Development Of Simulation Model Research Articles

Investigation on the Collection Mechanism of van der Waals Force in Air Filtration by Numerical Simulation and Empirical Model Development

Investigation on the Collection Mechanism of van der Waals Force in Air Filtration by Numerical Simulation and Empirical Model Development

Framework for Assessing the Sustainability Impacts of Truck Routing Strategies

The impact of freight on the transportation system is accentuated by the fact that trucks consume a greater roadway capacity than other vehicles and therefore cause more significant problems including traffic congestion, traffic delays, crashes, and pavement damage. Evaluating the actual repercussions of truck traffic becomes paramount in locales where roadway expansion is unfeasible. Trucks are vital to the economy, providing essential services to commerce and industry, and yet it is crucial that their operation does not contribute to the deterioration of infrastructural quality or compromise public safety. Currently, we lack methodologies in practice for the real-time management of traffic, specifically for truck routing, to minimize travel times and prevent delays due to non-recurrent congestion, such as traffic incidents. Accordingly, this study aimed to devise a truck routing strategy utilizing a traffic micro-simulation model (VISSIM) and to assess its effects on reducing travel delays. This involved the development of real-time truck re-routing simulation models that take into account non-recurrent congestion and the resulting travel delays and fuel consumption. The VISSIM model was applied to the I-75 corridor in Marion County, Florida, focusing on non-recurrent congestion effects on travel delays and fuel consumption. The initial findings suggest that the implementation of a dynamic truck re-routing system can significantly alleviate traffic congestion, resulting in a marked decrease in travel delays and fuel usage, demonstrating the potential for such strategies to enhance the overall efficiency of the transportation system.

Are digital servitization-based Circular Economy business models sustainable? A systemic what-if simulation model

Manufacturing companies are struggling with the implementation of Circular Economy, especially due to the uncertainty regarding its potential sustainability benefits. In particular, and despite digital servitization is advocated by several studies as a way to achieve environmental gains, circular business models based on digital servitization are not always sustainable due to burden shifting and unexpected consequences which are difficult to assess before implementation. This is particularly relevant for the Electrical and Electronics Equipment industry, which suffers structural weaknesses such as the dependance on critical raw materials and an increasing waste generation. However, literature lacks models and tools able to address the complexity inherent in the systemic micro-macro perspective envisioned by Circular Economy, while studies that quantitatively assess the sustainability impacts and trade-offs of digital servitization-based circular scenarios are limited. This article aims to develop a better understanding of how the sustainability impacts of circular and servitized scenarios can be assessed and quantified at the economic, environmental, and social level, adopting a systemic perspective through the development of a what-if simulation model. The model is implemented in a spreadsheet tool and applied to a digital servitization-based Circular Economy scenario inspired by the case of a company offering long-lasting, high-efficient washing machines as-a-service. Results show that digital servitization can actually lead to a win-win-win situation with net positive effects to the environment, the society, and the economy. This result is based on the joint application of product design for digitalization and life extension, pay-per-use business models, and product reuse. These results are robust within a significant range of key parameters values. Practitioners and policymakers may use the model to support the evaluation of different circular and servitized scenarios before implementation.

СПРОЩЕНА ІМІТАЦІЙНА МОДЕЛЬ НАВАНТАЖЕННЯ В ЗАМКНЕНІЙ МЕРЕЖІ КОМУТАЦІЇ ПАКЕТІВ

An approach to simplified simulation modeling of packet switching network load has been developed. The simulated representation of network processes is based on a simplified mathematical model of the packet switching network, which is based on a dis-cretized description of the load states of the network nodes and corresponds to the repre-sentation of the current state of the network in the tasks of managing its load. Changes in the node's filling state are modeled as a process of reproduction and death, and in the full load model, two factors of change are taken into account: the node's exchange of load with network users and transit load flow passing through it. To study an artificially se-lected "part of the network functioning process" - an approach to transit load modeling in a load-locked network is proposed. The approach allows for significant simplifications and ensures the leveling of the negative impact of simplifications on "load closure" (en-sures the rule of constant amount of load in a closed network). The developed simulation model, firstly, creates the basis for the improvement of the complete model, and secondly, it is convenient for working out routing algorithms when analyzing them from the point of view of indicators of the ability to "influence" the load in the network. The obtained re-sults are generalized, but attention is focused on the example of satellite packet switching networks.

