Simulation Software Research Articles

Temperature distribution in the PGAA system: Collimator, shutter, and filter in TRIGA Mark II reactor

This article examines the impact of temperature on the steel collimator cap and the primary beam shutter. These components will be used to implement the Prompt Gamma Activation Analysis (PGAA) technique in the Moroccan TRIGA Mark-II research reactor. The steel collimator plug is essential for forming the neutron beam, while the main role of the shutter is to stop the beam when the channel is inactive. This study analyzes the effect of temperature on the collimator and shutter system, particularly focusing on the variation in maximum temperature over a month of operation with 8-h cycles per day, the behavior of temperature over 24 h, the total heat flux as a function of the length of the experimental device, the temperature distribution in mild steel (E235) and 304L stainless steel materials, and the total displacement and strain gradient as a function of temperature. All calculations were performed using COMSOL Multiphysics simulation software, based on the finite element method.

Analysis of Central Warehouse Location and Logistics Distribution Land and Sea Modes

Distribution Center Warehouse has a very important role in logistics process and selecting the most strategic location is a must. Strategic location in Bali Province will give certain advantage to logistics company with travelling time as a point of view. Industrial Revolution 4.0 enable us finding such location with the help of computer simulation software such as AnyLogic. This research use AnyLogic capability to compare travelling time for 2 case of Distribution Center Warehouse: Mangupura and Negara. This comparison takes into account logistic process of delivering goods to Bali Province via sea transport (Gilimanuk Port). Result shows that Distribution Center Warehouse in Negara has an advantage compare to Mangupura in term of travelling time.

3D Modelling and Simulation Based on Kinematic Analysis for Hippotherapy

The engineering perspective on the physiology and anatomy of living things has led to the emergence of the science of biomechanics. Developing computer technologies have made it possible to examine the behaviour of living things in more detail and to develop technologies that enable kinetic and kinematic analysis of movements to imitate real limbs. In this study, the natural gaits of horses (Walk, Canter and Trot) were analysed with image processing techniques, kinematic analyses were made and three-dimensional solid models were created. Giving movement ability to the extracted solid models was carried out with the simulation software prepared on the Matlab-SimMechanic platform. By comparing the findings obtained as a result of image processing and simulation, the success of transferring the movements to a developed system was evaluated. After mathematical equations were created in the MATLAB environment, the equations were tested on the developed system and their performance rates were determined. With the developed system, joint angles, ability to reach the correct position and movement ability were analysed and it was shown how the mathematical equations required to perform the movements could be derived. As a result, a design process model for movement analysis, simulation and control of different living groups is presented with the equations obtained by formulating the information obtained from the developed system.

Framework for Designing of Wireless Sensor Network Using OPNET and Effect of Transport Protocols on Simulation

A Wireless sensor network can be defined as a network of devices that can communicate the information gathered from a monitored field through wireless links. The data is forwarded through multiple nodes, and with a gateway, the data is connected to other networks like wireless Ethernet. It is intended for a general application and should be able to collect data from many nodes, every node connected to several sensors. One possible application for such a network is in the medical area. At first the network will be used to display the evolution of blood pressure; the body temperature, the ambient temperature and pressure and the level of the transfusion liquid can be collected as well. The network coordinator will transmit the data to a local server for further processing. The simulation will be used to evaluate the general parameters of the wireless network and to optimize it. In this paper, we aim to evaluate the performance of a ZigBee wireless sensor network using OPNET and also study the effects of TCP and UDP on the performance of the application based on OPNET simulation software. Keywords-Sensor, wireless sensor network, ZigBee, OPNET, TCP, UDP.

