Relaxation Time Lattice Boltzmann Method Research Articles

Numerical simulation of combined effects of a vertical magnetic field and thermal radiation on natural convection of non-Newtonian fluids confined between circular and square concentric cylinders

BackgroundThis study addresses magnetohydrodynamic (MHD) natural convection involving non-Newtonian fluids. Focusing on the annular region between concentric circular and square cylinders, the research examines the impact of a vertical magnetic field and thermal radiation. MethodsThe Multiple Relaxation Time Lattice Boltzmann Method (MRT-LBM) is employed to simulate momentum and energy interactions in non-Newtonian fluid. Control parameters like Rayleigh number, Hartmann number, Radiation parameter, aspect ratio, square cylinder subdivision, and power-law index are systematically varied, while maintaining a constant Prandtl number. Significant findingsUsing shear-thinning fluid (n < 1) significantly improves cooling, particularly in conjunction with radiation effect. Correlations for the mean Nusselt number are established, offering insights. Results emphasize the substantial influence of parameters like Ra, Rd, and AR. High values of the latter promote the flow intensity and heat evacuation. For n < 1, increasing Ra from 103 to 5 × 104 results in a substantial increase in the heat transfer rate reaching 65 %. For shear-thickening fluid, the heat transfer rate is reduced by 25.31 % at Ra = 5 × 104 when Ha is increased from 0 to 50 in the absence of radiation. In addition, radiation enhances the heat transfer rate by 71.41 % by incrementing Rd from 0 to 0.8 for Ha = 0. The most pronounced effect of the radiation parameter is observed in the cases of Newtonian and shear-thickening fluids. Conversely, Ha and n act by reduction effects on the outputs of the problem. The attenuating effect of the magnetic field is more pronounced in the case of shear-thinning fluids. The plot of mean Nusselt number vs. AR shows an hysteresis phenomenon due to the existence of multiple steady solutions in a range of this parameter. In the latter range of AR, heat transfer induced by multicellular flow is higher than that induced by bicellular one. Heat transfer is somewhat enhanced by the RC configuration, compared to SC one.

Study on the flow structure in curved open channels with suspended vegetation using multi relaxation time lattice Boltzmann method

Study on the flow structure in curved open channels with suspended vegetation using multi relaxation time lattice Boltzmann method

Lattice Boltzmann simulations of quasi-steady film and axisymmetric nucleate boiling

An axisymmetric multiple relaxation time lattice Boltzmann method utilizing the Shan-Chen pseudo-potential model is developed and combined with an axisymmetric finite difference approximation of the energy equation to form a hybrid method with a view toward studying axisymmetric nucleate boiling. The mechanism of phase change in the Shan–Chen model is investigated, and the model is validated by simulating a Stefan problem as well as simulations of quasi-steady film boiling with comparisons to established results. Axisymmetric quasi-steady nucleate boiling is then investigated including examining the effect of the wetting properties of surfaces by varying the wettability force to vary the dynamic contact angle.

Numerical investigation of flow past a triangular cylinder at various Reynolds numbers

Numerical simulation of flow around a triangular cylinder placed both in left and right position at Reynolds number Re = 80–200 is presented in this study. The single relaxation time lattice Boltzmann method is used. The results are obtained in terms of vorticity contour visualization, drag and lift coefficients, and force statistics. Regular vortex shedding is observed for both cases, but the vortices generated for a triangular cylinder placed in the right position move toward the top downstream position as the range of Reynolds number increases due to effect of pressure (effect of thrust). The drag coefficient is constant, and lift coefficient is containing negative values from Re = 80–150 for that case, but negative Cdmean values are not observed for a triangular cylinder placed in the left position. In that case, it is due to the reason that the effect of thrust diminishes. The maximum value of Cdmean is obtained at Re = 200, that is, 1.5006 for the left triangular cylinder, but the value of the mean drag coefficient for the right triangular cylinder is zero throughout the cases for Re = 80–200. No fluid forces are produced for right triangular case. The Strouhal number (St) values increased by increasing the Reynolds number, i.e., Re = 80–200, for the right triangular cylinder, and it has a mixed trend for the left triangular cylinder. In literature, a lot of work has been found on rectangular and square cylinders, but triangular cylinder has not been studied much.