Advanced hybrid numerical-machine learning computational study on fluid flow modeling in magnetic nanocarriers for targeted drug delivery

Development of comprehensive models for simulation of blood flow containing magnetic nanoparticles is of fundamental importance due to its application in medical science and cancer treatment. Owing to the complexity of the process, advanced hybrid models are preferred over conventional models. The focus of this study is on the application of machine learning models for predicting velocity in a given dataset to study the fluid flow in vessel containing magnetic nanocarrier for targeted cancer therapy. The numerical model was performed to simulate the blood flow through vessel, while the output data was used in developing machine learning models. The dataset is utilized to train three distinct models: Random Forest, Extra Tree, and AdaBoost Decision Tree. The hyper-parameter optimization is carried out via the Whale Optimization Algorithm (WOA) to improve the models' predictive capabilities. The dataset encompasses more than 17 thousand rows of data. The findings demonstrate the effectiveness of the suggested methodology, as evidenced by the impressive performance metrics exhibited by each model. The Random Forest model achieved a high R-squared value of 0.98768, indicating a robust fit to the data. The Root Mean Squared Error (RMSE) and Mean Absolute Percentage Error (MAPE) for Random Forest were recorded at 6.1223E-04 and 6.09246, respectively. Similarly, the Extra Tree model exhibited superior predictive accuracy with a score of 0.99151 with R-squared metric, showcasing its skill in uncovering the fundamental patterns present in the dataset. The associated RMSE and MAPE for Extra Tree were notably low at 5.1682E-04 and 1.20955E-01, respectively. The AdaBoost Decision Tree model exhibited notable efficacy, as evidenced by its R-squared score of 0.96944, albeit marginally lower than the other models. The RMSE and MAPE for AdaBoost DT were reported at 9.1863E-04 and 8.06333, respectively.

The MIDAS touch: Frameworks for procedural model innovation and validation

AbstractBackgroundSimulation‐based procedural practice is crucial to emergency medicine skills training and maintenance. However, many commercial procedural models are either nonexistent or lacking in key elements. Simulationists often create their own novel models with minimal framework for designing, building, and validation. We propose two interlinked frameworks with the goal to systematically build and validate models for the desired educational outcomes.MethodsSimulation Academy Research Committee and members with novel model development expertise assembled as the MIDAS (Model Innovation, Development and Assessment for Simulation) working group. This working group focused on improving novel model creation and validation beginning with a preconference workshop at 2023 Society for Academic Emergency Medicine Annual Meeting. The MIDAS group sought to (1) assess the current state of novel model validation and (2) develop frameworks for the broader simulation community to create, improve, and validate procedural models.FindingsWorkshop participants completed 17 surveys for a response rate of 100%. Many simulationists have created models but few have validated them. The most common barriers to validation were lack of standardized guidelines and familiarity with the validation process.We have combined principles from education and engineering fields into two interlinked frameworks. The first is centered on steps involved with model creation and refinement. The second is a framework for novel model validation processes.ImplicationsThese frameworks emphasize development of models through a deliberate, form‐follows‐function methodology, aimed at ensuring training quality through novel models. Following a blueprint of how to create, test, and improve models can save innovators time and energy, which in turn can yield greater and more plentiful innovation at lower time and financial cost. This guideline allows for more standardized approaches to model creation, thus improving future scholarship on novel models.

Financial system dynamics model for multidimensional flexibility in toll road PPPs: a life-cycle analysis

Although scholars have developed simulation models and analyzed bankability criteria in numerous papers to enhance the financial outcomes of Public-Private Partnerships (PPPs), the intersection between both fields considering alternatives to assess the financial impact of flexibility in both scope and financing, remains underdeveloped. To address this gap, this paper introduces a financial model that assesses the financial impact of suitable life-cycle flexibility alternatives while coexisting with revenue performance alterations in each project phase within toll road PPPs. This model serves as a tool to gain insight into the planning of strategic actions to implement flexibility in both scope and financing. Based on system dynamics and validated using financial data from two toll road PPPs in India and East Europe, simulation results suggest that two key drivers (capital expenditures and debt repayment period) have the greatest influence on financial performance. Findings support the implementation of flexible scopes to effectively address the most influential exogenous factor impacting the financial performance of PPPs, namely traffic shortfalls. This model provides a suitable tool for assessing the life-cycle economic sustainability of PPPs in uncertain and complex environments.