Effect of Nb and B on the Precipitation Behaviors in Al-Ti-Nb Balanced-Ratio Ni-Based Superalloy: A Phase-Field Study

In this paper, quantitative two-dimensional (2-D) phase-field simulations were performed to gain insight into the effects of B and Nb for Al-Ti-Nb balanced-ratio GH4742 alloys. The microstructure evolution during the precipitation process was simulated using the MICRESS (MICRostructure Evolution Simulation Software) package developed in the formalism of the multi-phase field model. The coupling to CALPHAD (CALculation of PHAse Diagram) thermodynamic databases was realized via the TQ interface. The morphological evolution, concentration distribution, and thermodynamic properties were extensively analyzed. It is indicated that a higher Nb content contributes to a faster precipitation rate and higher amounts and the smaller precipitate size of the γ′ phase, contributing to better mechanical properties. The segregation of the W element in γ′ precipitate due to its sluggish diffusion effect has also been observed. Higher temperatures and lower B contents accelerate the dissolution of boride and reduce the precipitation of borides. With the increased addition of B, the formation of borides may have a pinning effect on the grain boundary to hinder the kinetic process. In addition, borides are prone to precipitate around the interface rather than in the bulk phase. Once the M3B2 borides nucleate, they grow in the consumption of γ′ phases.

Lower Back & Comfortability Analysis of Driving Posture to Mitigate Musculoskeletal Disorders: An Ergonomics Study using Digital Human Modelling in JACK Software

In this paper, the crucial aspect of driver comfort was explored by investigating the prevailing driving postures among individuals, aiming to discern their ergonomic implications and ascertain whether the commonly adopted postures are conducive to musculoskeletal health or pose potential risks. From the last decade vehicle like cars have become one of the common modes of personal transport. Car has high relevance in day-to-day activities like commuting, economic activities and sports etc. The continuous driving of vehicle can lead the driver prone to musculoskeletal disorders such as back pain, spine injury and posture issues. This study is conducted to address the ergonomic aspects of posture of the driver to highlight the risk of Musculoskeletal disorders (MSDs) and to optimize the driving posture. Lower Back Analysis (LBA) and Comfortability Analysis is performed in JACK Software to analyze the driving posture. A DHM (Digital Human Model) is created in JACK Simulation Software according to the collected anthropometric data of an average Pakistani man. A virtual Environment is created in JACK Simulation Software. The posture of the subject is analyzed by taking measurements of the subject’s angle of joints when they are sitting in a driving posture. For Ergonomic Analysis the Driving Posture is evaluated on JACK software to Mitigate Musculoskeletal Disorders. Results show that the subject is having low back compression force of 672 which is below the NIOSH Back Compression Action Limit of 3400N representing a nominal risk of low back injury.

Simulation of Acoustic Conditions within the Markanda Temple, India

The ancient religious structures hold a significant wealth of knowledge, with their acoustics being a part of theirinheritance. Hindu temples in Central India built during the 12th century exemplify this. However, the challenge lies inevaluating the acoustics under occupied conditions due to the various configurations of sound sources andworshippers' positions. While existing literature offers calculation methods for predicting reverberation time, thispaper introduces a novel and intriguing approach. We simulate the acoustics in the pavilion and sanctum space underoccupied conditions using the advanced acoustics simulations software ‘ODEON’. This innovative method allows us toobtain a comprehensive set of acoustic parameters. Due to its reverberant nature, the study examines the Markandatemple in Gadchiroli district, allowing for a better understanding of occupancy-related variations. Nevertheless, theresults indicate that the impact of occupancy was limited due to the absorbing elements on the floor in the form ofcarpet, resulting in ‘fair’ acoustic conditions for speech intelligibility.

Thermal characteristics of gasoline engine powered by petrol and LPG under variable speed, compression ratio

ABSTRACT This study involves the evaluation of the thermal characteristics of gasoline engines fuelled with LPG instead of gasoline fuel using the simulation software Diesel-RK. The feasibility of using LPG is investigated via parameters (combustion, performance, and emissions) at different engine speeds and compression ratios. A two-zone combustion model is used. The results revealed that the maximum pressure obtained was 82 bar for gasoline compared to 78 bar for LPG at 5000 rpm. There is a noticeable reduction in BSFC with the use of LPG relative to gasoline for all ranges of compression ratio and engine speed used. The NOx emissions were significantly reduced by 8.60% using LPG rather than gasoline. Studies conducted by different researchers validate the obtained results.

