A novel hydro-mechanical model for multi-fracture dynamic evolution using the numerical manifold method

Advances in organic coatings for corrosion protection in deep-sea environments: Current status, strategies, and future perspectives.

Revisiting fluid flow regimes in porous media: Influence of surface roughness on fluid flow displacement

With the aim of identifying the strengths and limitations of current reactive transport models in simulating dissolution-precipitation reactions, this work validates experimentally a newly developed pore-scale reactive transport model. The model is developed in a way that limits uncertainty parameters, while accounting for all relevant pore-level physiochemical processes, namely, fluid flow, solutes transport, aqueous speciation, nucleation, and crystals dissolution/growth. The model is validated against two previous microfluidic experiments: one for dissolution only and the other for precipitation and dissolution. The main novelties of this work are: i) it provides modeling-experimental comparisons of simultaneous crystal growth and dissolution, ii) manages to replicate previous experimental results of calcite dissolution without parameters fine-tuning, and iii) provides a direct modeling-experimental comparison in appearance of the first crystallite via nucleation. From the novel numerical-experimental comparisons, this work highlights the knowledge gaps in the existing models and theories. From which, new research directions are recommended to improve, not only the modeling predictive capabilities, but also our current level of understanding of reactive transport processes.

The purpose of current study is to analyse the flow and thermal behaviour of Sutterby hybrid nanofluids, with particular attention given to an inclined magnetic field, viscous dissipation, heat source, Cattaneo-Christov heat flux, and thermal radiation model. In this work, we consider the Ag−Au/Blood based hybrid nanoparticle in the non-Newtonian Sutterby fluid in order to investigate how much they create the enhancement in the thermal conductivity. As the inclined magnetic field interacts with the electrically conducting fluid, its impacts on flow properties are examined. A more precise description of heat flow is obtained by using the Cattaneo-Christov model, which considers the speed limitations of heat conduction. The thermal transport analysis are investigated by using the thermal radiation, viscous dissipation and heat source or sink. The physical phenomena stated above have an impact on the formulation of the governing equations of mass, momentum and energy transfer. The model is established in the form of dimensional PDEs and suitable transformations is applied to translate the PDEs into non-dimensional ODEs. A mathematical model is created, and suitable numerical technique (Runge-Kutta 4th order) are used to find solutions. The findings demonstrate the combined impact of these variables on the fluid flow's temperature distribution, velocity profiles, and heat transfer rates. The results reveals that Lorentz force or retardation force causes the velocity profile to decrease as the magnetic field increases. When comparing the Ag/blood case to the Ag-Au/blood case based on the Sutterby Deborah number, the depth of the thermal boundary layer rapidly drops. The hybrid nanofluid's temperature rises while its velocity decreases due to the nanoparticle volume percentage parameter. The friction drag heightens along with the Sutterby Deborah number and Power-law index estimates.

Ultra-high-grade Au (UHG Au) is a texturally distinct vein-hosted Au mineralisation style in epithermal and orogenic Au deposits. The localised hyper-enrichment of Au appears to defy the Au transport capacity of typical ore-forming fluids; thus, the genesis of UHG Au remains debated. In this contribution, the genesis of UHG Au was investigated at the Beta-Hunt Au mine (Kambalda, Western Australia). The Beta-Hunt deposit hosts ∼2640 Ma, structurally controlled orogenic Au mineralisation with two distinct Au mineralisation styles: (1) low-moderate grade Au, occurring as isolated fine grains hosted within a hydrothermally altered shear foliation and (2) coarse-grained UHG Au hosted solely by albite-quartz-carbonate extension veins overprinting the foliation. We employed a multi-disciplinary methodology, conducting characterisation of vein morphology, microtextural analysis, μ-XRF mapping and 3D synchrotron X-ray tomography. Our observations show that UHG Au and associated gangue minerals precipitated within a sustained fluid-filled open space formed by progressively dilating, low aspect-ratio (length/width) fractures during a single or few opening-infill cycles. The low aspect-ratio geometry of UHG Au-hosting veins implies that viscoelastic wall rock deformation contributed to the dilation of the veins, establishing a stable mineral growth environment. Our observations deviate from the expectations of the current orogenic Au system model, which involves quasi-instantaneous fracturing and growth of veins, via rapid infilling during fluctuating pressure and chemical conditions. We explain our observations through a viscoelastic fracture growth model, which couples the generation of mineral growth space with sustained fluid flow for steady nutrient supply, extending the scope of current models for the genesis of UHG Au. • Description of Ultra-High-grade Au-bearing veins in mid-crustal orogenic Au deposit • Results show deposition of Au within veins with sustained open space • A viscoelastic fracture growth model is proposed to explain the development of veins

