Numerical Simulation Tools Research Articles

Highly efficient (31%) of rubidium-based halide perovskite solar cell using SCAPS-1D simulation

Perovskite solar cells (PSCs) have emerged as potential substitutes to conventional photovoltaic devices due to their outstanding performance, affordability, and simplicity of construction. This study focuses on optimizing rubidium-based halide perovskite solar cells using numerical simulation tools, specifically SCAPS-1D (Solar Cell Capacitance Simulator), with rubidium germanium bromide (RbGeBr3) as the absorber material. The aim is to improve both efficiency and durability, addressing challenges in creating sustainable and cost-effective photovoltaic technologies. The performance of the proposed solar cell configuration was evaluated by examining various parameters such as the thickness of the absorber, the thickness of the electron transport layer and hole transport layer (HTL), defect densities, temperature, etc. Various hole transport layer materials, including Copper Barium Tin Sulfide (CBTS), Copper Iodide (CuI), PEDOT: PSS, and Spiro-MeOTAD, were analyzed to evaluate their impact on open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency. The findings indicate significant potential for RbGeBr3-based solar cells, with the CBTS HTL yielding the highest efficiency. Among the structures, the ITO/WS2/RbGeBr3/CBTS/Au structure was found to be optimal, achieving a power conversion efficiency of 31.48%, a current density of 26.27 mA/cm2, a voltage of 1.39 V, and a fill factor of 85.76%. This research provides valuable insights for designing and optimizing future perovskite solar cells, contributing to the advancement of renewable and sustainable energy technologies.

Efficiency Assessment of GaInp/GaAs Tandem Solar Cells: Analytical Investigation and Numerical Simulation

This paper presents a numerical simulation of a dual-junction tandem GaInp/GaAs cell made from top GaInp and bottom GaAs cells. For this purpose, we utilized a numerical simulation tool. Two methodologies were proposed, the first method consists of simulating each base layer cell of the top and bottom separately, and the second method simulated both layers in one file, to simulate both in one file. For improved electric characteristics of tandem solar cells, the current-match requirement between the top and bottom cells should be satisfied, necessitating the careful design of parameters. The top base GaInp layer thickness is adjusted to match this requirement. The solar spectrum reaching the lower cell is analytically calculated by subtracting the top cell spectrum from the total spectrum. the optimal value of short current density corresponds with a top cell base thickness of 0.8 µm, this results in an open circuit voltage of 2.45 V, a short circuit current of 15.7 Am/cm2, a fill factor of 91 %, an efficiency of 35 % for the first method and the second method used a script file designed to verify the above results and confirmed the values to be; 2.68 V open circuit voltage, 15.26 Am/cm², a short circuit current, 90 % fill factor, and 36.86 % efficiency under AM 1.5 G solar spectrum.

The influence of radiative heat transfer on flame propagation in dense iron-air aerosols

It is demonstrated that in the (near) zero-gravity experiments conducted by Tang et al. (Combust. Flame; 2009, 2011) iron powder aerosols created using the finest powders are optically thick, implying that radiative heat transfer between particles should not be neglected. To test this concept, an iron particle oxidation model has been implemented in OpenFOAM, including a coupling with the P1-model for radiative heat transfer.For flame simulations in which radiation is not included, obtained flame propagation velocities deviate less than 8% with results obtained using Chem1D-Fe and also show a good correspondance with algebraic models for optically thin aerosols. No significant difference in predicted flame propagation velocity is observed between 1D and 3D simulations: contrary to what is seen in gaseous flames, including the curvature of the flame does not increase predicted flame speeds substantially. However, measured flame propagation velocity values exceed numerically obtained predictions excluding thermal radiation by a factor of three to four. To the authors’ knowledge, this discrepancy is exemplary for the difference between experimentally obtained values for flame propagation velocities, and predictions made using numerical simulation tools neglecting radiative heat transfer.Accounting for radiation increases predicted flame propagation velocities, in the absence of confining boundaries, by approximately a factor of 10 which is in line with algebraic models for optically thick aerosols. In 3D simulations for the two finest iron powders in the experiments, including radiation and accounting for the presence of the confining tube wall results in an error of 11% and 35% with respect to measured flame propagation velocities, significantly smaller than predictions obtained excluding thermal radiation. Although these flames are not purely radiation-driven, inclusion of particle-to-particle radiative heat transfer enhances flame propagation velocities in simulations to values that correspond much better with experimental values than if radiation would not be taken into account.

