Numerical Modeling Study Research Articles

Exploring Controls on Post‐Orogenic Topographic Stasis of the Pyrenees Mountains With Inverse Landscape Evolution Modeling

AbstractHow high topography can be sustained over long timescales in post‐orogenic mountain belts is a longstanding research question in tectonic geomorphology and geodynamics. Here we utilize the well‐documented orogenic paleo‐topography and spatial‐temporal exhumation patterns of the Pyrenee Mountains in a numerical modeling study investigating controls on post‐orogenic topographic stasis. Orogenic activity in the Pyrenees Mountains ceased at ca. 25‐20 Ma, but topographic decay has only been on the scale of hundreds of meters since that time. We use the landscape‐evolution model FastScape coupled with the neighborhood‐algorithm inversion method to explore the influence of precipitation, lithology, and stream power parameters on post‐orogenic topographic stability. The inversions are constrained using topography (elevation, slope) and low‐temperature thermochronology data. We find that incorporation of an erodibility threshold is required for moderating post‐orogenic topographic decay, without which post‐orogenic topography declines significantly on Myr timescales. While other evaluated parameters such as lithology and precipitation also contribute to topographic stability, they are secondary to the erodibility threshold in maintaining long‐term post‐orogenic topography. Our results provide valuable insights into the mechanisms governing post‐orogenic landscape evolution and emphasize the importance of thresholds in landscape evolution modeling of mountain belts.

Enhancing sand screen performance with integrated slurry testing and CFD-DEM modelling.

Understanding the behavior of sand screens is crucial for optimizing sand control strategies and preventing wellbore failure, which can significantly impact reservoir management and production efficiency. This paper presents a comprehensive experimental and numerical modeling study on sand screen performance, aimed at providing insights prior to real-field applications. The study evaluated a 200-μm wire-wrapped screen (WWS) using slurry tests to determine the amount of sand retained, sand produced and retained permeability to assess screen efficiency. The particle size distribution (PSD) of sand samples was crucial for selecting the appropriate screen size, with results showing that highly uniform and well-sorted sand exhibited higher sand retention and lower sand production due to reduced fines content and maximized void spaces, enhancing fluid flow while mitigating sand production. A coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) simulation platform was employed to model particle-fluid interactions, using an optimal mesh size of 0.005m. The simulation results showed a high degree of correlation with experimental data, with 93.1% similarity in sand retention and 63.22% in sand production. These findings underscore the potential of CFD-DEM simulations in accurately replicating complex sand control processes and optimizing screen performance for enhanced wellbore stability and production efficiency.

Corrigendum to “Mitigation of distortion of Al/steel part under simulated paint baking condition: Experiment and numerical model studies” [Journal of Manufacturing Processes, volume 132 (2024) 6070

Corrigendum to “Mitigation of distortion of Al/steel part under simulated paint baking condition: Experiment and numerical model studies” [Journal of Manufacturing Processes, volume 132 (2024) 6070

Numerical modeling and experimental study of thermal field and material removal for silicon wafer in final-touch polishing

Numerical modeling and experimental study of thermal field and material removal for silicon wafer in final-touch polishing

Unraveling the roles of jet streams on the unprecedented hot July in Western Europe in 2022

AbstractWestern Europe experienced an unprecedentedly hot July in 2022, which significantly impacted ecosystems and society. Our observational and numerical modeling study reveals that this event was influenced by anomalous North Atlantic and Eurasian jet streams. The northeastward shift of the North Atlantic jet stream, driven by sea surface temperature gradients, and the curving of the Eurasian jet stream, affected by rainfall anomalies in Pakistan, enhanced atmospheric subsidence over western Europe. This research highlights the crucial role of the synergistic behavior of the North Atlantic and Eurasian jet streams in driving extreme heat over Western Europe. Furthermore, CMIP6 climate model projections suggest that under the SSP585 scenario, similar jet stream configurations could lead to even more intense extreme temperatures (~7.02 ± 0.61 °C) compared to the current climatological mean.

