3D Numerical Model Research Articles

Integrated modelling of CO2 plume geothermal energy systems in carbonate reservoirs: Technology, operations, economics and sustainability

The rising CO2 content in the atmosphere calls for urgent decarbonization efforts. Carbon capture and storage (CCS) have proven effective in storing large volumes of CO2 in geological reservoirs. Nevertheless, challenges persist in identifying sustainable energy sources and efficient storage sites, especially in carbonate reservoirs. This study aims to characterize the Miocene carbonate reservoir in the Jintan Megaplatform, for CO2 storage and geothermal energy utilization. By integrating advanced technologies such as CO2 Plume Geothermal (CPG) with 3D seismic techniques, borehole analysis and numerical modelling, the study reveals the distribution of critical reservoir characteristics, including architecture, heterogeneity, karstification, fractures, porosity, permeability, temperature and pressure that are paramount for CO2 plume and energy production. The reservoir is estimated to store over 31 Gt of CO2, produce 3.824 × 1018 J of geothermal energy and ⁓44.3 GW of power. This power output can be utilized for electrification of the CCS operations, industrial and municipals, potentially generating over $1.4 billion in revenue. A flow-through model has been proposed to improve energy efficiency, reservoir management, and risk mitigation. This study advances to achieving net-zero targets and the United Nations Sustainable Development Goals on clean energy, climate action and sustainable communities.

3D Numerical Modeling of the Inertial and Kinematic Interactions of Inclined Pile Groups in Liquefiable Soils

3D Numerical Modeling of the Inertial and Kinematic Interactions of Inclined Pile Groups in Liquefiable Soils

The gas hydrate system of the western Black Sea Basin

The basin-scale distribution of gas hydrates and methane migration pathways in the western Black Sea remains enigmatic, owing to the region's complex geological history. Characterizing the abundant gas hydrate accumulations across temporal scales poses significant challenges. In this study, we developed and applied a 3D large-scale numerical model to study the formation, development, and fate of natural gas hydrate systems in the western Black Sea sub-basin. Our model enables us to simulate the dynamic evolution of basin geometry and facies distribution over the last 98 million years and under dynamically changing boundary conditions, e.g. due to sea-level changes. Our study estimates the total volume of gas hydrates stored within western Black Sea sediments at ∼14,607 MtC, equivalent to ∼30,073 × 1011 m3 of CH4 (at STP conditions) which is about 5 times higher than average gas hydrate density at continental margins. Our findings reveal three distinct mechanisms driving gas hydrate reservoir formation within the reconstructed sub-basin: gas hydrate recycling zones, chimney-like structure formation, and gas hydrate deposits associated with paleo-deep sea fans. We identified and simulated key controlling parameters, related to methane migration pathways and regional geomorphology, governing each type of hydrate formation. Subsequently, we conduct a detailed analysis of regional gas hydrate systems, focusing on the Dniepr paleo-fan system, the Danube paleo-fan region, multiple offshore locations near Turkey, and the central Black Sea area. Furthermore, we investigate various biogenic methane formation kinetics and their impact on basin-scale methane generation. Our sensitivity studies enable us to predict the optimal temperature range for microbial activity driving methanogenesis in the Black Sea sediments at 30 °C–40 °C. Overall, our study provides a novel understanding and quantitative correlation between methane generation, migration, and storage in the form of gas hydrates on a basin-scale in the western Black Sea.

3D Numerical Modeling to Assess the Energy Performance of Solid–Solid Phase Change Materials in Glazing Systems

This research investigates the energy efficiency of a novel double-glazing system incorporating solid–solid phase change materials (SSPCMs), which offer significant advantages over traditional liquid–solid phase change materials. The primary objective of this study is to develop a 3D numerical model using the finite volume method, which will be followed by a parametric study under real climatic boundary conditions. A proposed double-glazing setup featuring a 2 mm layer of SSPCM applied on the inner glass pane within the air gap is modeled and analyzed. The simulations consider various transient temperatures and ranges of the SSPCM to evaluate the energy performance of the system under different weather conditions of Miami, FL during the coldest and hottest days of the year, both in sunny and cloudy conditions. The results demonstrate a notable improvement in energy performance compared to standard double-glazing windows (DGWs), with the most efficient SSPCM configuration exhibiting a phase transition temperature and range of 25 °C and 1 °C, respectively. This configuration achieved energy savings of 24%, 26%, and 23% during summer sunny, winter sunny, and winter cloudy days, respectively, relative to DGWs during cooling and heating degree hours. However, a 3% energy loss was observed during summer cloudy days. Overall, the findings of this study have shown the potential for energy savings by incorporating SSPCM with suitable thermophysical properties into double-glazing systems.

