Article
Engineering, Chemical
Elham Kashani, Ali Mohebbi, Amir Ehsan Feili Monfared, Amir Raoof
Summary: A novel kinetic level method is proposed in this study to implement nonlinear boundary conditions such as n(th)-order surface reactions or surface radiation heat transfer. The method combines Taylor expansion of the conditions with a counter-slip approach to find unknown distribution functions at boundary nodes. Experimental results show promising performance in terms of accuracy and convergence speed when dealing with surface reactions and radiation heat transfer.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Thermodynamics
G. Gruszczynski, L. Laniewski-Wollk
Summary: In this study, possible remedies for numerically challenging thermal flows characterized by high Prandtl number are explored using novel collision kernels, lattices with a large number of discrete velocities, and second-order boundary conditions. The importance of higher order moments in the solution of the macroscopic advection-diffusion equation is confirmed, and a kernel based on the two relaxation time approach is shown to be superior in numerical simulations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Multidisciplinary
Oliver Boolakee, Martin Geier, Laura De Lorenzis
Summary: We propose novel, second-order accurate boundary formulations for Dirichlet and Neumann boundary conditions on arbitrary curved boundaries. The proposed methodology is based on the asymptotic expansion technique and is expected to have general applicability beyond the scope of this paper. We develop a modified version of the bounce-back method for Dirichlet boundary conditions, and a novel generalized ansatz for Neumann boundary conditions that requires information from one additional neighbor node.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Physics, Multidisciplinary
Bowen Liu, Weiping Shi
Summary: In this paper, an explicit correction force scheme of the combined IB-LBM method was proposed to improve the numerical simulation of fluid-structure interaction. The method introduced particle distribution function and applied LBM force models to calculate interface force. A correction matrix was used to ensure mass conservation in the interface area. The method was validated through numerical tests and successfully simulated complex boundary conditions for both movable rigid bodies and flexible deformable bodies.
Article
Mathematics, Interdisciplinary Applications
Erik Faust, Alexander Schlueter, Henning Mueller, Felix Steinmetz, Ralf Mueller
Summary: Recently, Murthy et al. and Escande et al. utilized the Lattice Boltzmann Method (LBM) to model the linear elastodynamic behavior of isotropic solids. The LBM allows for parallelization and finely discretized simulations of dynamic effects, making it an attractive elastodynamic solver. This study proposes local boundary rules for the LBM to approximate Dirichlet and Neumann boundary conditions for elastic solids, which are shown to be consistent with the target boundary values in the first order. Convergence studies and comparisons with analytical solutions are conducted.
COMPUTATIONAL MECHANICS
(2023)
Article
Mathematics, Applied
Xinyuan Xie, Weifeng Zhao, Ping Lin
Summary: This paper introduces a boundary scheme for Robin boundary conditions on curved boundaries in the lattice Boltzmann method, which avoids numerical instability due to zero denominators and ensures stability and accuracy. The proposed scheme is simple to implement, has first-order accuracy, and only requires information from the present point, demonstrating good stability and accuracy in numerical examples.
APPLIED MATHEMATICS LETTERS
(2021)
Article
Mechanics
Alexander Schlueter, Henning Mueller, Ralf Mueller
Summary: This paper presents two different approaches to treat boundary conditions in a lattice Boltzmann method for the wave equation. These algorithms provide more flexibility to handle geometries that do not conform with the lattice and improve the accuracy of the method.
ARCHIVE OF APPLIED MECHANICS
(2022)
Article
Engineering, Chemical
Jingrui Liu, Yimin Xuan, Liang Teng, Qibin Zhu, Xianglei Liu
Summary: The study used the lattice Boltzmann method to construct the carbonation process of a single calcium oxide particle, which has significant implications for understanding micro-flow diffusion mass transfer and heat release processes within pores.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Computer Science, Interdisciplinary Applications
Buchen Wu, Jinhua Lu, HsuChew Lee, Chang Shu, Minping Wan
Summary: This work proposes an efficient explicit boundary condition-enforced immersed boundary method for Neumann boundary condition in thermal-fluid-structure interaction (TFSI) problems with moving boundaries. The proposed method achieves high computational efficiency and similar accuracy as the original implicit IBM by avoiding the need to generate and invert a large correlation matrix. It can efficiently solve practical physics problems involving a large number of Lagrangian points with Neumann boundary condition.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Thermodynamics
Liang Wang, Shi Tao, Junjie Hu, Kai Zhang, Gui Lu
Summary: This work focuses on the discrete effects of curved boundary conditions in the lattice Boltzmann method for convection-diffusion equations. A new strategy is proposed to eliminate numerical slip, showing its effectiveness through mathematical derivations and simulations. The results support the proposed strategy's ability to achieve uniform relaxation times and remove numerical slip in cases of curved boundaries.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Computer Science, Interdisciplinary Applications
Liang Wang, Shi Tao, Junjie Hu, Kai Zhang, Gui Lu
Summary: In this paper, a local boundary condition for curved solid walls in slip flow regime of microgaseous flows is proposed and analyzed within the multiple-relaxation-time (MRT) model. The developed boundary treatment combines different schemes to achieve an accurate slip boundary condition. The theoretical analysis is supported by numerical examples showing good consistency with analytical solutions.
