Abstract The effect is studied of capillarity‐driven viscous flow through macroscopic liquid films during the isothermal drying porous materials. A mathematical model that accounts for in a 2‐D pore network, both and bulk phase, presented. results are compared with previous works do not account experimental findings by other authors. It shown film major transport mechanism materials, its being dominant when capillarity controls process, which case typical applications. By contrast,...

In a recent paper [Yiotis et al., Phys. Rev. E 85, 046308 (2012)] we developed model for the drying of porous media in presence gravity. It incorporated effects corner film flow, internal and external mass transfer, effect Analytical results were derived when gravity opposes hence leads to stable percolation front. this paper, test theory using laboratory experiments. A series isothermal experiments glass bead packings saturated with volatile hydrocarbons is conducted. The transparent cells...

We study the effects of liquid films on isothermal drying porous media. They are important for transport to an evaporation interface, far from receding clusters. Through a transformation, problem is mapped Laplace equation around percolation From its solution, properties obtained in terms capillary number. Consistent with experimental evidence, film flow shown accelerate significantly.

We present a pore‐network model for drying processes in porous media that couples convective‐diffusive mass transfer over the external surface of medium with transport mechanisms within material, namely, flow through liquid films form at pore walls and diffusion vapors dry pores. study effects boundary layer thickness, film‐based capillary number, Peclet number purge gas flows on shape curves overall recovery times. show rate remains practically constant, as long span across entire network...

We perform a numerical and experimental study of immiscible two-phase flows within predominantly 2D transparent PDMS microfluidic domains with disordered pillar-like obstacles, that effectively serve as artificial porous structures. Using high sensitivity pressure sensor at the flow inlet, we capture experimentally dynamics under fixed rate conditions fluid-fluid interface advances domain, while also monitoring corresponding phase distribution patterns using optical microscopy. Our covers 4...

The improvement of dielectric and thermal properties insulating oils used in High Voltage (HV) equipment has been a key part research over the last three decades. In this study, natural ester oil is as matrix dispersions two semi-conducting nanoparticles (NPs), titanium oxide (TiO₂) silicon carbide (SiC), are prepared 0.004 weight percentage ratio (0.004% w/w). terms features, diffusivity conductivity measured large temperature range between 25 90 °C. By means properties,...

This study is focused on exploring the change in dielectric and cooling efficiency of vegetable oil following integration semiconducting SiC TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles two different weight percentages by comparing corresponding behavior nanofluids at time their synthesis after one month ageing. The thermal response has been evaluated means diffusivity conductivity, while properties are measured with...

In the present study we examine thermodynamic consistency of lattice Boltzmann equation (LBE) models that are based on forcing method by comparing different numerical treatments LBE for van der Waals fluids. The applied calculation bulk and interfacial properties at various temperatures. effect interface density gradient parameter, kappa , controls surface tension, is related explicitly with fluid characteristics, including temperature, molecular diameter, spacing, through employment a...

We study the dynamics of nonwetting liquid blobs during immiscible two-phase flows in stochastically reconstructed porous domains predominantly saturated by a wetting fluid. The flow problem is solved explicitly using Lattice-Boltzmann model that captures both bulk phase and interfacial process. show undergo continuous life cycle dynamic breaking up coalescence producing two populations blobs, mobile stranded one, exchange continuously mass between them. process reaches ``steady state'' when...

We develop a mathematical model for the drying of porous media in presence gravity. The incorporates effects corner flow through macroscopic liquid films that form cavities pore walls, mass transfer by diffusion dry regions medium, external over surface, and effect consider two different cases: when gravity opposes leads to stable percolation front, it acts opposite direction. In this part, we analytical results problem can be cast as an equivalent continuum described one-dimensional (1D)...

Abstract We study experimentally the flow of non-wetting ganglia during co-injection n -heptane and water in a predominantly 2D PMMA micromodel, which is constructed based on stochastic digital algorithm. The dynamics phase distribution patterns are recorded optically post-processed using cluster identification motion tracking algorithms order to characteristics interactions between mobile stranded populations. focus primarily effects capillary number (Ca) ratio injection rates ( Q )...

We perform two-dimensional pore network simulations of isothermal drying in order to provide better insight on the structure patterns, particularly frontal region, both presence and absence gravity forces. Our numerical results for fractal dimension invading gaseous phase (D p = 1.88 ± 0.03) front perimeter e 1.34 0.06) are very good agreement with reported experimental theoretical values. The scaling width, σ f , a front-stabilizing gradient is also examined it found scale Bond number...

We investigate experimentally the sweeping of a nonwetting fluid by wetting one in quasi-two-dimensional porous medium consisting random obstacles. focus primarily on resulting phase distributions and residual saturation as function normalized flow rate-the capillary number Ca-at steady state. The liquid is then flowing partially saturated immobile blobs. decrease an irreversible process that depends strongly history more specifically highest value Ca reached past. At lower values, when...

Development of ``tortuous'' mean ganglia flux paths during immiscible two-phase flow through a disordered and periodic 2D porous domain is studied. Results reveal that such are related to the gradual mobilization stranded due pore-scale interplay between capillary, gravity, viscous forces.

Abstract We propose an integrated methodology for the design and fabrication of 3D micromodels that are suitable pore-scale study transport processes in macroporous materials. The micromodels, bear characteristics sandstone, such as porosity, mean pore size, etc, designed following a stochastic reconstruction algorithm allows fine-tuning porosity correlation length spatial distribution solid material. then construct series at very fine resolution (i.e. $$16\,\upmu $$ <mml:math...