Opening and Post-Rift Evolution of Alpine Tethys Passive Margins: Insights from 1D Numerical Modeling of the Jurassic Mikulov Formation in the Vienna Basin Region, Austria

This study employed 1D numerical pseudo models to examine the Upper Jurassic carbonate succession, focusing on the Mikulov Formation in the Vienna Basin region. It addresses the protracted and complex history of the Jurassic source rock play, revealing a transition from rapid syn-rift (>200 m/Ma) to slower post-rift sedimentation/subsidence of the overlying layers during extensional deformation (up to 120 m/Ma with a thickness of 1300 m). This provides valuable insights into the rift-to-drift stage of the central Alpine Tethys margin. The Mikulov marls exhibit characteristics of a post-rift passive margin with slow sedimentation rates. However, a crustal stretching analysis using syn-rift heat flow sensitivity suggested that thermal extension of the basement alone cannot fully explain the mid-Jurassic syn-rift stage in this segment of the Alpine Tethys. The sensitivity analysis showed that the mid-late Jurassic differential syn-rift sequences were exposed to slightly cooler temperatures than the crustal stretching model predicted. Heat flow values below 120 mW/m2 aligned with measurements from deeply settled Mesozoic successions, suggesting cold but short gravity-driven subsidence. This may account for the relatively low thermal maturation of the primary source rock interval identified by the time-chart analysis, despite the complex tectonic history and considerable sedimentary burial. The post-Mesozoic changes in the compaction trend are possibly linked to the compressional thrusting of the Alpine foreland and postdating listric faulting across the Vienna Basin.

Forming mechanism of single-channel multilayer laser cladding Fe60 process under different laser heat source operating mode

Continuous wave (CW) and pulsed wave are the two principal modes of operation used to control the laser heat source. Different laser heat source operating modes have an essential impact on the rapid cooling and heating temperature change rate during the cladding process, which directly determines the cladding layer quality. The laser cladding process is meaningful to quantitatively reveal the mechanism of single-channel multilayer cladding and forming under different laser heat source operating modes. In this article, a multi-field coupled 3D numerical model of the single-channel multilayer cladding process under different laser operating modes was proposed, and the thermal physical parameters of the cladding material were computed on the basis of Calculation of Phase Diagrams method. The mechanism of the impact of distinct operating modes on the multi-field coupled ephemeral evolution process of laser cladding was investigated by using the solid/liquid interface tracking technique, which comprehensively considers the light powder interaction between the powder waist beam and the laser beam under different operating modes. The temperature, flow, and stress fields were computationally solved for a single-channel multilayer cladding process. On the foundation of this study, the impact mechanism of pulse duty cycle and pulse frequency on the cladding behavior of single-channel and multilayers during pulsed laser cladding were dissected. The macroscopic morphology and microstructure of the cladding layer were observed by KEYENCE VH-Z100R ultra-deep field electron microscope, and the feasibility of the model was confirmed. This study provides a significant theoretical rationale for enhancing the cladding quality under different laser operating modes.

In-situ test and numerical investigation on the long-term performance of deep borehole heat exchanger coupled heat pump heating system

Given the substantial initial investment required by the drilling and implementation of the Deep Borehole Heat Exchanger (DBHE), it becomes imperative to quantitatively evaluate its long-term performance and sustainability. This work introduces a pilot DBHE project in Xi’an, along with the 500-h in-situ monitored data, which is used to validate the 3D numerical model established and simulated in the OpenGeoSys (OGS) software. Based on the validated model, a series of extended scenarios are executed to evaluate the influence of design and operational parameters on the long-term performance and sustainability of the DBHE system. The results show that the drilling depth is the most significant factor that influences long-term performance. On the contrary, pipe diameter and inner pipe thermal conductivity have a very limited impact. A comprehensive evaluation is suggested to determine operational flow rates in real projects while considering the energy consumption by the circulation pump. Moreover, the heat extraction performance and energy analysis of the DBHE coupled with a geothermal heat pump under intermittent operation are also investigated. With a fixed daily heating demand, a longer daily operating time results in lower circulating temperature drops, which is advantageous for the heat pump’s energy efficiency in long-term operation.