COMPUTERS & FLUIDS
(2021)
Article
Energy & Fuels
Raoudha Chaabane, Annunziata D'Orazio, Abdelmajid Jemni, Arash Karimipour, Ramin Ranjbarzadeh
Summary: Research focusing on fluid and nanoparticle interaction using numerical schemes has been intense in recent decades. This study highlights the thermal properties of CuO nanofluid under specific conditions, utilizing a mesoscopic approach to solve coupled equations and investigating convection phenomenon under new boundary conditions.
Article
Thermodynamics
Ping Wang, Ganggang Sun, Bo Dong, Lele Chen, Xuan Zhang, Boyuan Gong
Summary: In this study, the phase-change lattice Boltzmann method was used to simulate evaporation on a porous medium surface. A new wetting boundary scheme was proposed to consider surface wettability. The effect of surface wettability on evaporation in the porous medium was investigated, and it was found that reducing the contact angle of the porous media skeleton can increase the surface evaporation rate when the porous medium is hydrophilic. However, the benefit of decreasing the contact angle to improve the evaporation rate decreases as the contact angle of the skeleton decreases.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
Alessandro De Rosis, Alex Skillen
Summary: The flow physics generated by vortex-wall collision in an electrically conductive fluid is numerically investigated. The presence of a magnetic field is found to significantly modify the vortex dynamics, exerting a braking effect on the vortex that increases with the magnetic Prandtl number. The findings are linked to the energy transfer between the velocity and the magnetic fields as well as to the evolution of their enstrophies.
Article
Mathematics, Interdisciplinary Applications
Fengjiao Wang, He Xu, Yikun Liu, Chaoyang Hu
Summary: This paper presents a simplified method for determining lattice Boltzmann boundary conditions in order to address efficiency problems in fluid simulation. The method effectively combines the influence of rough surfaces, L-fractal theory, and a generalized lattice Boltzmann method. Numerical simulations demonstrate the reliability and flexibility of the proposed method. The effects of roughness and fractal dimensions on gas flow behavior are also investigated.
FRACTAL AND FRACTIONAL
(2023)
Article
Computer Science, Interdisciplinary Applications
Svetlana Kyas, Diego Volpatto, Martin O. Saar, Allan M. M. Leal
Summary: This work investigates the performance of the on-demand machine learning (ODML) algorithm in different reactive transport problems in heterogeneous porous media. The results show that even with strong heterogeneity, the ODML algorithm can significantly accelerate the calculations, thereby improving the efficiency of the entire reactive transport simulation.
COMPUTATIONAL GEOSCIENCES
(2022)
Article
Energy & Fuels
Mohamed Ezzat, Benjamin M. Adams, Martin O. Saar, Daniel Vogler
Summary: Drilling costs can be a significant portion of geothermal project investment, and reducing these costs through techniques like Plasma Pulse Geo Drilling (PPGD) can greatly decrease overall project expenses. This paper presents a numerical model to study how pore characteristics affect the efficiency of PPGD, which is a contactless drilling technique that uses high-voltage pulses to fracture rock without mechanical abrasion.
Article
Thermodynamics
Mark R. Fleming, Benjamin M. Adams, Jonathan D. Ogland-Hand, Jeffrey M. Bielicki, Thomas H. Kuehn, Martin O. Saar
Summary: CPG-F facility can generate more power than CPG power plant, but with less daily energy production. The capital cost of a CPG-F facility designed for varying durations of energy storage is 70% higher than a CPG power plant, but costs only 4% to 27% more than most CPG-F facilities designed for a specific duration, producing significantly more power than a CPG power plant.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Energy & Fuels
Justin Ezekiel, Benjamin M. Adams, Martin O. Saar, Anozie Ebigbo
Summary: CO2-Plume Geothermal (CPG) power plants can produce heat and/or electric power, with the CO2 mass flowrate being a crucial parameter for system design. The flowrate not only determines power generation, but also has a significant impact on fluid pressure drawdown and two-phase flow regime in the production well.
Article
Engineering, Geological
Anil Kumar, Roger Hu, Stuart D. C. Walsh
Summary: Fully coupled hydro-mechanical simulations of fractured media require sophisticated non-linear solvers to capture the complex relationship between fluid flow and material's mechanical response. Modelling these systems can be onerous, so a reduction strategy is necessary to predict physical response with less computational effort and time.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Review
Geochemistry & Geophysics
Shemin Ge, Martin O. Saar
Summary: This article provides a concise review of the triggering mechanisms of induced earthquakes, focusing on hydro-mechanical processes. Four mechanisms are reviewed: pore-fluid pressure diffusion, poroelastic stress, Coulomb static stress transfer, and aseismic slip. Several outstanding questions are discussed, and conclusions are drawn based on the review.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Water Resources
Hoda Javanmard, Martin O. Saar, Daniel Vogler
Summary: In this study, the heterogeneity of single rough rock fractures is parameterized using connectivity metrics for the first time. The results show that connectivity metrics can predict permeability with higher accuracy. All three studied connectivity metrics provide better permeability estimations when a larger aperture value is chosen as the cutoff threshold. Therefore, using connectivity metrics provides a less expensive alternative to estimate fracture permeability.