NUMERICAL SIMULATION OF DOUBLE SKIN FACADES IN WINTER CLIMATES

The presented study reveals the analysis of the thermal behaviour of double skin facades (DSF) in winter conditions, using numerical simulation tools. The aim of the study is the development of a 3D simulation model, capable to evaluate the thermal behaviour of the modular elements in the DSF systems. This is essential requirement in the prediction and visualization of the facade’s thermal behaviour in the design stage and in the assessment of the real behaviour of such facade, when the specified modular elements are changed by the customer. The presented numerical simulation model aims to adequately reproduce the resulting set of thermal characteristics of the modular elements, to determine with sufficient accuracy their distribution in the real objects, implemented inthe models in DSF systems. An algorithm is developed in the study and graphical visualization of three models of double facade systems with and without DSF are analysed under winter conditions, using data from a meteorological station located in North-Eastern Bulgaria. A software product was used to represent the processes of heat and mass transfer, in which the corresponding boundary and initial conditions were set, based on which the results and analyses were obtained. The use of such numerical modelling is effective enough to predict the expected thermal behaviour of DSF systems. Thus, when selecting a DSF facade system, awareness of the thermal behaviour is ensured, and the financial efficiency of the project is more easily determined. Such a customized approach not only improves the sustainability and efficiency of buildings, but also satisfies the unique preferences and requirements of the customers.

Numerical simulation of individualized flow diversion cerebral aneurysms treatment

AbstractFlow diverter implantation has emerged as a highly effective treatment for cerebral aneurysms. However, the variability in patient‐specific vascular anatomy necessitates detailed pre‐operative planning to mitigate potential complications arising from standard, one‐size‐fits‐all devices. To address these challenges, robust predictive simulation tools are essential for optimizing flow diverter design and implantation strategies tailored to the unique characteristics of each patient's anatomy. This study focuses on developing an advanced numerical simulation tool for modeling the mechanical behavior of braided flow diverters during crimping and navigation through patient‐specific vasculature. Using isogeometric analysis (IGA) with NURBS‐based representations in LS‐Dyna, the intricate deformations of the flow diverter wires during catheter crimping are captured with high accuracy. The patient‐specific vessel geometries, derived from imaging data, are integrated into the model to account for variations in vascular structure, ensuring precise alignment and controlled navigation of the device. The navigation process relies on optimizing the central axis of the blood vessel to minimize torsional stress on the flow diverter, reducing the risk of device malfunction or failure during deployment. By incorporating patient‐specific information, such as vessel curvature and tortuosity, the simulation tool enables the prediction of potential issues, thus allowing for intervention planning that is tailored to individual anatomy. This patient‐specific approach enhances the safety and efficacy of flow diverter implantation and serves as a foundation for improved device design prior to prototype development.

Low-cost cascade thermoacoustic electric generator for energy harvesting

The cascade thermoacoustic heat engine has garnered significant attention for its ability to convert various heat sources into acoustic power without the challenges of acoustic streaming. By integrating it with a commercial loudspeaker, it can be further developed into a novel, low-cost thermoacoustic electric generator. This study aims to design and evaluate a thermoacoustic electric generator capable of producing several watts of electricity. The system consists of a cascade thermoacoustic engine, comprising a standing-wave and a traveling-wave unit, coupled with a B&C 6PS38 loudspeaker in a linear configuration. Atmospheric air is used as the working fluid, and standard market components, such as PVC and steel pipes, are proposed to minimize costs. Unlike traditional thermoacoustic generators, this system uses commercially available loudspeakers and a linear configuration, offering a cost-effective solution for low-wattage power generation, free from the issue of acoustic streaming. This makes it suitable for small-scale, distributed energy systems. The numerical simulation tool DeltaEC is employed to design and assess the system's performance. The optimal configuration is 4 m long, with the standing-wave and traveling-wave units centrally positioned. Operating at a frequency of 74.56 Hz, the system generates 90.18 W of electrical power with a total heat input of 1046.74 W and an external load resistance of 19.77 ohms. This corresponds to a heat-to-acoustic efficiency of 18.41 %, an acoustic-to-electric efficiency of 68.98 %, and an overall heat-to-electric efficiency of 8.62 %. The study also emphasizes the importance of operating conditions and impedance matching between the cascade engine and the loudspeaker. These findings represent progress toward developing an affordable thermoacoustic generator for energy recovery and other applications.