Investigating Tailless UAV Flight Dynamics through Modeling, Simulation, and Flight Testing

Tailless Unmanned Aerial Vehicles (UAVs) offer several advantages over their conventional counterparts, including enhanced maneuverability, higher durability, and better stealth. However, they are challenging in their stability and control due to the absence of stabilizing and control surfaces that typically exist in conventional empennage. A crucial process for analyzing the tailless UAVs’ stability/performance characteristics and determining/validating their flight control parameters is done via the modeling and simulation of flight dynamics. This paper presents a comprehensive and systematic procedure for investigating the flight dynamics of a tailless UAV, including modeling, simulation, analytical verification, and flight testing, while also explaining the interconnections among these elements. It also addresses the common challenge of limited accessibility of UAV essential data through using diverse analytical, empirical, and experimental methods. First, a rapid and effective first-principles modeling approach is introduced to simulate the nonlinear six-degree-of-freedom flight dynamics of a small tailless UAV case study. The modeling process follows a modular framework where well-defined experiments and commercial of-the-shelf software, tools, and sensors are employed to build the necessary sub-models, including geometric, mass–inertia, aerodynamic, propulsion, and actuator models. Then, all sub-models are integrated into a simulation environment to allow the prediction of the UAV dynamic response obtained from the given control inputs. The developed flight dynamic model is subjected to a thorough verification process to ensure its integrity and proper functionality by comparing the simulated trim and natural flight modes with the calculated analytical results. Finally, a set of specific flight tests are performed to validate the developed simulation model and verify relevant performance characteristics for the case-study UAV. The results show that the proposed approach provides a systematic and straightforward method for examining the flight dynamics of small tailless UAVs with reasonable accuracy.

SIMPLIFIED SIMULATION MODEL OF LOAD IN A CLOSED PACKET SWITCHING NETWORK

An approach to simplified simulation modeling of packet switching network load has been developed. The simulated representation of network processes is based on a simplified mathematical model of the packet switching network, which is based on a discretized description of the load states of the network nodes and corresponds to the representation of the current state of the network in the tasks of managing its load. Changes in the node's filling state are modeled as a process of reproduction and death, and in the full load model, two factors of change are taken into account: the node's exchange of load with network users and transit load flow passing through it. To study an artificially selected "part of the network functioning process" - an approach to transit load modeling in a load-locked network is proposed. The approach allows for significant simplifications and ensures the leveling of the negative impact of simplifications on "load closure" (ensures the rule of constant amount of load in a closed network). The developed simulation model, firstly, creates the basis for the improvement of the complete model, and secondly, it is convenient for working out routing algorithms when analyzing them from the point of view of indicators of the ability to "influence" the load in the network. The obtained results are generalized, but attention is focused on the example of satellite packet switching networks.

Physical Modeling and Simulation of Reusable Rockets for GNC Verification and Validation

Reusable rockets must rely on well-designed Guidance, Navigation and Control (GNC) algorithms. Because they are tested and verified in closed-loop, high-fidelity simulators, emphasizing the strategy to achieve such advanced models is of paramount importance. A wide spectrum of complex dynamic behaviors and their cross-couplings must be captured to achieve sufficiently representative simulations, hence a better assessment of the GNC performance and robustness. This paper focuses on of the main aspects related to the physical (acausal) modeling of reusable rockets, and the integration of these models into a suitable simulation framework oriented towards GNC Validation and Verification (V&V). Firstly, the modeling challenges and the need for physical multibody models are explained. Then, the Vertical Landing Vehicles Library (VLVLib), a Modelica-based library for the physical modeling and simulation of reusable rocket dynamics, is introduced. The VLVLib is built on specific principles that enable quick adaptations to vehicle changes and the introduction of new features during the design process, thereby enhancing project efficiency and reducing costs. Throughout the paper, we explain how these features allow for the rapid development of complex vehicle simulation models by adjusting the selected dynamic effects or changing their fidelity levels. Since the GNC algorithms are normally tested in Simulink®, we show how simulation models with a desired fidelity level can be developed, embedded and simulated within the Simulink® environment. Secondly, this work details the modeling aspects of four relevant vehicle dynamics: propellant sloshing, Thrust Vector Control (TVC), landing legs deployment and touchdown. The CALLISTO reusable rocket is taken as study case: representative simulation results are shown and analyzed to highlight the impact of the higher-fidelity models in comparison with a rigid-body model assumption.