Enhanced design of a conical coil heat exchanger: A comprehensive analysis of conical angle and fluid flow arrangements

Geometric controls on fluid flow during extensional reactivation: insights from numerical modeling for carlin-type gold mineralization in the Lannigou deposit, southwestern Guizhou, China

Hydraulic infrastructures, such as embankments, dams, and levees, are highly vulnerable to suffusion under complex mechanical and hydraulic loading conditions, posing serious threats to their structural integrity. To better understand the underlying micromechanics of suffusion in gap-graded soils, this study investigates fine particle migration and microstructural evolution, with a focus on the effects of coarse particle shape and fines content. A coupled multibody dynamics and discrete element method framework is employed to generate soil specimens with varying fines contents and particle morphologies, while the suffusion process is simulated using the coupled computational fluid dynamics and discrete element method, enabling the thorough examination of the interactions between fluid flow, particle migration, and force chain evolution during seepage infiltration. The results reveal that the particle shape plays a crucial role in determining the stability of force chains and fine particle migration patterns. A novel motion-based classification of fine particle migration during suffusion is introduced, encompassing four distinct mechanisms: clogging, voiding, detour, and punching. Following a rapid fines loss period during early seepage infiltration, the remaining fine particles primarily stabilize in a clogging state. The concept of tortuosity is proposed to characterize migration complexity, with results showing a nonmonotonic relationship with particle aspect ratio. Additionally, a clogging ratio is developed to quantify the accumulation of fine particles in clogging states. This study provides insights into the complex behaviors of fine particle migration in gap-graded soils, establishing a foundational framework for a better understanding of suffusion dynamics in hydraulic infrastructures.

Double-pipe heat exchangers (DPHEs) are vital in industrial applications, and improving their performance is crucial for sustainability. This study uses three-dimensional Computational Fluid Dynamics (CFD) simulations to investigate the impact of passive flow modifications, specifically geometrically spaced and perforated ring inserts, on heat transfer and pressure drop in a DPHE. The research involved developing a 3D numerical model whose accuracy was ensured through a comprehensive mesh independence study and rigorous validation against established empirical correlations and experimental data. Subsequent simulations explored the influence of geometric spacing ( G -factor) and the number of perforations per ring. Results demonstrated that for unperforated rings P = 0 , uniform spacing maximised heat transfer, reaching a Nusselt number of 177.4 at a Reynolds number of 12,000. In contrast, strongly biased configurations exhibited superior overall performance by balancing thermal enhancement with hydraulic losses. These biased cases achieved a Performance Evaluation Criterion (PEC) of 1.065, equivalent to a 6.5% improvement compared with the uniform arrangement. The introduction of perforations significantly altered performance; a four-hole configuration with G = 1 . 00 consistently achieved the highest heat transfer and overall performance, with the Nusselt number rising to 195.8 and the PEC reaching 1.176, indicating an optimal balance between fluid mixing and flow resistance. By comparison, increasing the number of perforations further to eight reduced the pressure drop from 171 . 9 Pa for solid rings to 132 . 0 Pa , but had a less pronounced positive impact on heat transfer performance. For this configuration, the Nusselt number remained close to that of the unperforated case. Analysis of both turbulent kinetic energy (TKE) and velocity vector fields provided critical insights into the underlying mechanisms, illustrating how ring geometry and perforations disrupt boundary layers and generate beneficial turbulence. Furthermore, regression-based multivariate correlations for both the Nusselt number and friction factor were formulated as functions of Reynolds number, G -factor, and porosity. Validation against the full set of 75 CFD simulation cases demonstrated high accuracy, with 96% of the correlation-predicted Nusselt numbers deviating by less than ± 5 % from the corresponding CFD results, and the equivalent friction factor values deviating by less than ± 10 % . • Non-uniform ring spacing significantly affects DPHE thermo-hydraulic behaviour. • Four-hole perforated rings provide the best heat-transfer and pressure balance. • Strongly biased ring spacing yields higher overall PEC than weakly biased layouts. • CFD reveals mixing patterns driven by combined spacing and perforation effects. • Correlations predict Nusselt number and friction factor for 75 DPHE cases.