Debris flow simulations for hazard, vulnerability and risk assessment in the Karakorum mountain ranges, northern Pakistan

The Karakorum mountainous ranges in northern Pakistan have frequently witnessed devastating debris flows with damaging impacts on surrounding communities and infrastructure. Debris flow runout modeling and hazard assessment are crucial to develop and implement effective mitigation and adaptation measures. In this study, debris flow runout modeling using multiple scenarios of slope failures is carried out for hazard and risk assessments in the Karimabad watershed of the Hunza Valley in northern Pakistan. A 3D numerical simulation tool RAMMS was used to estimate the hazard intensity parameters (runout distance, flow velocity and height) along the debris flow track, based on the Voellmy model. To calibrate the model inputs, a back analysis of the Haiderabad stream debris flow event of July 26, 2022 has been conducted based on the estimated initial volume and the known runout distance. The calibrated values of the dry friction coefficient μ = 0.07 and turbulent coefficient ξ = 550 m/s2 were utilized for the three potential release areas. Different initial volumes were considered, and the results were combined to determine the debris flow runout distance and other intensity parameters for each scenario. The failure of three selected release areas could potentially block or divert the river Hunza. The integration of RAMMS parameters mainly flow velocity and height into hazard mapping assists in the demarcation of the area and elements at risk which are exposed to the potential impacts of debris flows. The derived debris flow hazard maps show that the road network including the KKH is exposed to debris flows. The impact of the debris flows on the surrounding communities and infrastructure is carried out through the vulnerability assessment and combined with the hazard assessment to derive the risk. Due to the intensive incision in the channels as the path for debris flow, the settlements and populations are less vulnerable to debris flow, however, poses a risk to the communication network and KKH. The study should assist the concerned agencies in developing and implementing debris flow risk mitigation strategies.

A Review of Simulation Tools for Thin-Film Solar Cells.

Unlike current silicon-based photovoltaic technology, the development of last-generation thin-film solar cells has been marked by groundbreaking advancements in new materials and novel structures to increase performance and lower costs. However, physically building each new proposal to evaluate the device's efficiency can involve unnecessary effort and time. Numerical simulation tools provide a solution by allowing researchers to predict and optimize solar cell performance without physical testing. This paper reviews thirteen of the main numerical simulation tools for thin-film solar cells, including SCAPS, AMPS, AFORS-HET, ASPIN3, GPVDM, SESAME, SILVACO, SENTAURUS, and ADEPT. This review evaluates each tool's features, modeling methods, numerical approaches, and application contexts. The findings reveal notable differences in material modeling, numerical accuracy, cost, and accessibility among the tools. Each tool's strengths and limitations in simulating thin-film solar cells are highlighted. This study emphasizes the necessity of selecting suitable simulation tools based on specific research requirements. It provides a comparative analysis to assist researchers in choosing the most effective software for optimizing thin-film solar cells, contributing to advancements in photovoltaic technology.

Penerapan Metode Runge-Kutta Orde 3 Untuk Penyelesaian Persamaan Diferensial Biasa

This research studies the application of the nth order Runge-kutta method as a numerical solution to ordinary differential equations. This method was chosen because it is able to provide high accuracy and flexibility in various PDB problems. We implement the nth-order Runge-Kutta algorithm in MATLAB and compare with other numerical methods, such as Euler's method. The results show that the nth order Runge-Kutta method is able to produce more accurate solutions, especially for nonlinear systems. This research makes a significant contribution to the development of numerical solutions for PDB and shows the potential of MATLAB as an effective tool for numerical simulation. Sensitivity analyzes of parameters and time steps were also performed to understand the impact of variations on stability and convergence.