Numerical and experimental investigations of swirl-stabilized partially premixed flames using natural gas-hydrogen-air mixtures

This study uses experimental and numerical techniques to examine natural gas and hydrogen mixtures as fuel with a partially premixed swirl-stabilized burner. Variations in the fuel mixture composition were investigated throughout the course of the study. In the experiments, hydrogen was gradually added to the fuel combination, initially made only of natural gas. Chemiluminescence imaging was used to examine how the addition of hydrogen affected the stability and overall structure of the flame. Throughout the experiments, the overall volumetric fuel flow rate remained constant. The change to the flame stabilization mode from a detached flame to a burner attached flame only happened once a certain volumetric hydrogen ratio (H2VOL%) in the fuel was attained. Numerical simulations also evaluated how the lifted flame dimensions and stabilization method changed. The simulations are performed using a commercial compressible, finite volume Large Eddy Simulation software and include the Thickened Flame Model (TFM) for turbulence-chemistry interactions, the Flamelet Generated Manifold (FGM) combustion model, and the Large Eddy Simulation (LES) turbulence model. Experimental and numerical results show that the flame lowers and becomes more compact as the H2VOL% increases. Additionally, experimental and numerical data showed that the flame stabilization mode changes for H2VOL% approaching the value of 70%.

Analisis Pengaruh Suhu Terhadap Nilai Konduktivitas Pada Perpindahan Panas Secara Konduksi Menggunakan Virtual Lab Amrita

This study aims to determine the effect of temperature value on conductivity value (conduction heat rate) in conduction heat transfer. The method used in this research is an experimental method with variable temperature and variable conductivity values of materials using amrita virtual lab simulation software. The variable variation used in this study is the difference in materials using cardboard and glass with variations in voltage, current, diameter and thickness of the same material. The results of this study indicate the effect of temperature on the conductivity value, if the conductivity value of a material is small then the temperature will be large because this experiment was conducted on insulating materials on both objects. Temperature will inhibit heat transfer by conduction, it can be concluded that both materials are good heat insulators. Keywords: Conduction heat transfer, Temperature, vlab Amrita.

Improving the power conversion efficiency of RbPbBr3 absorber based solar cells through the variation of efficient hole transport layers

Novel rubidium-lead-bromide (RbPbBr3) hybrid perovskite solar cells (HPSCs) are gaining attention from researchers because of their exceptional semiconductor qualities. Researchers have been examining RbPbBr3-based single junction photovoltaic cells in a number of configurations, including two different hole transport layers (HTL) made of V2O5 and MoTe2 and an electron transport layer (ETL) made of CdS. We investigated elements including band alignment, defect density, layer thickness, doping concentration, interface defect density, carrier concentration, generation, recombination, open circuit voltage (VOC), short circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE) through extensive numerical analysis using SCAPS-1D simulation software. According to the research, the V2O5 HTL design, with a VOC of 1.1433 V, a JSC of 34.3969 mAcm−2, and an FF of 86.63 %, attained the maximum PCE at 34.06 %. By contrast, the MoTe2 HTL configuration's PCE was 31.66 %, with a VOC of 1.0388 V, a JSC of 34.4977 mAcm−2, and an FF of 88.35 %. These results provide insightful information and a workable strategy for creating RbPbBr3-based, reasonably priced thin-film solar cells.