Analytical vulnerability functions for assessing fatalities in masonry buildings

AbstractThe assessment of human losses and injuries due to earthquakes is critical for the development of risk reduction measures. Yet, most vulnerability studies have focused on the derivation of fragility functions for structural damage, neglecting the evaluation of the human impact. In this study, we implemented a fatality vulnerability assessment procedure based on advanced structural modelling, with an application to typical limestone and granite masonry buildings in Portugal. We performed nonlinear time‐history analysis on 3D numerical models whose characteristics were sampled from statistical models representing the geometric and mechanical properties of this type of construction. Engineering demand parameters, such as volume of loss and volume of survivable space, were estimated and converted into a fatality rate based on observations from past fatal earthquakes. We compared these vulnerability functions with other proposals from the literature in which conventional fragility functions are directly combined with collapse and fatality rates. Finally, the resulting vulnerability functions were tested for two earthquake scenarios for Portugal. The results from this study indicate that the conventional approach for fatality modelling tends to underestimate human losses for strong ground shaking due to the inability to account for catastrophic structural collapses. The fatality vulnerability functions developed in this work can be directly used in probabilistic seismic risk analysis or the assessment of earthquake scenarios.

Geometrization of a 3D numerical model of an underground facility based on the results of terrestrial laser scanning

Abstract The article proposes a method of combining CloudCompare, RHINO, and FLAC3D software, aimed at building numerical models of underground objects of natural or engineering origin, based on the results of measurements made using terrestrial laser scanning technology. This technology is one of the most advanced in mine survey as it enables accurate mapping of even the most complex geometries of underground facilities. This opens wide possibilities in the construction of more accurate numerical models of the behavior of the rock mass around such underground objects. The results of simulation of the behavior of the rock mass around the analyzed excavations, obtained by performing numerical calculations, allow predicting unfavorable phenomena that may occur as a result of the destruction of the rock mass and which may threaten the safety of users of underground facilities, for example, caves, tunnels, and mining excavations. In this work, we carried out measurements using a terrestrial laser scanner and obtained a “point cloud” that reproduced the geometry of the underground facility. An example is a fragment of the adit St. Johannes, which is part of the underground tourist route “Geopark” St. Johannes Mine in Krobica in Lower Silesia in Poland in the neighborhood of Gierczyn and Przecznica. In the next step, the measurement results were processed, so that it was possible to import the generated geometry into the FLAC3D software and use it to build a numerical model of the adit, based on “brick” zones. The aim of the article is to present in detail the methodology of geometrization of numerical models of underground objects with complex geometry. The author wanted the method to be as easy to use as possible, give full control over the surface structure, and not require many numerical modeling programs.

2D and 3D numerical modelling for preliminary assessment of long-term deterioration in Irish glacial till geotechnical slopes

ABSTRACT Long-term geotechnical slope deterioration, influenced by weathering and meteorological factors, presents stability challenges to infrastructure. Wetting and drying cycles lead to pore water pressure variations, causing deformations and slope failure. Studies on glacial tills which investigate deterioration in geotechnical slopes focus on variables like pore water pressure, soil water retention, compaction, freeze–thaw cycles and cracking. This research conducts a preliminary assessment of an Irish glacial till-cut slope, establishing a data-driven foundation for long-term slope behaviour studies. Data analysis, geospatial modelling and numerical simulations were performed on a cut slope in Castleblayney (Ireland), considering short-term/undrained and long-term/drained conditions. FLAC/Slope and Scoops3D were used for 2D and 3D slope stability analyses, applying the First-Order Second Moment (FOSM) probabilistic approach to assess how minor soil property changes affect slope stability, including long-term deterioration scenarios. The study underscores the importance of precise instrument placement within Irish glacial till geotechnical cut slopes, particularly at the uppermost part where shallow and deep failures coincide under long-term and short-term scenarios. This informs strategic instrument positioning for accurate slope deterioration investigations. This research lays the groundwork for understanding mechanisms driving geotechnical slope deterioration and provides insights for future studies on geotechnical asset deterioration models in Irish glacial tills.