High-order schemes of exponential time differencing for stiff systems with nondiagonal linear part

Exponential time differencing methods are a power tool for high-performance numerical simulation of computationally challenging problems in condensed matter physics, fluid dynamics, chemical and biological physics, where mathematical models often possess fast oscillating or decaying modes—in other words, are stiff systems. Practical implementation of these methods for the systems with nondiagonal linear part of equations is exacerbated by infeasibility of an analytical calculation of the exponential of a nondiagonal linear operator; in this case, the coefficients of the exponential time differencing scheme cannot be calculated analytically. We suggest an approach, where these coefficients are numerically calculated with auxiliary problems. We rewrite the high-order Runge–Kutta type schemes in terms of the solutions to these auxiliary problems and practically examine the accuracy and computational performance of these methods for a heterogeneous Cahn–Hilliard equation, a sixth-order spatial derivative equation governing pattern formation in the presence of an additional conservation law, and a Fokker–Planck equation governing macroscopic dynamics of a network of neurons.

Implementation of an experimental set-up for insertion loss measurements of sonic crystal acoustic screens

The use of metamaterials for the implementation of noise control devices in the context of environmental acoustics is a topic that has gained more and more attention in recent years. The complex design of such devices and the difficulty of their construction in real-world applications complicates the acquisition of experimental data related to their acoustical performance. Numerical simulation tools are used to simulate the behaviour of these novel noise control devices in their design phase and help to validate the designs by comparing them with experimental data. This data, usually acquired under controlled conditions, holds significant importance in confirming the increasingly precise numerical models that have been developed over the years to simulate the behaviour of these physical systems. In this paper, an experimental set-up that enables acquisition of acoustical performance data for a particular metamaterial-based noise control device, consisting of networks of isolated scatterers, is presented. This prototype possesses several distinctive characteristics that render it particularly interesting, including its adaptability, ease of use, speed of obtaining results, and, particularly, its economic viability in relation to the tests that can be conducted in an anechoic chamber.

Geometric optimization for localized attenuation of subsonic slit-based open acoustic barriers

In recent years, many solutions have been developed to reduce noise from different sources. One of these solutions is acoustic barriers. An acoustic barrier is a structure designed to reduce noise transmission between areas by blocking the direct path of sound. Open acoustic barriers are a valuable solution for technical and industrial plants. They allow airflow and visibility. Given the need for localized attenuation in these environments, it is possible to use numerical models to improve effectiveness and thus increase insertion loss in a region of interest. This study has used numerical simulation tools to provide degrees of freedom in placing the different elements of a subsonic slit-based open barrier. It has been shown that by rotating some of the elements and determining an area of interest, it is possible to improve the effectiveness of the barrier. These results allow using all the elements with the same topology to individually attack noise pollution problems in their location and frequency range.

9E heavy-duty gas turbine ammonia-hydrogen mixture combustion characteristics and NOx emission characteristics research

In this study, we used the numerical simulation tool FLUENT to numerically simulate the combustion of ammonia-hydrogen fuel in the combustion chamber of a 9E heavy-duty gas turbine, and analysed the effects of different hydrogen blending ratios on the stability of ammonia combustion and NOx emissions. We found that an increase in the hydrogen mixing ratio in the fuel during the ammonia-hydrogen mixture combustion process contributes to the reduction of NOx emissions and has a positive effect on combustion stability.

Numerical analysis of hybrid perovskite solar cells with NiOx and TiO2 as the charge transport layer

ABSTRACT This work exposits a hybrid perovskite-based solar cell consisting of NiOx as an electron-blocking material and TiO2 as a hole-blocking material to enhance its performance. Because the EBL material is critical to increasing efficiency and stability in a perovskite-based photovoltaic device, NiOx is being taken as a blocking material for improved reliability. It is also cost-effective and shows less hysteresis in contrast with alternative EBL materials. In addition, a wide band gap material like TiO2 as HBL is considered for enhancing carrier transportation phenomena that improve device performance. The efficiency of the suggested photovoltaic device is assessed in terms of solar parameters using the TCAD numerical simulation tool, accounting for the impacts of the thickness of the perovskite material, the density of defects, and the blocking material doping concentration. Also, the temperature reliability study is thoroughly investigated, considering all the optimised thicknesses of different layers and their optimised doping level.

Application of Numerical Modeling and Finite Element Analysis in Fused Filament Fabrication: A Review.