Intelligent planning of fire evacuation routes in buildings based on improved adaptive ant colony algorithm

Intelligent planning of fire evacuation routes is an important guarantee for rapid emergency response. Ant colony optimization, as an intelligent bionic algorithm, has notable advantages in route planning. However, traditional ant colony optimization corresponds to a low convergence rate, is easily caught in local optimal solution, and regards route length as the only constraint. To resolve these problems, an improved adaptive ant colony optimization (IAACO) algorithm was proposed in this study. Risk, energy consumption, and route length were taken as key factors to improve the heuristic function, optimize the pheromone update function, and establish multi-objective constraints, The standards for fire evacuation better align with practical requirements. Meanwhile, the adaptive pheromone volatile coefficient was introduced to balance convergence and global searching ability. In addition, the hazard range on the grid map was visualized. The results indicate that under various complex obstacle grid maps, the path inferiority of IAACO is reduced by 61.7% and 58.4%, 43.6% and 36.7%, and 41.6% and 67.7% compared to ACO and IACO, respectively; under the condition of multiple exits, the inferiority is reduced by 63.8% and 54.6%; under the condition of multiple fire sources, the inferiority is reduced by 40.1% and 34.6%; compared with other algorithms, IAACO shows the lowest path inferiority index, 26.6. IAACO is applicable to both the dynamic planning of fire evacuation routes and the evacuation simulation software, Pathfinder, and it performs better than the built-in algorithms of Pathfinder. Facts have proved that the IAACO algorithm significantly improves the safety level of evacuation compared to traditional evacuation methods and other optimization algorithms.

Dynamic Response Analysis of Moving Trains Passing Through the Stationary Thunderstorm Downburst Wind

The safety of the high-speed train traveling through the stationary thunderstorm downburst wind was studied. First, a thunderstorm wind test device was used to simulate the stationary thunderstorm downburst wind. Based on the rigid model pressure measurement tests, the aerodynamic forces of the train traveling along different paths through the stationary thunderstorm downburst wind were measured. The influence of the radial distance of the crossing path on the aerodynamic force coefficients of the train was investigated. On this basis, an unsteady aerodynamic model of the high-speed train crossing through the stationary thunderstorm downburst wind was established, and dynamic response analysis was carried out using the SIMPACK multibody dynamics simulation software to explore further the safety of the high-speed train crossing through the stationary thunderstorm downburst wind. The research showed that the stationary thunderstorm downburst wind field has significant spatial variation characteristics compared with the atmospheric boundary layer wind field. When the train passes through the thunderstorm downburst wind, the radial wind speed and wind yaw angle experienced by the train constantly change, and the change curve shows a symmetrical distribution. The aerodynamic force of the train will undergo sudden loading and unloading processes, and the lateral force coefficient of the train on different paths shows a “pulse-type” variation. Moreover, the lateral force coefficient increases with the increase of wind yaw angle. Under the influence of the thunderstorm downburst wind, the variation trend of the aerodynamic force coefficients of the train is consistent with that under crosswind. However, there are significant differences in the numerical values. Therefore, it is impossible to simply use the formula for calculating the aerodynamic force coefficients of the train under crosswinds to predict the aerodynamic force coefficients of the train under the thunderstorm downburst wind. While passing through the thunderstorm downburst wind, the overturning coefficient index plays a decisive role in the safety of train operations. Train rollover is the main form of train safety accidents, while derailment accidents are not easy. The numerical results obtained in this study are significant for evaluating the operational safety while moving trains traversing the stationary thunderstorm downburst wind.

Numerical simulation and safety assessment of fires in historic timber structures based on fire load investigation

Historic timber structures face substantial fire loads and complex fire risks. Subsequent renovations and utilization may influence their fire safety performance. Therefore, accurately predicting indoor fire development in historic buildings and assessing their fire safety performance is crucial. Numerical fire simulation is currently at the forefront of analyzing and assessing fire risks in historic buildings. However, there is a shortage of globally accessible historic building fire data. This paper proposes a method to determine fire scenarios, peak heat release rates, and development curves of indoor fires in wooden historic buildings through a fire load investigation. Using the Guangzhou ancestral hall as an example, PyroSim fire dynamics simulation software is employed to calculate fire development and assess the available safe evacuation time. The simulation results are subsequently input into the Pathfinder evacuation simulation software to ascertain the required safe evacuation time for indoor occupants. A comparative assessment is conducted to evaluate the fire safety performance before and after the renovation of historic buildings. The research findings indicate that installing closed glass curtain walls in the courtyards of ancestral hall buildings in Guangzhou accelerates the infiltration of smoke during fires, leading to rapid fire spread and long-distance ignition, significantly reducing the time available for safe evacuation. Therefore, when renovating and utilizing the ancestral hall buildings in Guangzhou, the installation of ventilation and smoke extraction systems should be prioritized to slow down fire development. Additionally, controlling the number of indoor occupants is an effective management measure to mitigate fire damage in historic buildings.