Solving 2D damped Kuramoto-Sivashinsky with multiple relaxation time lattice Boltzmann method

Lattice Boltzmann method (LBM) is a powerful fluid flow solver. Using this method to solve other PDEs might be a difficult task. The first challenge is to find a suitable local equilibrium distribution function (EDF) capable of recovering the desired PDE. The next difficulty arises from the explicit nature of LBM. The conditional stability of the LBM algorithm affects the numerical solution accuracy. Damped Kuramoto–Sivashinsky (DKS) equation is a fourth–order PDE that recently challenged many numerical methods' abilities. This equation is highly sensitive to a parameter that causes three states of solutions in a small interval of freedom. In this paper, we challenged LBM to solve the two–dimensional DKS equation by finding EDF using the Chapman–Enskog analysis up to the fourth–order. Also, the von Neumann analysis and a simple genetic algorithm are applied to find reliable values for the free parameters. Furthermore, a modification on image-based ghost node method is proposed for implementation of the boundary conditions in the complex geometries.

Analysis of Fluid Flows in Bounded Domain with Particular Shape of a Cavity using Lattice Boltzmann Method

Background: The present work numerically models the incompressible, continuous phase, viscous flow of Newtonian fluid flow in a bounded domain of two-dimensional cavity that is driven by walls and contains grooves in the shape of squares on the lower wall. With the help of the mesoscopic lattice Boltzmann method (LBM) and D2Q9 square lattice model, simulation results are found stable and reliable. The flow physics of the problem by varying Reynolds number, the height and quantity of lower wall grooves, and other fluid flow characteristics within the bounded domain are studied in detail. It is seen that the effects of the groove heights and wavelengths on the fluid flow are structured within the bounded domain. The study is performed from low Re = 100 to high Re = 3200, with minimum two and maximum four-wavelength grooves evaluated on the bottom surface, each having a height of low 0.25 and high 0.75. Additionally, a thorough discussion of complicated vortex dynamics is provided regarding the input parameters and geometry. Objective: The current study aims to use mesoscopic LBM to analyze incompressible viscous fluid flows on complex geometries other than rectangular shapes. Methods: Mesoscopic approach of kinetic theory-based Lattice Boltzmann method (LBM) is implemented in the current work. The popular Single Relaxation Time Lattice Boltzmann method with D2Q9 square lattice model and second-order accurate boundary condition is adopted for the current study. Results: The numerical approach of LBM is used to simulate fluid flows in a 2D bounded domain with grooved bottom surfaces. The influence of different factors, such as the height of bottom-wall surface grooves, flow Reynolds number, and wavelength of these grooves on flow patterns, is then investigated. Conclusion: The numerical study of the bounded domain is considered, and the Reynolds number is varied from 100 to 3200, with two and four-wavelength grooves evaluated on the bottom surface, each having a height of 0.25 and 0.75. The impacts on the flow pattern both within and slightly above the grooves of the computational findings for different Reynolds numbers, groove heights, and groove wavelengths are evaluated. As the Reynolds number rises, the mixing phenomenon of fluid is shown to flow more quickly in the wall-driven enclosures.

Numerical simulation on mixed convection in U-shaped lid-driven cavity with non-uniform temperature on sidewalls using multi relaxation time lattice Boltzmann method

In the present work, we numerically investigated the mixed convection in a U-shaped lid-driven cavity with non-uniformly heated sidewalls by using the MRT-LBM technique to stimulate the flow behavior and temperature fields. Both vertical walls (Left and Right) are non-uniformly heated, and the top horizontal wall is kept at adiabatic and moving with constant velocity u0. The bottom U-shaped wall is kept at constant temperature. The results are presented for different parameters such as Richardson number (0.01−100), Prandtl number (0.7,1,7), aspect ratio of geometry (0.1,0.3,0.5,0.7,0.9), Grashof number (103,105,106,4 ×104,9 ×104). Nusselt number is also calculated along the heated wall. Our results demonstrate that the heat transfer rate at non-uniformly heated walls increases with an increase in the aspect ratio.

