves of dimensionless moving boundary under different values of dimensionless Threshold Pressure Gradient (TPG) are plotted from newly proposed exact analytical solutions. An example is used to demonstrate pressure distribution in different positions with different TPG. It is shown that for the constant flow rate condition, the moving boundary extends to infinite in porous media with increasing production time. Steeper pressure curve is observed in larger TPG, which also exhibits greater pressure drop gradient and shorter pressure propagation distance at the same production time.

On elastic regime of filtration in hydraulic fracture

2016 ◽  
Vol 11 (2) ◽  
pp. 156-166
Author(s):  
V.Sh. Shagapov ◽  
Z.M. Nagaeva
Keyword(s):  
Pressure Drop ◽  
Rheological Properties ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Hydraulic Fracture ◽  
Constant Pressure ◽  
Constant Flow ◽  
Exact Analytical Solutions ◽  
Constant Flow Rate ◽  
Pressure Evolution

Fluid recovery from a well in the modes of constant pressure drop and constant flow rate is considered basing on a theoretical model of filtration in a hydraulic fracture. Exact analytical solutions are obtained that allowed analyzing the effect of the reservoir and fracture properties (such as porosity, permeability and crack width) as well as the rheological properties of the saturating fluid upon: pressure evolution in the fracture, well flow rate at constant pressure drop, and pressure evolution in the wellbore. On the basis of theoretical models describing the filtration for a crack in an oil or gas reservoirs, the considered problem on the selection of fluids from the well in modes constant differential pressure and constant flow. For the considered tasks are received exact analytical solutions, based on which we analyzed the influence of reservoir characteristics of the formation and fractures (for example, their porosity, permeability and width of cracks) and the rheological properties of the saturating fluid on the evolution of the pressure in the fracture, the production rate at a constant differential to the dynamics of the pressure in the well.

Applied Mechanics in Moving Boundary Problems of One-Dimensional Non-Darcy Flow in Semi-Infinite Long Porous Media

2014 ◽  
Vol 977 ◽  
pp. 399-403
Author(s):  
Jia Hang Wang ◽  
Lei Wang ◽  
Duo Kai Zhou
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Mathematical Models ◽  
Analytical Solutions ◽  
Moving Boundary ◽  
Boundary Problems ◽  
Threshold Pressure Gradient ◽  
Depression Cone ◽  
Boundary Distance ◽  
Pressure Propagation

Dimensionless mathematical models of the fluid flow in the semi-infinite long porous media with constant production pressure on the inner boundary conditions are built, which include the effect of threshold pressure gradient (TPG). The analytical solutions of these dimensionless mathematical models are derived through new definitions of dimensionless variables. Comparison curves of the dimensionless moving boundary under different values of dimensionless TPG are plotted from the proposed analytical solutions. For the case of constant production pressure, a maximum moving boundary exists, beyond which the fluid flow will not occur. The value of maximum boundary distance decreases with increasing TPG. However, the velocity of pressure propagation decreases with time. The larger the TPG is, the steeper the curve of pressure depression cone is and the shorter the distance of the pressure propagation is.

scholarly journals Pore-Scale Simulations of Particles Migration and Deposition in Porous Media Using LBM-DEM Coupling Method

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 465
Author(s):  
Yanjie Zhou ◽  
Liping Chen ◽  
Yanfeng Gong ◽  
Shilin Wang
Keyword(s):  
Porous Media ◽  
Critical Velocity ◽  
Flow Rate ◽  
Shear Force ◽  
Particle Deposition ◽  
Moving Boundary ◽  
Low Flow ◽  
Rate Condition ◽  
Groundwater Source ◽  
Low Flow Rate

This paper studies the migration and deposition of suspended particles in porous media. This problem results from the fact that during the operation of a groundwater source heat pump, the recharging process will contribute to the impairment of soil permeability. A coupling lattice Boltzmann method, discrete element method and immersed moving boundary method were used to investigate the migration of particles in porous media. The DKT (Drifting, Kissing, Tumbling) phenomena were employed to validate our program. The coupled effects of concentration, flow rate and pH on the clogging mechanism of the porous media were analyzed. Results show that, due to the repulsive barrier between the particles and porous media, there is a critical velocity. At a low flow rate, the deposition ratio increases with the increase in velocity. Beyond the critical velocity, the deposition ratio decreases when the velocity increases due to higher shear force. Permeability impairment increases with the increase in concentration, especially in the low flow rate condition. Changes in pH mainly affect the repulsive barrier. For a low flow rate, the decrease in repulsive barrier greatly promotes the deposition of particles. Under the condition of favorable deposition, the increase in flow rate reduces the deposition phenomenon. Under the condition of unfavorable deposition, the lower flow rate condition has a lower deposition ratio. The process of particle deposition and the dynamic motion after deposition were observed such as particles gliding over the surface. Accumulated particles in the downstream form bridges and hinder fluid flow. At a high flow rate, strong shear force is more capable of destroying bridges and recovering permeability. Adsorbed particles glide on the surface of the grain and deposit in the downstream. This paper aims to help understanding of the micro-events of particle deposition and the clogging process.

The Simulation of the Un-Saturated Flow in the Dual-Scale Porous Media under Constant Flow Rate

2013 ◽  
Vol 753-755 ◽  
pp. 2747-2751
Author(s):  
Xin Ye ◽  
Shi Lin Yan
Keyword(s):  
Porous Media ◽  
Flow Rate ◽  
Constant Flow ◽  
Filling Process ◽  
Saturated Flow ◽  
Constant Flow Rate ◽  
Single Scale ◽  
Pore Flow ◽  
Dual Scale

Considering the un-saturated in the experiment, the purpose of this paper is achieving a simple 1d molds unsaturated simulation of the filling process through the compiled software pore-flow and compare the single-scale result with the dual-scale result.

Pumpless Fuel Supply Using Pressurized Fuel Regulated by Autonomous Flow-Rate Regulation Valves

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Il Doh ◽  
Young-Ho Cho
Keyword(s):  
Fuel Cells ◽  
Flow Rate ◽  
Electrical Power ◽  
Initial Pressure ◽  
Flow Regulation ◽  
Present System ◽  
Constant Flow ◽  
Constant Flow Rate ◽  
Fuel Supply ◽  
Fuel Flow

A pumpless fuel supply using pressurized fuel with autonomous flow regulation valves is presented. Since micropumps and their control circuitry consume a portion of the electrical power generated in fuel cells, fuel supply without micropumps makes it possible to provide more efficient and inexpensive fuel cells than conventional ones. The flow regulation valves in the present system maintain the constant fuel flow rate from the pressurized fuel chamber even though the fuel pressure decreases. They autonomously adjust fluidic resistance of the channel according to fuel pressure so as to maintain constant flow rate. Compared to previous pumpless fuel supply methods, the present method offers more uniform fuel flow without any fluctuation using a simple structure. The prototypes were fabricated by a polymer micromolding process. In the experimental study using the pressurized deionized water, prototypes with pressure regulation valves showed constant flow rate of 5.38 ± 0.52 μl/s over 80 min and 5.89 ± 0.62 μl/s over 134 min, for the initial pressure in the fuel chamber of 50 and 100 kPa, respectively, while the other prototypes having the same fluidic geometry without flow regulation valves showed higher and gradually decreasing flow rate. The present pumpless fuel supply method providing constant flow rate with autonomous valve operation will be beneficial for the development of next-generation fuel cells.

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