Additive manufacturing (AM) is not necessarily a new process but an advanced method for manufacturing complex three-dimensional (3D) parts. Among the several advantages of AM are the affordable cost, capability of building objects with complex structures for small-batch production, and raw material versatility. There are several sub-categories of AM, among which is fused filament fabrication (FFF), also commonly known as fused deposition modeling (FDM). FFF has been one of the most widely used additive manufacturing techniques due to its cost-efficiency, simplicity, and widespread availability. The FFF process is mainly used to create 3D parts made of thermoplastic polymers, and complex physical phenomena such as melt flow, heat transfer, solidification, crystallization, etc. are involved in the FFF process. Different techniques have been developed and employed to analyze these phenomena, including experimental, analytical, numerical, and finite element analysis (FEA). This study specifically aims to provide a comprehensive review of the developed numerical models and simulation tools used to analyze melt flow behavior, heat transfer, crystallization and solidification kinetics, structural analysis, and the material characterization of polymeric components in the FFF process. The strengths and weaknesses of these numerical models are discussed, simplifications and assumptions are highlighted, and an outlook on future work in the numerical modeling and FE simulation of FFF is provided.

Factor of safety analysis for mine pillar considering the influence of the intermediate principal stress component

Failure of mine pillars, especially in deep underground mines, significantly threatens the safety of miners and equipment. Previous studies on mine pillar stability design have used classical constitutive models that ignore the intermediate principal stress component when determining the factor of safety. In this study, we develop and implement a three-dimensional modified Hoek–Brown (HB) constitutive model that incorporates the intermediate principal stress component into the numerical simulation tool FLAC3D. Furthermore, we propose and apply a strength-reduction technique to determine a more accurate factor of safety for mine pillars. This novel approach provides a more comprehensive and realistic method for geomechanical analysis and pillar design, enhancing our understanding of pillar stability. Through numerical analysis, we illustrate the impact of the intermediate principal stress component on mine pillar plasticity. The factor of safety is calculated via the strength reduction method, revealing a substantial improvement from 1.7 with the classical HB model to 2.0 with the 3D HB model. Including the intermediate principal stress component reduces the evolution of plasticity in the mine pillar. For instance, the volume of plastic zones diminishes, and the factor of safety increases as the width-to-height ratio increases. Exemplary simulations show that ignoring the effect of the intermediate principal stress component, including underestimating safety levels, designing suboptimal pillar design, and misinterpreting in situ observations and measurements, can lead to severe consequences.

Sensor-based modelling of suction sails to integrate into a numerical simulation tool for a wind-assisted vessel and its application to green shipping

In order to achieve reductions in ship emissions and operational costs while complying with increasingly stringent regulations, ship owners need to consider combining multiple efficiency enhancing strategies where synergistic benefits are possible. One such option is to couple wind assistance with speed reduction. Realizing this solution’s maximum potential requires both an experimental characterization of the forces present when the vessel is sailing as well as a numerical tool to analyse instantaneous energy consumption at specific conditions to suggest optimal operating strategies over a route. Therefore, this paper focuses on processing strain gauge measurements for real-world wind propulsion units, coupled with a numerical modelling tool for a wind-assisted container vessel. These measurements are then integrated into the numerical model and simulations are conducted to suggest improved operating strategies for increased fuel efficiency of a vessel across different speeds and along a route while considering real-world wind conditions. The results suggest that an increased travel time through speed reduction of approximately 8% can result in a fuel consumption decrease of nearly 16% due to the reduction in ship resistance and the increasing share of propulsive thrust provided by wind-assistance.

Numerical Investigation on Two-Phase Flow-Electrochemical Reaction Coupling in PEM Water Electrolyzers Porous Transport Layer Under High Operating Pressures