ІДЕНТИФІКАЦІЯ ПОЇЗДІВ ІЗ СПІЛЬНИМ ВИКОРИСТАННЯМ ІНФОРМАЦІЇ З РІЗНИХ ДЖЕРЕЛ

Creating of information and control systems, rolling unit traffic control systems, both within the station and on the adjacent tracks, is closely linked to the identification systems. This paper describes the procedure of the identification method allowing to determine а train from the list of possible. This uses a data of the control section and a data of the top-level information systems. To achieve the set purpose the simulation method and experiment planning method were used. The developed simulation model of the identification method allows you to check the correct operation of different algorithms for identifying rolling units. The results of this work can be used to identify both individual rolling units and the whole train.

Non-uniform temperature fields in steel tubes with different inclinations under solar radiation

The temperature distribution within steel tubes is subject to non-uniformity due to the influence of surrounding environmental factors, which could pose safety concerns for steel structures. In response, this study undertook a comprehensive long-term experimental investigation, aimed at elucidating the temperature distribution characteristics of inclined steel tubes. The results underscored the non-uniform distribution of temperature fields in steel tubes under the influence of solar radiation, with notable sensitivity to their inclinations and orientations. In addition, a numerical simulation model specifically tailored to represent the thermal behavior of inclined steel tubes was developed and subsequently validated using empirical data gathered from the aforementioned experiments. Based on the developed simulation model, the thermal behaviors of a steel-arch-tower were numerically analyzed. It was shown that distinct vertical temperature variations exist across different sections of the tower, while the horizontal temperature differentials exhibit consistent trend. The outcomes of this combined experimental and numerical study provide useful references to understand the thermal effects in steel structures.

Agent-based modeling and optimization of the characteristics for research-and-production clusters

This paper presents a developed agent-based simulation model for the development of research-and-production clusters in Russia implemented with the use of high-tech enterprises located in four science cities (Troitsk, Obninsk, Pushchino and Protvino) as the case study. A new approach to modeling and optimization of gross metropolitan product (GMP) is proposed, taking into account the influence of the “gravity effect” on the redistribution of labor resources between developing science cities and appropriate enterprises united in single research and research-and-production clusters An important element of this approach is the formation of various scenarios for the strategic development of the research-and-production clusters being assessed and support for the possibility of choosing the most preferable scenario using an evolutionary optimization algorithm. An enlarged simulation model has been developed and implemented in AnyLogic describing the possible development trajectories of science cities with a corresponding change in the values of the most important characteristics: the number of economically active population, the number of research-and-production enterprises, the volume of products produced in high-tech sectors of the economy, GMP, etc. The designed framework is intended primarily for the management of research-and-production clusters implementing the strategy of innovative development. Such a framework uses methods of system dynamics and agent-based simulation modeling supported in the AnyLogic system, genetic optimization algorithms and GIS mapping for science cities, etc. to implement the required functionality. The approbation of the framework was completed with the use of real data published in the approved strategies of the relevant science cities development. As a result of the numerical experiments carried out, some recommendations were proposed for the development of the research-and-production clusters under study considering their mutual influence and the existing base of resources.