Numerical modelling and simulation studies of laser beam heating parameters on depth of cut and surface temperature in laser-assisted machining of Ti6Al4V

Laser-assisted machining (LAM) is a hybrid machining process which uses a laser heat source to heat the narrow zone of a work part material ahead of the cutting tool. Surface temperature and heat-affected depth (effective depth of cut) achieved during localised laser heating play an important role in the machinability of the workpiece. In the current work, moving laser heat source simulation studies are performed using COMSOL Multiphysics software. The effect of laser power, beam diameter, scan speed, convective heat transfer coefficient and absorptivity are studied by simulating different test cases. Results show that the average maximum surface temperature increases when the laser power is increased from 100 W to 160 W by 55%. It increases with the increase in absorptivity from 0.3 to 0.39 by 18%. The average maximum surface temperature decreases when the laser diameter is increased from 1 to 2.5 mm by 46%. It decreases with the increase in scan speed from 50 to 200 mm/min by 5%. In the case of effective depth of cut, similar trends were observed with the variation of the above parameters. Further, the variation of convective heat transfer coefficient from 5 to 20 W/m-K does not affect the average maximum surface temperature and effective depth of cut. It was found that the laser power has a significant effect on average maximum surface temperature and effective depth of cut compared to other parameters.

Anisotropic Elastoplastic Behavior Formulation and Analysis of the Instability in the Large Deformations – A Numerical Modeling Study in Forming Processes

Anisotropic Elastoplastic Behavior Formulation and Analysis of the Instability in the Large Deformations – A Numerical Modeling Study in Forming Processes

Three-Dimensional Hydrodynamic Modelling to Estimate Sediment Rate in Lamong Bay

Abstract Lamong Bay Terminal, part of Tanjung Perak Port in Surabaya, functions as a container terminal. The port in the Surabaya area causes high ship traffic activity in the waters of Lamong Bay and sediment may be carried away from rivers heading towards the sea. The sedimentation process in waters can cause problems because it can cause shallowing of the waters, so it is necessary to maintain and monitor the depth of shipping lanes to maintain the safety of sea traffic. Therefore, understanding the hydrodynamics of seawater and sediment movement in the water region is necessary for successful dredging operations and assessing the impact of silt on port areas. In this research, the approach used to determine current patterns and sediment distribution was through the application of a numerical model with three– dimensional baroclinic hydrodynamic equations. The numerical modeling study in this research uses tidal data, sediment samples, salinity, and temperature to determine current patterns and the rate of sediment distribution. This process is carried out periodically and continuously as part of the evaluation of Lamong Bay Terminal. The results can serve as a reference for dredging planning to maintain the depth of the waters at the Lamong Bay Terminal. In this study, the highest current velocity was obtained at the time of spring tide reaching 0.9 ms−1 and at the neap tide of 0.4 ms−1. The sediment distribution pattern in the waters of Lamong Bay affected the existence of the pier and the morphological conditions of the seabed. The largest siltation or sedimentation that has occurred at Lamong Bay Port is 0.055 m/month near the jetty, thus depth monitoring is needed in this area, regularly. This study supports SDG 9 by advancing resilient infrastructure solutions to manage the sedimentation process in waters.

Predicting Salt Adsorption Capacity (SAC) and Membrane Fouling in Membrane Capacitive Deionization (MCDI) Using Machine Learning

Capacitive deionization (CDI) is an electrochemical technology that utilizes porous carbon electrodes to remove ionic substances. Ions from the solution are adsorbed during the charging stage and the adsorbed ions are desorbed during the discharging process, repeating the process to operate the system. To enhance ion removal capacity and prolong life of systems compared to CDI, membrane capacitive deionization (MCDI) has been developed. MCDI includes both anion and cation exchange membranes to induce the co-ion expulsion effects during the discharging stage, thereby exhibiting superior ion adsorption capacity than CDI. However, the utilization of ion exchange membranes causes a new issue of membrane fouling. Natural organic matter (NOM) serves as a common precursor to membrane fouling in nature environment. Especially, NOM could lead to the formation of fouling layers that disrupt transport phenomena across membrane systems, including ion exchange membranes used in MCDI. Numerous modeling studies have been conducted to investigate the effect of fouling on MCDI, aiming to predict fouling and evaluate the performance of MCDI in advance. Although a mathematical model was developed to predict MCDI performance under natural organic matter conditions, it had limitations of achieving high accuracy in natural environments. While a modified mathematical model showed high accuracy in predicting adsorption time reduction and capacity, it demonstrated low accuracy at points where current was applied and varied. This highlights the limitations of the modified mathematical model, as it is inadequate to consider the actual operating environment of MCDI. Therefore, this study adopted a robust machine learning model to address the limitations of the mathematical models. Electrochemical profiles and feed water conditions were used as input parameter of the model, enabling the prediction of both salt adsorption capacity and the growth of fouling layer on ion exchange membranes during operation. Consequently, this approach could improve the prediction accuracy of MCDI performance while providing detailed insights into fouling layer development, facilitating efficient operation and management of the MCDI system.