Micro-flow investigation on laying process in Al2O3 stereolithography forming

When printing Al2O3 parts by stereolithography technology, the laying process is an extremely important part. In the current work, the referred flow analysis was numerically investigated. The rheological behavior was measured to determine the rheological type of the slurry. According to the fitting analysis, a Sisko model was available to describe the non-Newtonian behavior. Then, the modified multiple relaxation time lattice Boltzmann method was proposed and validated to effectively improve the stability of the simulation. Based on the proposed method, the situations without and with printed solids in the previous layer were investigated by a series of simulations. The laying velocity and layer thickness were considered as two important factors on the laying process. When the situation without printed solids in the previous layer is analyzed, the streamlines and flow velocities curves were almost horizontal. With different laying velocities, the flow velocities show obvious differences at the same thickness. With different layer thicknesses, the difference is mainly embodied in the vertical velocity component. When the printed solid is considered, the solid seriously affected the smooth flow. The vortices appeared near the printed solid, which also caused the disturbance in both horizontal and vertical velocity components. The mentioned interfering factors indicated different actions on the flow. The research will contribute to understanding the flow of the laying process. It can help to select suitable laying velocity and layer thickness to avoid severe flow velocity fluctuation and redundant vertical velocity components.

Investigation of non-Newtonian power-law free convection affected by a magnetic field in an inclined quarter-circle chamber containing the lozenge-shaped obstacle via MRT-LBM of first and second laws of thermodynamics

Investigating the effect of the strength, type and angle of the magnetic field applied on the amount of entropy generation caused by the heat transfer of non-Newtonian fluid under the inflyence of heat production/absorption is the aim of the available study. The simulation has been done by writing the FORTRAN code using Multi relaxation time lattice Boltzmann method. Qualitative and quantitative comparison of the present work with preceding valid researches confirmed the accurateness of the outcomes. The magnetic field influence can be controlled by the angle of rotation of the chamber, and this impact decreases with power-law index enhancement. In general, application of a non-uniform magnetic field increases the mean Nusselt number by about 10% and leads to an increase in flow strength. The outcomes reveal that the impact of the angle of inclination chamber, type and direction of magnetic field application for dilatant fluid is insignificant. Increasing the coefficient of the heat absorption/production lessens the mean Nusselt number but increases the impact of the magnetic field. Enhancement of the barrier temperature and decreasing index of power-law results in an increment in the share of entropy generated by the magnetic field.

Accuracy improvement of immersed boundary-lattice Boltzmann and finite element method by iterative velocity correction

In an analysis of the fluid–structure interaction (FSI) problem, the non-slip boundary condition at solid walls cannot be accurately satisfied by the conventional immersed boundary-lattice Boltzmann coupling schemes due to insufficient interpolation accuracy. To solve this problem, an improved iterative velocity correction procedure for the immersed boundary-lattice Boltzmann coupling scheme is proposed by introducing a modified velocity operator. The particle distribution function was modified at each time step, and the evolution governing equation of the multiple relaxation time-lattice Boltzmann method was performed. A numerical framework for coupling lattice Boltzmann and finite element methods for transient problems involving FSI was established, and the iterative velocity correction immersed boundary method was used for the partitioned approach. The solid structure was discretized with the finite element method, while the single-component fluid flows were simulated with the lattice Boltzmann method. An FSI benchmark model was employed to verify the efficiency of the proposed coupling method. The results show that the developed method guarantees the non-slip boundary condition and maintains the convergence rate of the conventional immersed boundary method. In viscous flow and strong shearing flow, the accuracy of both stationary and moving solid boundaries is obviously improved.

Numerical Investigation of Convective Heat Transfer and Fluid Flow Past a Three Square Cylinders Controlled by a Partition in Channel

This document presents a research article on the control of fluid flow around three heated square cylinders placed side by side in a 2D horizontal channel using a flat plate. The objective of this research is to examine the effect of the position, length and height of a flat plate on fluid flow and heat transfer. For this purpose, numerical simulations are performed by using the Boltzmann double relaxation time multiple network method (DMRT-LBM). The MRT-D2Q9 and MRT-D2Q5 models are used to treat the flow and temperature fields respectively. In contrast to several existing investigations in the literature in this domain which study the passive control of the flow using a horizontal or vertical plate around a single cylinder, this work presents a numerical study on the effect of the position, length and height of a flat plate (horizontal and vertical) on three heated square cylinders on the flow and temperature fields. First, the effect of the position and length of the horizontal flat plate is examined. This study shows that the implementation of a flat plate of length Lp = 4D at a position g=3 behind the central cylinder reduces the amplitude of the Von Karman Street and allows large and regular heat exchange. Thus, in the second part, the effect of the position and height of the vertical flat plate is studied. The results obtained show that the implementation of a flat plate of height h=2D at a position g=3 behind the central cylinder improves the thermal exchange between the incoming fluid and the heated cylinders. This numerical work could lead to the prediction of the cooling of the electronic components: The cooling of the obstacles is all the better when the control plate is arranged at g = 3 and its height h = 2D in the case of the vertical plate or its length Lp equal to 4D in the case where the plate is implemented horizontally