Advanced multi-scale analysis of segregation mechanisms in twin-roll casting of Al-Cu-Li alloys

In this paper, a detailed analysis of the rheological behaviour and segregation mechanisms within twin-roll casting (TRC) processes for 2060 Al-Cu-Li alloys is presented. Building on previous research where fixed roll gaps limited the adjustability of cast-rolling speed, this study expands the scope by adjusting roll gaps from 3 mm (TRC-3), to 6 mm (TRC-6), to 10 mm (TRC-10). This approach yields three typical process ranges with gradually increasing roll gaps and a wide range of decreasing cast-rolling speeds, allowing us to investigate the inherent nature of segregation and identify conditions conducive to segregation-free processing. A significant contribution of this study is the development of a novel multi-scale simulation model that integrates the thermal, flow, mechanical, solute and phase fields. This advanced simulation framework enhances our understanding of TRC processes and aids in exploring the interplay between the various factors affecting alloy fabrication. This study identified two primary stress-induced inverse segregation mechanisms: the reflux of the semi-solid phase due to rolling stress and expansion of the solidifying shell under shearing stress. Using these insights, a low-stress, low-segregation process, termed TRC-6, was established, which showed notable improvements in the mechanical properties. Specifically, TRC-6 demonstrated a remarkable strength of 562.9 MPa post-T8-treatment, surpassing those of TRC-3 and TRC-10 by 9.0 % and 5.2 %, respectively. These findings offer valuable insights for future TRC process designs with the aim of eliminating segregation defects and enhancing the sustainable and efficient production of Al-Cu-Li alloys.

Development of electricity simulation model of urban houses and evaluating surplus electricity of photovoltaics (PV) considering housing stock transformation

The Japanese government is advocating for the introduction of decentralized renewable energy devices such as photovoltaics (PV) and high thermal performance houses in urban areas. Due to variations in housing stock among different urban areas, the implementation of these houses and devices would have diverse effects on the supply and demand sides, potentially leading to diverse overproduction of PV electricity, referred to as surplus electricity. Existing research focuses on increasing the utilization of surplus electricity and quantifying the surplus electricity from individual buildings at a regional scale. Considering the lack of research that quantifies surplus electricity through shared PVs under the urban-scale contextual changes (widespread introduction of high-performance houses). Therefore, this study aims to address this gap by utilizing an archetype house simulation model to simulate and compare two scenarios (with or without houses retrofitting) regarding electricity demand for each street-level area, maximum power and duration time of surplus electricity in areas where surplus electricity would occur in the target city Fukuoka in 2025. The results indicate that, under the current residential PV stock and existing introduction rates, the peak surplus power occurs around noon in May, approximately 396 out of 1051 areas in Fukuoka would generate surplus electricity during 2025. Houses retrofitting would increase the surplus electricity (include maximum power and duration time) in these areas. Additionally, this study identifies the residential characteristics of areas that generate surplus electricity, including construction year, household composition, and the proportion of detached houses, whether with retrofitting or not. The results suggest attention to surplus electricity increasing in areas with a high proportion of detached houses when considering houses retrofitting.

Analysis of two-terminal perovskite/silicon tandem solar cells with differing texture structure, perovskite carrier lifetime, and tunneling junction quality

Presented here is the optimization of a planar two-terminal perovskite/silicon tandem solar cell with a texture structure. The developed simulation model is fitted to published experimental results, and the importance of current matching in the two-terminal structure is discussed. With the texture structure optimized and considering current matching, the optimal texture structure improves Jsc from 17.9 to 20.87 mA/cm2 compared to the planar structure, as well as improving the power conversion efficiency from 25.8% to 35.9%. Furthermore, if the quality of the perovskite thin film and tunneling junction efficiency with a smaller voltage penalty can be improved, then the efficiency can be further improved to 38.13%. This indicates that this tandem solar cell still has much room for improvement.

Study of a Thermochemical Heat Storage Reactor Filled with Polyaluminum Sulfate for Low-Temperature Application