Predicting the Impact of Parameter Uncertainty on Model-Guided Li-O2 Cathode Design

Abstract Despite their high theoretical capacity, actual performance in lithium-oxygen (Li-O2) batteries is limited by sluggish transport and kinetic processes. Cathodes must provide ample surface area to host solid reduction products, but must also support species transport to access these surfaces. Numerous modeling studies therefore attempt to optimize cathode design by identifying microstructures to balance these two needs. However, model validation has historically relied on literature-sourced transport properties, which vary greatly between studies. In this work, we develop an open source, 1-D, continuum-scale Li-O2 battery model to examine the impact of electrolyte properties on predicted Li-O2 battery performance and design. Results demonstrate that O2 diffusion and solubility have the greatest impact on optimal design. Varying O2 diffusivity within the range of literature values surveyed led to maximum energy density variations of nearly 400%. These variations have a meaningful impact on the associated design conclusions: the optimal cathode porosity varied between 55 and 75%, depending on the O2 diffusivity. Moreover, the impact of advanced micrsotructures, such as graded cathode porosity, varies greatly with changes in electrolyte transport parameter estimates. As such, fundamental studies are required to accurately measure key electrolyte properties to enable numerical simulation as a guide to Li-O2 cathode design.

Peculiarities of flexural wave propagation in a notched bar

The results of numerical modeling and experimental studies of the propagation of flexural elastic waves in a metal notched bar approximates the effect of an acoustic black hole are presented. The sample is a bar with notches, the depth of which increases according to the power law with an exponent equal to (4/3). It has been confirmed experimentally and with the simulation results, that such bars slow down the propagation of an elastic wave to the end of the bar. It is shown in such structures flexural waves have dispersion and their localization at the end of the bar is higher for some natural frequencies than that of a solid rod. The natural oscillations of the whole and notched bars are compared, i.e. the shape of the amplitude of the flexural wave along the rods. The dependence of the flexural wave length in a notched bar on the frequency is investigated as a wave propagates to the end of the bar.

Evaluation of the Antecedent Saturation and Rainfall Conditions on the Slope Failure Mechanism Triggered by Rainfalls

The stability analysis of rainfall-induced slope failures considers a number of factors including the characteristics of the rainfall, vegetation, geometry of the slope, unsaturated soil characteristics, infiltration capacity, and saturation degree variations. Amongst all these factors, this study aims to investigate the effects of the antecedent rainfall and saturation conditions. A numerical modeling study was conducted using finite difference code software on a representative slope geometry with two different soil types. Two scenarios were followed: The first involved the application of three different rainfall intensities for varying initial saturation levels between 40% and 60%, representing the antecedent saturation conditions. The second scenario involved modeling successive rainfalls for a typical initial saturation degree of 50%. The impact of antecedent rainfall was assessed by determining the time required for failure during the application of a main extreme rainfall after a preceding rainfall of varying durations. Consequently, a zone of susceptible time for failure was suggested for use as a criterion in hazard management, allowing for the tracking of rainfall and its duration through the proposed chart for potential failures. Once the anticipated critical rainfall intensities have been determined through a meteorological analysis, a risk assessment for a specific slope can be conducted using the proposed practical procedure. Accordingly, a control mechanism may be established to detect the potential for a natural hazard. Furthermore, the proposed procedure was applied to a case study, whose modeling insights were in harmony with the real conditions of the slope failure. Thus, this demonstrated the significance of the antecedent conditions in modeling landslides triggered by rainfalls.