A MODELING OF RF PROPAGATION FOR LOW FREQUENCY IN NATURAL CAVES WITH 3D MODEL SIMULATION

The study of the RF propagation model within natural caves remains challenging. In the past, the propagation model in the tunnel was compared using waveguide theory because of the electrical conductivity of tunnel walls. However, waveguide models have limitations because a cut-off frequency from the tunnel dimension does not allow frequencies lower than the cut-off frequency to propagate. Although the frequency wave lower than the cut-off frequency cannot theoretically propagate, in practice, it can propagate through the cave. Therefore, this paper presents the modelling of RF propagation at low frequencies in natural caves using empirical methods by measuring the waves propagated within cave passages at the Chiang Dao Cave (limestone) and the Patihan Cave (sandstone). The measurement will focus on analyzing and comparing factors, propagation mechanisms, and behavior, which cover the frequencies at 300, 1000, 1650, 2325, and 3000 kHz, to develop the low-frequency attenuation model within the cave proposed in this paper. The 3D cave models obtained from a LiDAR scanner were used to calculate the physical factors of the cave walls, and then the path losses were calculated using our proposed model and compared to the experimental results. In addition, the path losses calculated using 1) CST simulation software and 2) the waveguide model were also compared with the results from the proposed model. The results obtained from the proposed model provide attenuation values similar to those of the experimental results. Finally, the concept of the low-frequency attenuation model can be used for the prediction and analysis of the propagation performance of low-frequency waves in caves, tunnels, or underground mines and lead to the development of cave communication technology and electromagnetic knowledge in the future.

No Pain, No Gain—Giving Real-Time Emotional Feedback in a Virtual Mirror Improves Collaboration in Virtual Teamwork

This study investigates the impact of real-time emotional feedback on the quality of teamwork conducted over videoconferencing. We developed a framework that provides real-time feedback through a virtual mirror based on facial and voice emotion recognition. In an experiment with 28 teams (84 participants), teams collaborated over Zoom (version 5.16.6) to set up a virtual Mars station using custom simulation software (Mars Star City, version 4.0). Participants were divided into 14 experimental teams, which were shown the virtual mirror, and 14 control teams without it. Team performance was measured by the improvement in the Mars simulation output quality. Our analysis using correlation, multi-level regression, and machine learning revealed that fewer interruptions but an increasing number over time correlated with higher performance. Higher vocal arousal and happiness also enhanced performance. We confirmed that female presence in teams boosts performance. SHAP values indicated that high variability in happiness, head movement, and positive facial valence—an “emotional rollercoaster”—positively predicted team performance. The experimental group outperformed the control group, suggesting that virtual mirroring improves virtual teamwork and that interrupting each other more while speaking less, leads to better results.

Numerical analysis of a single channel exposed core elliptical shaped PCF based highly sensitive SPR sensor for wide RI sensing

This study presents a numerical study of a highly sensitive photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor capable of detecting five types of cancer and bacterial contamination in water. By precisely arranging only two air holes in a single channel of an elliptical-shaped PCF, the sensor maximizes interaction between core-guided modes and surface plasmon polaritons (SPP) along the fiber. Evaluation using COMSOL Multiphysics simulation software, based on finite element method (FEM), demonstrates outstanding sensor performance across a wide refractive index (RI) range (1.33 to 1.43). With a maximum wavelength sensitivity (WS) of 188,000 nm/RIU and amplitude sensitivity (AS) of -22,377.99 RIU−1, the sensor achieveStructural Design and Methodologys a sensor resolution (SR) of 5.3191 × 10−7 RIU and figure of merit (FOM) of 854.55 RIU−1. Notably, it exhibits AS and WS values tailored for specific cancer cell types and water contamination. These results endorse the sensor’s potential in diverse biological and molecular analyte RI detection applications within the visible to near-infrared (VNIR) range (0.55 to 4 µm), offering high sensitivity, affordability, wide sensing range, good linearity, low propagation loss, and simplicity in construction.