Numerical and experimental investigation of infiltration behavior in porous SiC preforms

Centrifugal-buoyancy instability on transient fluid flow and energy distribution through a strongly bent rectangular channel

Hydrothermal alteration is known to enhance conduit sealing and modulate phreatic eruptions. However, the timescales of alteration are poorly understood and difficult to constrain. Here, we use new field- and laboratory-based observations and analyses of fresh and altered lavas from Tongariro, New Zealand, to reconstruct the timescales, fluid composition, and impacts of alteration at this volcano. We focus on Tongariro as it hosts a moderate-sized hydrothermal system across a distributed vent complex. Importantly, it is the site of recent phreatic eruptions in 2012. Fresh Tongariro lavas ( ∼ 500 years old) contain variable plagioclase and pyroxene phenocrysts in an aphanitic groundmass with trace titanomagnetite. Respective altered equivalents are characterized by secondary phyllosilicate minerals, including kaolin-group minerals, and other phases such as pyrite and alunite, reflecting (advanced) argillic alteration caused by acidic fluid flow and/or acidic steam percolation at shallow depths at ∼ 150-200 ° C. Notable, albeit rare, hydrothermal carbonates are present (e.g., dolomite). The rates of alteration of the primary lavas (e.g., using stratigraphy and/or radiometric dating) indicate that hydrothermal alteration can occur within years to thousands of years. Our detailed analysis of secondary mineral assemblages indicates complex and temporally evolving hydrothermal fluid chemistry (including pH) and temperature. The analyzed secondary minerals represent alteration processes associated with the 2012 eruptions, which may have involved deep magmatic fluid discharge followed by neutral meteoric water. Understanding these processes provides insights into hydrothermal fluid circulation, alteration history, and potential volcanic hazards including flank collapse and phreatic eruptions. • Approximate timescales of alteration at Te Maari, Tongariro. • Identified alteration style and conditions. • Mass balance calculations applied to hydrothermal alteration reactions.

A PRISMA-based systematic review on future marine antifouling bioagents: Bioprospecting insights from corals and algae and ship hydrodynamic.

Enhancing the inner heterogeneous surface functionality of laser powder bed fused W-Cu minichannels by combining abrasive flow machining and electroless nickel deposition

Modulating cerebrospinal fluid flow by magnetohydrodynamic force

Electroosmotic-driven unsteady mass transport of non-Newtonian fluids flow through a microchannel under the influence of thermal buoyancy and slip-induced zeta potential

Neural network-based analysis for radiative entropy induced rheological material

This study provides the first integration of structural characterization and reactivity experiments applied to anorthosite formations for CO₂ mineralization assessment and outlines a framework that can be applied to other anorthosite bodies. Successful mineral sequestration requires two factors: 1) sufficient reactivity of the subsurface rocks and 2) fluid flow pathways for the injection and subsurface transport of pure or water-dissolved CO 2 . To assess the potential of mineral sequestration in massive anorthosites, we focused on the Khamal anorthosite batholith. This anorthosite is located near major CO₂ emission sources located in Yanbu, western Saudi Arabia. The reactivity of this batholith was tested by reacting ground cleaned batholith samples in aqueous Na₂CO₃ and NaHCO₃ solutions in batch reactors at 60 °C. Elemental analysis, scanning electron microscopy, and saturation index calculations based on aqueous geochemical data obtained from the experiments indicate substantial calcium carbonate formation can be attained. Unmanned Aerial Vehicle photogrammetric mapping of the batholith revealed its lithologies, faults and fractures. Notably, this detailed structural assessment identified a fracture corridor along a Tertiary fault cutting across the batholith that likely provides sufficient permeability for the injection of significant quantities of water dissolved CO₂ into the anorthosite. The success of this approach can be transferred to exploit the carbonation potential of other massive igneous bodies worldwide. • First integrated assessment of CO₂ mineralization potential in anorthosite formations. • UAV-based fracture mapping identifies viable pathways for CO₂-charged fluid injection. • Batch reactor experiments demonstrate measurable carbonation reactivity under mild conditions. • Presents a methodology for evaluating CO₂ disposal prospects in anorthosites worldwide.

Effects of soret and dufour on unsteady MHD free-convective transport of micropolar fluid past a porous plate with heat generation