CO2-oil diffusion, adsorption and miscible flow in nanoporous media from pore-scale perspectives

Enhancing shale/tight oil and sequestering CO2 by CO2 huff-n-puff have gained extensive attentions in recent years. However, the fundamental understanding of CO2-oil diffusion, competitive adsorption and miscible flow behaviors are mainly limited to the single pore scale based on molecular dynamics (MD) simulations, and that in nanoporous media are still ambiguous. In this work, we propose a novel multiple relaxation time lattice Boltzmann method (MRT-LBM) to simulate CO2-oil diffusion, adsorption and miscible flow in pore-scale nanoporous media, which is successfully verified by the Fick’s second law and MD simulations. The proposed model can obtain various fluid-surface molecular interaction forces (adsorption capacities) of CO2/oil single phase and CO2-oil miscible phase, and quantify the attraction and repulsion from the pore surface to CO2 and oil. Then, the effects of CO2 and oil phase heterogeneous adsorption capacity on CO2 diffusion, storage and oil extraction are quantitatively analyzed. Additionally, based on the MD simulations, we also study the adsorption and flow behaviors of CO2-nC8 miscible adsorption and flow behaviors in calcite nanoporous media. The results show that CO2 can diffuse into the oil phase in porous media more readily from the regions that are relatively attractive to CO2 and repulsive to oil. In porous media with heterogeneous adsorption capacity, CO2 first contacts with the CO2-friendly surface which is attractive to CO2 during diffusion, beneficial to CO2 storage. With an increasing nC8 mass percentage (OMP), the proportion of adsorbed CO2 increases, and that of free CO2 decreases. That indicates that the CO2 diffusing into the oil phase is firstly adsorbed on the surface. When CO2 adsorption reaches saturation, the density of CO2 in the bulk phase begins to increase. We also observed a critical OMP equaling 81% below which CO2 can enhance nC8 flow while having a negligible enhanced impact on nC8 flow beyond 81%. Additionally, with an increasing porous media size, the proportion of adsorbed CO2 decreases, and the critical OMP increases.

Investigation of Obstacles with Interactive Elements on the Flow in SiC Three-Dimensional Printing.

A single screw extruder is used in this study to efficiently transport SiC slurry in direct ink writing (DIW) technology. The deposits caused by low viscosity and the agglomerations resulting from the nonuniform mixing form the obstacles in the channel, which affect the normal flow of the slurry, theoretical outlet velocity, and interaction with other printing parameters. Therefore, it is necessary to study the effect mechanism of the obstacles on the flow. The obstacles are always irregular, which makes it difficult to directly analyze them. Irregular geometries are always composed of linear and/or arcuate elements; therefore, the obstacles can be simplified into regular geometries. In the present work, interactive elements, including line-line, line-arc, arc-arc situations are analyzed. Then, an improved multiple relaxation time lattice Boltzmann method (MRT LBM) with a pseudo external force is proposed for the flow analysis. The improved MRT LBM is combined with rheological test data to investigate cases with interactive elements, and the results are applied to reveal the general mechanism. The results show that the positions are common influencing factors, which affect the streamlines, outflow directions, and outlet velocity distributions. In addition, in different situations, different factors are considered to affect SiC slurry flow. It is obvious that the existed obstacles inevitably change the theoretical flow direction and outlet velocity, which has a synergistic effect on the printing parameters. It is necessary to understand the effect mechanism of the obstacles on the flow.

Natural convection heat transfer with anisotropic thermal diffusion for tilted two-dimensional cavities

The effects of a domain tilt (counterclockwise, γ=00,300and600) and an anisotropic thermal diffusion on the natural convection heat transfer inside a square or rectangular cavity are investigated. The multiple relaxation time Lattice Boltzmann method with a double distribution function is used. The simulations are performed for a range of Rayleigh number (Ra=104to108). It is observed that the number of eddies is reduced due to the counterclockwise inclination of the cavity for a given Rayleigh number. The flow reversal is observed with a change in γ and anisotropic thermal diffusion ratio (β). Further, the stretching and merging of the inner core eddy with changes in γ and β are discussed. The spatially averaged Nusselt number along the hot wall (Nu¯h) is calculated to study the heat transfer rate and characteristics. It shows that the rate of heat transfer increases with an increase in the inclination and the thermal diffusivity ratio. For Ra=107and108 the observed flow structures are unsteady. The heat transfer in this type of unsteady flow and corresponding thermal plume dynamics are studied by computing Nu¯h at each non-dimensional timestep.