Parallel Implicit Solvers for 2D Numerical Models on Structured Meshes

Parallel Implicit Solvers for 2D Numerical Models on Structured Meshes

Integration of acoustic micromixing with cyclic olefin copolymer microfluidics for enhanced lab-on-a-chip applications in nanoscale liposome synthesis

The integration of acoustic wave micromixing with microfluidic systems holds great potential for applications in biomedicine and lab-on-a-chip technologies. Polymers such as cyclic olefin copolymer (COC) are increasingly utilized in microfluidic applications due to its unique properties, low cost, and versatile fabrication methods, and incorporating them into acoustofluidics significantly expands their potential applications. In this work, for the first time, we demonstrated the integration of polymer microfluidics with acoustic micromixing utilizing oscillating sharp edge structures to homogenize flowing fluids. The sharp edge mixing platform was entirely composed of COC fabricated in a COC-hydrocarbon solvent swelling based microfabrication process. As an electrical signal is applied to a piezoelectric transducer bonded to the micromixer, the sharp edges start to oscillate generating vortices at its tip, mixing the fluids. A 2D numerical model was implemented to determine the optimum microchannel dimensions for experimental mixing assessment. The system was shown to successfully mix fluids at flow rates up to 150 µl h−1 and has a modest effect even at the highest tested flow rate of 600 µl h−1. The utility of the fabricated sharp edge micromixer was demonstrated by the synthesis of nanoscale liposomes.

The effects of three-dimensional bedding on shale fracture behavior: Insights from experimental and numerical investigations

The three-dimensional (3D) structural characteristics of the bedding planes exhibit strong anisotropy in the fracture behavior of shale. Previous studies on the anisotropy of shale fracture characteristics focused on 2D bedding effects, while 3D bedding effects that comprehensively consider bedding angles α and β have been rarely investigated. Therefore, the fracture behavior of shale with 3D bedding planes was studied based on laboratory experiments and numerical simulation. The results indicated that the apparent fracture toughness (AFT) of shale decreased with increasing bedding angle α. The fracture toughness of shale with a bedding angle of α = 0° was 2.26 MPa·m0.5 (β = 0°). However, when the loading angle α increased to 90°, the AFT decreased by 67.70 %. The increase in bedding angle β could improve the AFT significantly, and the higher the loading angle α, the more significant the improvement. The improvement amplitude at α = 90° reached 156.65 %. Due to the enhanced ability of shale to resist crack propagation by the bedding angle β, the trend of dissipation energy under the influence of 3D bedding effects was consistent with the AFT, and the two were positively correlated. Affected by the 3D bedding effect, three typical failure modes of shale have been observed: bedding failure, matrix failure, and mixed failure mode. Based on the calculation of the fractal dimension of the fracture surface, the roughness of the fracture surface under different failure modes was mixed failure > matrix failure > bedding failure. In addition, a 3D numerical model was established based on the DEM method, and the influence of new cracks on fracture toughness was considered after verifying the effectiveness of the numerical model. The length of newly formed cracks at the tip of shale prefabricated cracks exceeded 4.0 mm under critical load. Ignoring the length of new cracks will underestimate the fracture toughness of shale by about 30 %. Finally, the influence of 3D bedding planes on the crack propagation path was discussed.

3-Dimensional numerical study on carbon based electrodes for vanadium redox flow battery

Electrode materials are critical in determining the performance of Vanadium redox flow batteries (VRFB). This work aims at elucidating the difference between carbon-based electrodes for VRFB. The electrodes considered for the present study are Graphite felt, Carbon felt, Carbon paper, and Carbon cloth. To study the characteristic behavior of different electrode materials, a 3D unit cell numerical model was developed by coupling electrolyte flow and electrochemical reactions and mass transfer module apart from considering the electrode structural and material information such as porosity, permeability, thickness, conductivity, and specific area. The simulation results of this study suggest that the Graphite felt is the optimum choice as an electrode material for VRFB as it offers higher electrocatalytic activity, lower pressure drop, better performance, and lower cost. The study is also extended to a multilayer configuration of Carbon Paper and Carbon Cloth. The performance of multi-layered electrodes by stacking single sheets of Carbon Paper and Carbon Cloth electrodes are matched to meet the performance obtained with the Graphite felt electrode. It has been shown with the help of polarization curve and the pressure drop study that the performance of five layers of carbon cloth and nine layers of carbon paper match the performance of Graphite felt, approximately. The present study provides practical guidance for the design and optimization of VRFB electrodes.

