Experimental Setup for Studying The Permeability of a Porous Medium in The Field of Elastic Vibrations

2021 ◽  
Author(s):  
E.A. Marfin ◽  
A.A. Abdrashitov ◽  
R.N. Gataullin
Keyword(s):  
Porous Medium ◽  
Experimental Setup ◽  
Elastic Vibrations

InterFrost Project Phase 2: Updated experiment results for the validation of Cryohydrogeological codes (Frozen Inclusion)

2020 ◽  
Author(s):  
Christophe Grenier ◽  
Francois Costard
Keyword(s):  
Porous Medium ◽  
Thermal State ◽  
Thermal Evolution ◽  
Initial Position ◽  
Second Phase ◽  
Test Cases ◽  
Experimental Setup ◽  
Experimental Conditions ◽  
Single Experiment ◽  
Implementation Phase

<p>Recent field and modelling studies indicate that a fully-coupled, multi-dimensional, thermo-hydraulic (TH) approach is required to accurately model the evolution of permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require validation. This issue was first addressed within the InterFrost IPA Action Group, by means of an intercomparison of thirteen numerical codes for two-dimensional TH test cases (TH2 & TH3). The main results (cf. Grenier et al. 2018 and wiki.lsce.ipsl.fr/interfrost) demonstrate that these codes provide robust results for the test cases considered.</p><p>The second phase of the InterFrost project is devoted to the simulation of a cold-room reference experiment based on test case TH2 (Frozen Inclusion). In a first implementation phase of the experimental setup, the initial frozen inclusion was inserted in the setup prior to the complete filling of the porous medium and the flow initiation. The thermal evolution of the system was monitored by thermistors located at the center of the initial inclusion and along the downgradient centerline. This setup provided optimal conditions to control the initial experiment geometries but resulted in slight differences in the initialization time for different experiments.</p><p>In a second implementation strategy, we now consider “in place” generation of an initial frozen inclusion through a cooling coil. The initial frozen inclusion is obtained after the initial cooling time and its initial thermal state is measured by means of an array of thermistors. In a second step, the flow is initiated, and the thermal evolution is monitored through an array of 11 thermistors (within the initial position and downgradient).</p><p>The experimental setup and an overview of all monitoring results as well as preliminary numerical simulations are presented. In an attempt to prevent formerly observed drifts in total water flowrates, the porous medium is renewed for each single experiment considering some key experimental conditions (full-flow vs. no-flow). A repetition of experiments provides an estimation of experimental uncertainty bounds. Derived results and conclusions from this experiment will form the basis for the next phase within the InterFrost validation exercise.</p>

Experimental Investigation of Wicking Flow Through a Porous Medium as a Validation Approach for Numerical Simulations

2013 ◽  
Author(s):  
Mahmoud Moeini Sedeh ◽  
J. M. Khodadadi
Keyword(s):  
Porous Medium ◽  
Pressure Gradient ◽  
Porous Structure ◽  
Numerical Simulations ◽  
Experimental Setup ◽  
Liquid Penetration ◽  
Foam Sample ◽  
Penetration Length ◽  
Flow Through ◽  
Graphite Foam

Wicking flow through a porous medium with nearly-spherical interconnected pores was investigated experimentally for validation of numerical simulations of multiphase flow through a porous structure. The experimental setup was designed to eliminate the effects of pressure gradient and gravity. The porous structure is a commercial graphite foam (PocoFoam® with an average pore size of 400 μm and porosity of 75%) and the penetrating liquid is cyclohexane. The penetration of the liquid into the foam sample is unidirectional. The liquid originates from a side reservoir toward an empty reservoir on the opposite side, with the porous sample between the reservoirs. The level of the liquid was kept constant on the fluid source side of the sample, i.e. in the reservoir full of liquid. Since the top side of the experimental setup is exposed to the ambient, there is no pressure gradient effect. Thus, penetration of the liquid occurs only as a result of interfacial effects (i.e. surface tension and contact angle) while pressure gradient and gravity play negligible roles. The instantaneous liquid penetration length (i.e. the average position of liquid interface) versus time was measured experimentally using video frame analysis of the tests recorded with a digital camera aligned with the experimental setup and observing from the top. The experiments were repeated several times to ensure their repeatability and the variations of the liquid interface position were obtained at different time instants. The results exhibit agreement with the theoretical Washburn equation for the liquid penetration length for horizontal wicking along cylindrical capillaries. Moreover, the possible causes of deviations from the Washburn equation were studied. Furthermore, the experimental results are in good agreement with numerical results of the liquid penetration through a series of pores. The numerical analysis was performed for a two-dimensional model that is based on the geometric features of the graphite foam sample and using the multiphase Volume-of-Fluid (VOF) method.

Modelling Of Transport And Capture Of Particles In A Porous Medium

2019 ◽  
pp. 56-60
Keyword(s):  
Porous Medium ◽  
Asymptotic Solution ◽  
Retention Mechanism ◽  
Inverse Filtering ◽  
Underground Structures ◽  
Loose Soil ◽  
Monodisperse Suspension ◽  
Homogeneous Porous Medium ◽  
Model Equations ◽  
Pass Through

The study of the transport and capture of particles moving in a fluid flow in a porous medium is an important problem of underground hydromechanics, which occurs when strengthening loose soil and creating watertight partitions for building tunnels and underground structures. A one-dimensional mathematical model of long-term deep filtration of a monodisperse suspension in a homogeneous porous medium with a dimensional particle retention mechanism is considered. It is assumed that the particles freely pass through large pores and get stuck at the inlet of small pores whose diameter is smaller than the particle size. The model takes into account the change in the permeability of the porous medium and the permissible flow through the pores with increasing concentration of retained particles. A new spatial variable obtained by a special coordinate transformation in model equations is small at any time at each point of the porous medium. A global asymptotic solution of the model equations is constructed by the method of series expansion in a small parameter. The asymptotics found is everywhere close to a numerical solution. Global asymptotic solution can be used to solve the inverse filtering problem and when planning laboratory experiments.

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