Proton exchange membrane water electrolyzers (PEMWEs) operated at high pressures have advantages such as lower energy consumption, reduced noise, and absence of component slippage. They have a more robust potential for commercial applications than other electrolyzers. The transport characteristics of two-phase flow within the porous transport layer (PTL) and channels are not well understood, especially under high-pressure conditions. The gas bubbles generated in the catalyst layer (CL) pass through the PTL and reach the flow channel. However, oxygen evolution reaction in the anode CL may be limited if these bubbles block the pathway of liquid water, causing reactant starvation. The interaction between electrochemical reactions and gas bubbles thus directly impacts a PEMWE's efficiency. This study aims to investigate the coupling between the two-phase flow and electrochemical reactions under high-pressure conditions.A two-dimensional (2D) CFD model was developed to simulate the bubbly flow through a reconstructed PTL. The volume of fluid (VOF) method was employed to capture bubble growth, movement, and detachment, as illustrated in Figure 1. The coupling of bubble transport and electrochemical reactions was achieved through the application of a weighted averaging method. A cross-section of a stochastically reconstructed titanium felt model was generated as the computational domain; see Fig. 1(a). The computation domain consists of a liquid water channel, a PTL, and a simplified CL interface at the bottom. The CL's reaction rate is modeled as a function of local bubble coverage on the CL interface. Transient simulations of the two-phase flow of the PEMWE anode side were carried out for pressures ranging from 1 bar to 200 bar. The simulation results elucidate the flow characteristics of liquid water in the PTL under high-pressure conditions and quantitatively reveal the coupling between two-phase flow and electrochemical reactions. The behavior of the two-phase flow in PEMWE is found to be sensitive to operating pressure. As the operating pressure increases, the size of bubbles generated on the CL interface decreases, resulting in a higher permeability of liquid water than that under low pressures. When the flow rate of liquid water in the channel is sufficiently high, bubbles do not fully develop and are rapidly removed from the domain. This phenomenon significantly shifts the two-phase flow regime within the channels,. Furthermore, the activation overpotential is substantially reduced under high-pressure conditions. The present study demonstrates a numerical simulation tool for high-pressure PEMWE. A future study of a full 3D PTL model is currently underway. Figure 1

Critical review on resource scheduling in IaaS clouds: Taxonomy, issues, challenges, and future directions

AbstractIn a cloud computing environment, the primary goal of resource scheduling is to reduce the economic expenditures for cloud users and grow fiscal achievement for cloud providers. In this article, the study of numerous forms of resource scheduling algorithms is presented that has been applied in IaaS clouds. The selected research articles are classified into six categories, according to the nature of the algorithm used. Further, the authors pointed out several issues and challenges with the help of the resource scheduling algorithms, the comparative performance metrics, and the simulation tools used to validate the several algorithms. The enhancement illustrates better performance concerns decreasing the cost and time while improving the competence and utilization of resources for IaaS clouds. These algorithms are executed in numerous simulation tools and real environments similar to CloudSim, SimGrid, MATLAB, and test‐bed environments (practical implementation). This critical review and classification will serve as a foundation for further research in IaaS clouds in the Internet of Things (IoT) environments.

Unveiling thermo‐fluid dynamic phenomena in laser beam welding

AbstractLaser beam welding (LBW), as a non‐contact process with short cycle times and small heat affected zone, is a key technology for automated metal fabrication. Despite its efficiency, the susceptibility of certain alloys to solidification cracks remains a significant challenge. These cracks emerge in the transition zone between liquid and solid phases during the solidification process. Thermo‐fluid dynamic processes within the melt pool play a crucial role in solidification crack formation during LBW, influencing heat distribution, mass transport, and consequently, the microstructure and mechanical properties of the weld. An in‐depth exploration of thermo‐fluid dynamics within the melt pool, contributes to an improved understanding of the correlations between process parameters and melt pool flow aiming to avoid solidification cracks. Therefore, in situ process investigations were conducted at beamline P07 of PETRA III at the German Electron and Synchrotron (DESY). 1.4404 stainless steel specimen containing an 5 wt.% of tungsten particles, serving as tracer, were additively manufactured using laser powder bed fusion. The tungsten particles are evenly distributed within the samples. High‐speed synchrotron x‐ray imaging of the process zone allowed for detailed in situ analyses. Leveraging the lower x‐ray absorption coefficients of the base steel material compared to tungsten, the particles appeared as dark dots in the images. The experimental setup involved blind welds on the samples, where a portion of the sample was melted by the laser beam, forming a molten pool in the center while the edges remained intact. The uniform distribution of the particles in the sample means that the movement of the particles in the molten pool is overlaid by static particles located in the unmelted edges of the sample. To enhance the observation and tracking of particle movement within the melt pool, the image contrast was optimized, and static particles were filtered out. The resulting images offer a visual representation of thermo‐fluid dynamical flows during LBW, based on the movement of tracer particles. Analysis was performed using an on Hessian blob detection and Kalman filter based tracking tool [1]. The results of this investigation provide valuable insights into the intricacies of thermo‐fluid dynamics during LBW, offering a foundation for the advancement of numerical modeling and simulation tools in the field of LBW.