ADVANCES IN WATER RESOURCES
(2022)
Article
Mechanics
Mahsa Sakha, Morteza Nejati, Ali Aminzadeh, Saeid Ghouli, Martin O. Saar, Thomas Driesner
Summary: This study evaluates the accuracy of three fracture growth theories in predicting crack trajectories in anisotropic rocks through comparison with new experimental data. The results show that anisotropy can offset or reinforce the loading influence in determining the direction of crack growth, depending on the loading configurations. It is demonstrated that the modified forms of the maximum tangential stress (MTS) and maximum energy release rate (MERR) criteria give better predictions of fracture growth paths compared to the modified maximum strain energy density (MSED) criterion.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Civil
Isamu Naets, Mehrdad Ahkami, Po-Wei Huang, Martin O. Saar, Xiang-Zhao Kong
Summary: This study investigates the impact of shear displacement on flow path evolution within fractures through experimental observations and quantitative analyses. The results show that with increasing shear displacement, aperture variability and correlation length of fractures increase, leading to changes in fluid velocity variability, streamline tortuosity, and streamline spacing variability.
JOURNAL OF HYDROLOGY
(2022)
Correction
Engineering, Chemical
Po-Wei Huang, Bernd Flemisch, Chao-Zhong Qin, Martin O. Saar, Anozie Ebigbo
TRANSPORT IN POROUS MEDIA
(2022)
Article
Engineering, Chemical
Po-Wei Huang, Bernd Flemisch, Chao-Zhong Qin, Martin O. Saar, Anozie Ebigbo
Summary: Spatial scaling effects lead to discrepancies in mineral dissolution rates measured at different scales. In this study, we investigate the impact of pore-scale spatial heterogeneity in porous media on overall mineral dissolution rates, and propose a constitutive relation based on Darcy-scale reaction order to model reactive transport at the Darcy scale. Our results suggest that mineral spatial heterogeneity can be inferred from solute concentration measurements in flow-through dissolution experiments.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Engineering, Chemical
Xiang-Zhao Kong, Mehrdad Ahkami, Isamu Naets, Martin O. Saar
Summary: This study quantifies the transport of solutes in a 3D-printed fractured porous medium with high-permeability inclusions. The results show that compared to a high-permeability matrix, a low-permeability matrix has a higher solute concentration peak, a higher solute velocity peak, a smaller dispersion coefficient peak, a lower mixing rate, and a smaller solute-occupied pore volume.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Engineering, Civil
Sobhan Hatami, Stuart D. C. Walsh
Summary: This paper investigates the influence of geometry and flow conditions on the relative permeability of wetting and non-wetting components in fractures. Two new relative permeability models were introduced to accurately describe the behavior of wetting and non-wetting phases in fractures.
JOURNAL OF HYDROLOGY
(2022)
Article
Geochemistry & Geophysics
M. L. T. Dambly, F. Samrock, A. V. Grayver, M. O. Saar
Summary: The Main Ethiopian Rift is characterized by extensive volcanism and the formation of geothermal systems, directly impacting the lives of millions of people. Through the use of magnetotelluric method, a multi-scale 3D electrical conductivity model of a segment of the central Main Ethiopian Rift was obtained, revealing a magma ponding zone and its connection to Aluto volcano via a fault-aligned transcrustal magma system. This model provides important constraints for future geothermal developments and volcanic hazard assessments in the region.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Xiaodong Ma, Marian Hertrich, Florian Amann, Kai Broeker, Nima Gholizadeh Doonechaly, Valentin Gischig, Rebecca Hochreutener, Philipp Kaestli, Hannes Krietsch, Michele Marti, Barbara Naegeli, Morteza Nejati, Anne Obermann, Katrin Plenkers, Antonio P. Rinaldi, Alexis Shakas, Linus Villiger, Quinn Wenning, Alba Zappone, Falko Bethmann, Raymi Castilla, Francisco Seberto, Peter Meier, Thomas Driesner, Simon Loew, Hansruedi Maurer, Martin O. Saar, Stefan Wiemer, Domenico Giardini
Summary: The increased interest in subsurface development and associated seismicity requires a better understanding of hydro-seismo-mechanical coupling in fractured rock masses. In order to bridge the knowledge gap between laboratory and reservoir scales, controllable in situ experiments are necessary. The BedrettoLab provides a testing ground for studying the hydro-seismo-mechanical response of fractured crystalline rock masses.