The physical and numerical modeling to design the breast wall spillway – AS case study

ABSTRACT The river systems in the Himalayan region exhibit year-round flow due to precipitation during the rainy season and snow/glacier melt in summer. These rivers carry massive sediment loads, especially during monsoons. Hydraulic engineers face the challenge of designing infrastructure capable of managing this sediment. Breast wall spillways are recommended for their ability to handle floodwaters and sediment disposal. The hydraulics of breast wall/orifice spillways changes with the varying reservoir level. The flow is free flow for reservoir water levels below the top of the sluice, whereas for higher water levels the flow is orifice flow. Orifice spillways are designed to pass water through openings or gates, where the flow is primarily governed by the hydraulic head and the orifice size. The flatter bottom profile helps in smoothly directing the flow through the opening without causing significant turbulence or separation, especially when the gate is partially open. Hence, the crest profile is flatter as compared to the overflow crest profile to avoid flow separation and negative pressures on the crest for small gate openings. Kwar Hydro Electric Project is one such Himalayan region project planned across the Chenab River in which a breast wall spillway has been provided to serve the dual-purpose of flood and sediment disposal. The present paper describes the physical and numerical hydraulic model studies conducted for Kwar H .E. Project, Jammu and Kashmir, to evolve a breast wall spillway profile, ski jump type energy dissipator at the toe of the spillway.

Enhancing Weather Forecast Accuracy Through the Integration of WRF and BP Neural Networks: A Novel Approach

AbstractIn the past century, scholars from both domestic and international communities have delved into the study of numerical weather prediction models to promptly understand meteorological factors and mitigate the impacts of extreme weather events on humanity. Effective and precise prediction models enable the forecasting of meteorological conditions in the upcoming days, empowering individuals to implement proactive measures to minimize the adverse effects of extreme weather (Liang et al., 2021). The WRF (Weather Research and Forecasting) modeling system is commonly used for forecasting meteorological elements. However, uncertainties terribly hamper the correctness of the forecasting results. To this end, the present study was conducted to build a secondary model on the basis of the WRF forecast model. The WRF‐BPNN model was proposed for verification after constructing the network, the temperature vertical profile and the mixing ratio vertical profile were predicted, and the results on the validation set were tested. The results showed that the WRF‐BPNN model could effectively predict the temperature profile and mixing ratio profile, presenting better performance than the traditional WRF model.

Investigating the influence of climate on the evolution of fold-and-thrust belts in Chinese Tianshan: A 2D doubly vergent numerical model approach

In most analogue and numerical modelling studies for investigating the evolutionary mechanisms of fold-and-thrust belts, the initial models are typically designed as “sandboxes” with one side fixed in the horizontal direction. However, such model setup has neglected the potential effects of drainage divide migration. To address this issue, in this study we developed a 2D doubly vergent numerical model that accounts for drainage divide migration to investigate the structural evolution in Tianshan fold-and-thrust belts since the late Cenozoic, with an emphasis on the influences of climatic forcing on rock deformation. The deformation styles of northern and southern Tianshan fold-and-thrust belts exhibit significant differences, with the northern Tianshan fold-and-thrust belt characterized by deep isoclinal anticlines, whereas the southern Tianshan fold-and-thrust belts are dominated by thrust faults and minor shallow-level tight anticlines. Our modelling results suggest that such differences in deformation style may be attributed to the north–south precipitation gradient across Tianshan mountain. The results also show that unilateral climatic perturbations can lead to migration of the drainage divides towards the side with lower precipitation, thereby impacting the structural evolution on the opposite side of the mountain range. Such impact mainly manifests as an increased tendency to develop more thrust faults in the direction toward which the drainage divide is shifting. This provides a new perspective for reevaluating the patterns of tectonic evolution in the global orogenic belts since the late Cenozoic.

Comprehensive Investigation of the Thermal Performance of an Electrically Heated Double-Glazed Window: A Theoretical and Experimental Approach

The thermal performance of windows is an important area of research to reduce the energy consumption of buildings and improve indoor comfort. The application of innovative glazing technologies can improve the energy performance of windows and transparent facades, resulting in significant energy savings. This paper presents research results on the energy performance of electrically heated windows. A comprehensive CFD and experimental analysis of the heat transfer processes in a window space depending on the size, power, and location of an electric heater was performed. The convective gas flows in the gas gaps and in the boundary layer were also analysed, and it is shown that a window with an electric heater can reduce the energy consumption of a room by 10–12%. This study is a pilot study to assess the feasibility and cost-effectiveness of electric local heating of a window or facade to minimise heat loss before full-scale implementation. The results of numerical modelling and experimental studies confirm the potential of the new technologies.