LBM simulation of non-Newtonian fluid seepage based on fractional-derivative constitutive model

This paper proposes a truncated fractional-derivative constitutive model to consider the non-locality of non-Newtonian fluids. The single relaxation time lattice Boltzmann method (SRT-LBM) is used to simulate seepage of non-Newtonian fluid. The results are verified by analytical solutions while the flow characteristics of non-Newtonian fluids are explored. In the case of laminar flow, the steady-state velocity distribution of shear-thinning and shear-thickening fluids after 105 - time steps are compared with the analytical distribution, and the results show an agreement within 2%. For non-Newtonian index simulation, the thicker the fluid, the larger the velocity and the more volatility, implying the more complex flow characteristics for shear-thickening fluid. Additionally, small fractional indexes correspond to large computational errors in regions away from the boundary. Flow characteristics research shows that the seepage of power-law fluid in fractured media exhibits non-Darcy phenomenon. As the fractional index decreases (i.e., fluid becomes thicker), the obstruction of the medium increases, resulting in a reduction in the medium's permeability. The shear stress of non-Newtonian fluids can be memorized by the mean section velocity distribution, and the memory capacity of different fluids can be captured by the fractional index. Furthermore, the fractional-derivative critical Reynolds number is introduced to clarify the applicable conditions of non-Newtonian flow equations, which increase with diameter and initial kinematic viscosity. The fractional-derivative critical Reynolds number of dilatant fluids is larger than pseudoplastic fluids, due to the memory properties of the fluid as well as the physical characteristics.

On Numerical Modeling of Thermal Performance Enhancementof a Heat Thermal Energy Storage System Using a Phase Change Material and a Porous Foam

In this investigation, a comprehensive numerical analysis of the flow involved in an open-ended straight channel fully filled with a porous metal foam saturated and a phase change material (paraffin) has been performed using a single relaxation time lattice Boltzmann method (SRT-LBM) at the representative elementary volume (REV) scale. The enthalpy-based approach with three density functions has been employed to cope with the governing equations under the local thermal non-equilibrium (LTNE) condition. The in-house code has been validated through a comparison with a previous case in literature. The pore per inch density (10≤PPI≤60) and porosity (0.7≤ε≤0.9) effects of the metal structure were analyzed during melting/solidifying phenomena at two Reynolds numbers (Re = 200 and 400). The relevant findings are discussed for the LTNE intensity and the entropy generation rate (Ns). Through the simulations, the LTNE hypothesis turned out to be secure and valid. In addition, it is maximum for small PPI value (=10) whatever the parameters deemed. On the other hand, high porosity (=0.9) is advised to reduce the system’s irreversibility. However, at a moderate Re (=200), a small PPI (=10) would be appropriate to mitigate the system irreversibility during the charging case, while a large value (PPI = 60) might be advised for the discharging case. In this context, it can be stated that during the melting period, low porosity (=0.7) with low PPI (=10) improves thermal performance, reduces the system irreversibility and speeds up the melting rate, while for high porosity (=0.9), a moderate PPI (=30) should be used during the melting process to achieve an optimal system.

Siamese-SR: A Siamese Super-Resolution Model for Boosting Resolution of Digital Rock Images for Improved Petrophysical Property Estimation

Digital Rock Physics leverages advances in digital image acquisition and analysis techniques to create 3D digital images of rock samples, which are used for computational modeling and simulations to predict petrophysical properties of interest. However, the accuracy of the predictions is crucially dependent on the quality of the digital images, which is currently limited by the resolution of the micro-CT scanning technology. We have proposed a novel Deep Learning based Super-Resolution model called Siamese-SR to digitally boost the resolution of Digital Rock images whilst retaining the texture and providing optimal de-noising. The Siamese-SR model consists of a generator which is adversarially trained with a relativistic and a siamese discriminator utilizing Materials In Context (MINC) loss estimator. This model has been demonstrated to improve the resolution of sandstone rock images acquired using micro-CT scanning by a factor of 2. Another key highlight of our work is that for the evaluation of the super-resolution performance, we propose to move away from image-based metrics such as Structural Similarity (SSIM) and Peak Signal to Noise Ratio (PSNR) because they do not correlate well with expert geological and petrophysical evaluations. Instead, we propose to subject the super-resolved images to the next step in the Digital Rock workflow to calculate a crucial petrophysical property of interest, viz. porosity and use it as a metric for evaluation of our proposed Siamese-SR model against several other existing super-resolution methods like SRGAN, ESRGAN, EDSR and SPSR. Furthermore, we also use Local Attribution Maps to show how our proposed Siamese-SR model focuses optimally on edge-semantics, which is what leads to improvement in the image-based porosity prediction, the permeability prediction from Multiple Relaxation Time Lattice Boltzmann Method (MRTLBM) flow simulations as well as the prediction of other petrophysical properties of interest derived from Mercury Injection Capillary Pressure (MICP) simulations.