Dynamics and Implementation of FPGA for Memristor-Coupled Fractional-Order Hopfield Neural Networks

The coupling between neurons can lead to diverse neural network architectures, with the Hopfield neural network (HNN) being particularly noteworthy for its resemblance to human brain function and its potential in modeling chaotic systems. This paper introduces a novel approach: a fractional-order HNN coupled with a hyperbolic tangent-type memristor. Initially, we propose a new model for the hyperbolic tangent-type memristor and fingerprints. Subsequently, we construct a memristor-coupled fractional-order Hopfield neural network (mFOHNN) and explore its dynamic behavior using various analytical tools, including phase diagrams, bifurcation diagrams, Lyapunov exponent diagrams, Poincaré maps, and attractor basins. Our findings reveal rich coexisting bifurcation behavior in the neural network model, influenced by different initial values of coexisting attractors. Finally, we validate the model through analysis and implementation using Multisim circuit simulation software and FPGA hardware, respectively.

Design of high gain MMIC amplifier for LEO satellite communication systems

In this paper, we present a novel design of S-band monolithic microwave integrated circuit (MMIC) amplifier based on GaAs Mesfet HFET-1102 transistor used in radiofrequency (RF) and microwave communications system. Basing on Chebyshev gain response an analytical method is used to design two stages lumped microwave amplifier. The matching networks constituted by lumped elements are transformed to T inductive networks and the resulting amplifier is optimized using RF simulator software. Thelumped optimized amplifier is then transformed to distributed amplifier and implemented on Rogers TMM3 substrate, largely used in microwave circuits. The proposed MMIC distributed amplifier is stable in the frequency band (2–4 GHz) and excellent performances are obtained in terms of very high gain reaching a peak of 34.23 dB, minimum input return loss (S11) of −8.85 dB at f=2.62 GHz, minimum output return loss (S22) of −12.21 dB at f=2.05 GHz and very good output/input isolation (S12) lower than −51.99 dB. For its excellent performances, the proposed MMIC distributed amplifier, is very suitable for use in space telecommunications as in Low Earth Orbit (LEO) satellites onboard receivers where the high gain amplifier is very important to assure the success of the space missions.

LUNAR: Automated Input Generation and Analysis for Reactive LAMMPS Simulations.

Generating simulation-ready molecular models for the LAMMPS molecular dynamics (MD) simulation software package is a difficult task and impedes the more widespread and efficient use of MD in materials design and development. Fixed-bond force fields generally require manual assignment of atom types, bonded interactions, charges, and simulation domain sizes. A new LAMMPS pre- and postprocessing toolkit (LUNAR) is presented that efficiently builds molecular systems for LAMMPS. LUNAR automatically assigns atom types, generates bonded interactions, assigns charges, and provides initial configuration methods to generate large molecular systems. LUNAR can also incorporate chemical reactivity into simulations by facilitating the use of the REACTER protocol. Additionally, LUNAR provides postprocessing for free volume calculations, cure characterization calculations, and property predictions from LAMMPS thermodynamic outputs. LUNAR has been validated via building and simulation of pure epoxy and cyanate ester polymer systems with a comparison of the corresponding predicted structures and properties to benchmark values, including experimental results from the literature. LUNAR provides the tools for the computationally driven development of next-generation composite materials in the Integrated Computational Materials Engineering (ICME) and Materials Genome Initiative (MGI) frameworks. LUNAR is written in Python with the usage of NumPy and can be used via a graphical user interface, a command line interface, or an integrated design environment. LUNAR is freely available via GitHub.