Exploring Porous Media for Compressed Air Energy Storage: Benefits, Challenges, and Technological Insights

The global transition to renewable energy sources such as wind and solar has created a critical need for effective energy storage solutions to manage their intermittency. This review focuses on compressed air energy storage (CAES) in porous media, particularly aquifers, evaluating its benefits, challenges, and technological advancements. Porous media-based CAES (PM-CAES) offers advantages, including lower costs and broader geographical availability compared to traditional methods. This review synthesizes recent advancements in numerical modeling, simulation, and experimental studies, which have enhanced the understanding of air–water–heat flow interactions and improved efficiency in these systems. Field studies demonstrate that using existing idle and abandoned wells can minimize infrastructure costs and environmental impact. This review underscores the potential of CAES in porous media to support the growing demand for sustainable and reliable energy storage solutions.

The Influence of Wind and Waves on Saltwater Intrusion in the Yangtze Estuary: A Numerical Modeling Study

The Influence of Wind and Waves on Saltwater Intrusion in the Yangtze Estuary: A Numerical Modeling Study

JUSTIFICATION OF THE DESIGN PARAMETERS OF THE SEED QUIET OF THE SOWING SECTION OF THE PNEUMATIC SEEDER

The problem of seed ejection from the furrow during sowing with the John Deere 90 Series planter can be solved by installing a seed firmer. However, factory seed firmers wear out quickly after treating 500–600 hectares. This indicates the need to improve the design and selection of materials for the firmers to ensure their durability. Further research and testing will help find optimal solutions to reduce wear and increase the efficiency of seed firmers. The goal is to conduct numerical modeling and laboratory studies of the oscillations of the seed firmer of the John Deere 90 Series pneumatic planter and to justify its design parameters and material selection. Using the Simcenter STAR-CCM+ software package, a simulation of the seed firmer's oscillation process, which is located between the press wheel and the soil, was carried out. As a result of the simulation, the distribution of the seed firmer's absolute deformation Δyf and stress σf in each cell of the created mesh was determined. The dependencies of the maximum stress value σfmax and the safety factor kf on the firmer's thickness Tf, the heel height Hf, and the distance of its placement relative to the free end of the firmer Lf for different materials (Nylon, ABS, TPU) were obtained. By solving a multi-criteria optimization problem, which reduces to the simultaneous search for optimal values of two criteria, the geometric parameters of the seed firmer were obtained: Tf = 6.5 mm, Hf = 12.4 mm, Lf = 14.6 mm. Based on laboratory studies, it was established that TPU should be chosen as the material for the seed firmer, as the least force (827 N) is required for its bending. This is confirmed by a lower safety factor kf.

EXPERIMENTAL STUDIES OF THE AIR HEAT EXCHANGER OF THE SIDE-EVAPORATION TYPE

Over the past two decades, many new devices based on renewable energy have been introduced for heating purposes: new heat recovery units, heat pumps, solar systems and many others However, no devices based on renewable energy sources have been widely applied in the field of cooling until now. This poses an important scientific challenge for researchers worldwide. A new solution that can solve the above-mentioned problems is direct and indirect air cooling through evaporation. Evaporative air coolers use the cooled heat of water evaporation to provide cooling and are less dependent on fossil fuels, they also feature a significantly higher conversion factor compared to mechanical compression systems. A higher transformation coefficient shows that the considered devices are able to reduce a significant part of the energy consumption used for air conditioning. One of the best methods for achieving very low temperatures with indirect evaporative air cooling is a new thermodynamic cycle known as the Maysotsenko cycle (M-cycle). Air heat exchangers of the indirect-evaporative type based on the Maisotsenko cycle have a higher transformation coefficient, so it is advisable to use them for cooling livestock premises. The creation of workable and cost-effective designs of air heat exchangers (heat utilizers) for livestock premises, which can be aggregated with a set of ventilation equipment, is a complex scientific and engineering task. According to the results of experimental studies of the indirect-evaporative type laboratory heat exchanger, the dependences of the temperature of the output primary air flow, the coefficient of thermal efficiency and effective cooling capacity on the temperature of the primary air flow at the inlet, its absolute humidity and its flow rate were obtained. Analyzing the obtained dependencies, it is possible to draw a conclusion about the correspondence between the results of numerical modeling and experimental studies, which is confirmed by the high value of the Pearson correlation coefficient (0.92–0.94). The optimal values of the factors under the condition of maximizing the effective cooling capacity NE = 426 W (different areas of the holes), NE = 380 W (the same areas of the holes) are tin = 32 °С, xin = 5 g/kg, Qin = 169 m3/h.