Large dump critical zone of interest identification and slope failure prediction using realistic 3D numerical modelling

Dump failure is one of the most catastrophic hazards in the opencast mining industry and involves sudden and violent failures. Therefore, susceptible region identification is essential for slope failure mitigation in the large dump. This study proposed a sustainable approach for large dump critical zone of interest (CZI) identification, stability monitoring and slope failure prediction. UAV close-range photogrammetry survey and structure-from-motion (SfM) approach were used for the dump realistic 3D model reconstruction. 3D numerical modelling was employed for dump stability analysis. In this investigation, the dump critical zone, slope factor of safety (FOS), displacement and slope failure prediction were analysed using the 3D numerical modelling. The results indicate that maximum displacement was found in the critical zone I. However, the dump was stable under static conditions. Dump critical slope failure time is predicted using the inverse velocity method. The results of this investigation are reliable and establish the scope of UAV photogrammetry for realistic 3D modelling. In addition, the slope stability state and failure model were consistent with field observations. The proposed approach can be used for the mine, hill, and roadcut slopes. UAV technology and 3D modelling approaches have substantially reduced data collection time and expense.

Performance investigation of metal foam coupled to phase change material as coolant of photovoltaic concentrator systems: Optimization and electrical efficiency analysis

This research investigates the integration of graphitic metal foam with paraffin RT35HC to manage and reduce the temperature of PV cells, focusing on the rigorous examination of the synergistic effects of metal foam porosity and panel inclination on thermal management. A 2D numerical model was developed using ANSYS Fluent 14.0, where User-Defined Functions (UDFs) were employed to incorporate the Darcy-Brinkman-Forchheimer and Carman-Kozeny equations, accurately accounting for the effects of metal foam porosity on thermal conductivity and fluid flow resistance. Various foam porosities (ε = 0.80, 0.85, 0.90, 0.95, 1) were explored on both vertical and tilted panels across a spectrum of inclination angles (β= 0°, 30°, 45°, 75°, 90°). Results highlight critical parameters including PCM melting fraction, cell temperature evolution, and the resultant impact on solar cell electrical efficiency, both with and without metal foam. The integration of graphitic foam with RT35HC contributed to superior heat transfer and a marked reduction in cell temperature of the employed PV system by improving thermal conductivity and heat dissipation, particularly at slight inclination angles (β =0° to 30°), revealing a noteworthy enhancement in electrical efficiency ranging from 1.3 % to 3 %, respectively. Conversely, the absence of graphitic foam at steeper angles (β =45° to 90°) surprisingly strengthens the solar panel’s electrical performance. These findings provide valuable insights into the effects of metal foam integration at varying inclination angles, offering a pathway for the development of more efficient and reliable solar energy systems.

Micromechanical modeling of longitudinal tensile behavior and failure mechanism of unidirectional carbon fiber/aluminum composites involving fiber strength dispersion

This paper examines the longitudinal tensile behavior and failure mechanism of a new unidirectional carbon fiber reinforced aluminum composite through experiments and simulations. A Weibull distribution model was established to describe the fiber strength dispersion based on single-fiber tensile tests for carbon fibers extracted from the composite. The constitutive models for the matrix and interface were established based on the uniaxial tensile and single-fiber push-out tests, respectively. Then, a 3D micromechanical numerical model, innovatively considering the fiber strength dispersion by use of the weakest link and Weibull distribution theories, was established to simulate the progressive failure behavior of the composite under longitudinal tension. Due to the dispersion of fiber strength, the weakest link of the fiber first fractures, and stress concentration occurs in the surrounding fibers, interfaces, and matrix. The maximum stress concentration factor for neighboring fibers varies nonlinearly with the distance from the fractured fiber. Both isolated and clustered fractured fibers are present during the progressive failure process of the composite. The expansion of fractured fiber clusters intensifies stress concentration and material degradation which in turn enlarges the fractured fiber clusters, and their mutual action leads to the final collapse of the composite.