This paper investigates comprehensively the operational dynamics of a thermochemical heat storage (TCHS) reactor for low-temperature applications using polyaluminum sulfate and takes into consideration a developed simulation model with an experimentation validation. Significant concordances were found between the developed simulation model and the experimental results. Results reveal optimized conditions for the charging process using an electrical heater, with a heating temperature of 120°C at 10 K/min over 500 minutes. This achieves full material charging, with stabilized pressure drops at an equilibrium of 80 mbar, corresponding to a temperature of approximately 108°C, and yielding a thermal power of 950 W. An inlet vapor pressure of 18 mbar at 10°C for 5 hours is sufficient to completely discharge the bed, with pressure drops reaching around 30 mbar and a thermal power of 300 after reaction completion. Insights into conversion extents during both processes are provided, along with a remarkable thermal efficiency of 90% and a coefficient of performance (COP) of 97%, surpassing recommended theoretical values (50%). The study suggests further enhancing system performance through the design and implementation of a dedicated heat exchanger. The achievement of 75% of the targeted thermal power specification represents a significant milestone, offering valuable contributions towards the realization of sustainable technological advancements of both the reactor technology of TCHS and state-of-the-art thermal energy storage solutions. From the research, it is possible to infer further suggestions for enhancing this performance by designing and implementing a dedicated heat exchanger for both heat supply and retrieval mechanisms.

High-fidelity 3D simulation of dust-loading behavior and clogging process of coarse nonwoven filter media considering collision effect

The filter lifetime of fibrous media is important for the energy-saving application of air filters and efficient delivery of clean air. The clogging process significantly affects the dust-loading behavior of fibrous filter media. Therefore, an effective methodology for determining the deposition of dust particles inside filter structures is necessary. This study conducted numerical dust loading simulations on a three-dimensional (3D) X-ray tomographic structure of coarse nonwoven filter media. Spherical particles with a density of 1808 kg/m3 were used in the simulations instead of plate-like dust particles with a higher silica density. A high-fidelity simulation model was successfully developed by considering collision effects. Key factors were determined, including the Hamaker constant for the adhesion energy, restitution coefficient for the particle kinetic energy, and sliding motion. Remarkably, the deviation between the simulated and experimental dust holding capacity was less than 1 %. The developed simulation model enabled a quantitative evaluation of the clogging process and 3D in-situ evolution of particle deposition and pore structures. It was observed that 95.6 % of the maximum deposited dust mass within the fibrous structure was captured at the clogging point. Several computational methods yielded accurate pore size evaluations and clear 3D pore structure visualizations. The developed methodology for high-fidelity simulation and 3D analysis can be further applied to other two-phase filtration and separation fields, including aerosol filtration, coalescence filtration, membrane fouling, micro/nanoplastic capture, and oil/water separation.

Experimental process characterisation for high-volume compression moulding of hybrid-architecture composites

Compression moulding of woven fabric prepreg and sheet moulding compound (SMC) in a single-shot process combines the superior mechanical properties of continuous fibre composites and the high design flexibility of discontinuous fibre composites. This experimental study presents insights into the moulding characteristics of prepreg and SMC and explores the interaction between these two materials during manufacturing of hybrid-architecture composites. All tests were performed under typical compression moulding conditions using a squeeze flow testing rig. The response of each material was interpreted through proposed material models applied to the data acquired from single architecture tests. Critical interaction mechanisms were identified from hybrid architecture tests, alongside some additional deformation mechanisms, such as high level of in-plane fibre tow deformation not observed in single-architecture tests. Novel experimental methods were also introduced to quantify the change in meso-scale fibre architecture in the prepreg induced by the flow of SMC. The outcomes of this study not only shed light on the essential interaction mechanisms of hybrid-architecture composites but also provide valuable insights into deformation mechanisms not apparent in isolated material studies. Ultimately, these findings will facilitate the future development of a numerical simulation model for hybrid moulding processes.

Implementation of Simulation Modeling of Single and High-Volume Machine-Building Productions

The authors of this article analyze the existing methods and models of technological preparation of machine-building industries. The structure of a three-level simulation model with network-centric control, the structures of individual elements of the simulation model, and the process of simulation modeling are described. The criteria for choosing a rational option for the processing technological route have been determined. During this research, a simulation program was implemented in C++. It allows you to select the optimal scenario for the operation of a production site based on two criteria: time and cost. The volume of implementation is about 2 × 103 lines of code. A diagram of the modeling algorithm for the implemented program and a description of the classes and their interactions are given in the article. The developed simulation model was tested at a machine-building enterprise using the example of the “Pusher” part, manufactured under single-unit production conditions. The technological equipment used for the manufacture of this part was formed in the form of input data of the simulation model. The results of simulation modeling for the selected part are described. For each variant of the technological processing route, the values of variable costs and the duration of the production cycle were determined.