TLBfind: a Thermal Lattice Boltzmann code for concentrated emulsions with FINite-size Droplets

In this paper, we present TLBfind, a GPU code for simulating the hydrodynamics of droplets along with a dynamic temperature field. TLBfind hinges on a two-dimensional multi-component lattice Boltzmann (LB) model simulating a concentrated emulsion with finite-size droplets evolving in a thermal convective state, just above the transition from conduction to convection. The droplet concentration of the emulsion system is tunable and at the core of the code lies the possibility to measure a large number of physical observables characterising the flow and droplets. Furthermore, TLBfind includes a parallel implementation on GPU of the Delaunay triangulation useful for the detection of droplets' plastic rearrangements, and several types of boundary conditions, supporting simulations of channels with structured rough walls. Program summaryProgram Title: TLBfindCPC Library link to program files:https://doi.org/10.17632/hbk45696nf.1Developer's repository link:https://github.com/FrancescaPelusi/TLBfindLicensing provisions: MITProgramming language: CUDA-CNature of problem: Hydrodynamics of concentrated emulsions with finite-size droplets in a thermal convective state.Solution method: Single relaxation time Lattice Boltzmann method to solve Navier-Stokes equations for fluids, coupled with the temperature field dynamics. The output describes the dynamics of finite-size droplets of concentrated emulsions in presence of a temperature field. The temperature field obeys the advection-diffusion equation.Additional comments including restrictions and unusual features: Plastic rearrangements of droplets are detected via the parallel implementation of the Delaunay triangulation, and boundary conditions are tunable.

Effect mechanism of multiple obstacles on non-Newtonian flow in ceramic 3D printing (arcuate elements)

Direct ink writing (DIW), as an additive manufacturing method, can effectively mould ceramic parts. The single screw extruder is used here to extrude viscous SiC slurry. The deposits caused by the low viscosity and the agglomerations resulting from the nonuniform mixing, form the obstacles in the channel, which affect the normal theoretical flow of the slurry, and interaction with other printing parameters. Therefore, it is necessary to explore the effect mechanism of the obstacles on the flow. The obstacles are always irregular, which makes it difficult to directly analyse them. The irregular geometries are always composed of linear and/or arcuate elements; therefore, the obstacles can be simplified into regular geometries. In the previous work, linear elements have been analysed first. As the continuous work, arcuate elements are investigated in the current research. To conduct the required simulations, an improved MRT LBM (multiple relaxation time lattice Boltzmann method) with a pseudo external force is proposed. The above numerical method is combined with the rheological model to analyse cases with two obstacles, and the obtained results are used to reveal the general mechanism in cases with multiple obstacles. The results show that the central angles, radii, and positions of the obstacles are important factors affecting the flow. To obtain a stable and controllable slurry flow, it is recommended that the central angle and the radius should be small enough. The number of obstacles should be minimized, and the position of the last obstacle is expected to be far away from the outlet to avoid the negative velocity. In addition, the adjacent obstacles should maintain a certain distance to ensure the full development of the vortex and avoid affecting the following obstacles or back vortices.

Numerical Simulation of Adsorption and Heat Transfer in Porous Media Using Lattice Boltzmann Method

An adsorption model for fluid flow, heat, and mass transfer of the adsorbent bed was established. Based on the single relaxation time lattice Boltzmann method, a dual-distributed lattice Boltzmann model of density and concentration was established to solve the fluid flow and mass transfer process in the surface area of the adsorbent bed. The adsorption and heat transfer process on the surface of the adsorbent bed was incorporated into the dual-distributed lattice Boltzmann model by the fourth-order Runge-Kutta finite difference method. The multiphysics fields under Poiseuille flow were simulated by the presented model, and the adsorption capacity and temperature distribution during the adsorption process were investigated.