Failure of Daliang tunnel induced by active stick–slip fault

In earthquake-prone areas, mountain tunnels often suffer from seismic damage when traversing active fault zones. To capture the seismic behavior of mountain tunnel under the action of active faults motion, the rate and state friction (RSF) relation is introduced to define the stick–slip dynamic behavior of a fault. The RSF relation is implemented in the finite element methods (FEMs). Numerical simulations of triaxial patch tests indicate that the RSF method can effectively capture the stick–slip dynamics. To reproduce the seismic damage to Daliang tunnel caused by slip of the Lenglongling fault, a three-dimensional (3D) numerical model including tunnel structure and plates of the fault is established. Seismic waves triggered by fault slip are then reproduced using the model. The simulation results show that the waves are dissipated while travelling and that their amplitudes decrease with depth. The failure of the tunnel lining is captured, and its seismic responses, including the displacement and strain of the structure, are extracted for various fault strike angles. The simulations are consistent with the observations, and it indicates that the movement of the simulated tunnel structure adjacent to the fault surface is significantly greater than those in the foot wall and in the middle of the fault. This study has the potential to provide a more direct means of understanding the seismic action of infrastructure induced by earthquakes. Seismic waves are no longer needed as input to the numerical simulation and instead, the earthquakes are generated by directly modeling the stick–slip motion of the fault.

Examples of dynamic test procedures for steel fibre reinforced concrete

Abstract The aim of this work is to present some examples of experimental tests, which can be usefull for characterizing the resistance to failure of special steel fibre reinforced concrete – SFRC, intended especially for security use in the framework of ballistic and explosion protection. The first type of the tests was the strain gauge - based characterization of the dynamic response of the SFRC concrete block under ballistic loading. The tests were aimed at measuring the deformation response of a concrete specimen of 500 x 500 x 105 mm in dimensions upon the impact of a projectile. The tests were used to support the development and verification of numerical simulation models. For numerical simulations 3D models of individual projectiles were developed. Four T-type strain gauges were glued according to the geometric scheme on the opposite side of a specimen, i.e. on the side behind the impact of the projectile, and they measured the deflection of the plate after the impact of the projectile. The strain response records obtained from the strain gauges were subsequently used for numerical analyses by the use of the LS-DYNA software. The average maximum deflection of the plate at the impact of the projectile was characterized by the strain 400 µm/m. The second type of the tests was concerned with the method of measuring the quasi-dynamic tensile strength of special concrete specimens using an instrumented Charpy tester. The results compare both the breaking energy and the maximum force achieved for hobby concrete (HB) and hobby concrete with wires (HBD) specimens. These were pilot tests to develop the most suitable testing method. For the HB and HBD specimens the maximum force in the tests was found to be 55 N vs. 600 N, and the breaking energy to be 0.4 J vs. 1.3 J.

A 2D numerical model for simulating landslide dam failure and induced morphological changes considering multi-layer and non-uniform sediments

ABSTRACT Landslide dams are formed by the blockage of rivers with landslides or any debris flows. Such dams are prone to failure and therefore, simulation of their failure and induced morphological changes is of great importance for hazard mitigation. Multi-layer and non-uniform sediments are usually observed in landslide dam materials, but these are rarely considered in simulations. In this paper, a two-dimensional numerical model considering multi-layered and non-uniform sediments is proposed. The model solves the shallow water equations, the Exner equation considering the different size fractions and Hirano's active layer equation based on a finite volume scheme in a weakly coupled approach. Two experimental tests are used to assess the applicability and accuracy of the model. The results show that it can well simulate the flow and morphological changes, as well as the surface coarsening and fining phenomena related to multi-layer and non-uniform sediments. The numerical results of dam failure process and morphological changes are in overall good agreement with the experiments, but the peak discharge and bed elevation tend to be underestimated when finer material is considered. Finally, the influence of sediments fractions and active layer depth on numerical results, as well as the limitations of the model are discussed.