Development Of Simulation Model Research Articles

WheatSM V5.0: A Python-Based Wheat Growth and Development Simulation Model with Cloud Services Integration to Enhance Agricultural Applications

This project aims to improve the wheat growth and development simulation model (WheatSM) V4.0, a renowned wheat model, by addressing limitations in its structure and modules. The WheatSM V4.0 excelled numerically but lacked modularity, hindering maintenance, improvement, and secondary development. Therefore, the project undertook a software framework redesign, adopting a modular approach and implementing WheatSM V5.0 entirely in Python. Furthermore, the project conducted a sensitivity analysis of model parameters. Additionally, WheatSM V5.0 was seamlessly integrated into AgroStudio, an agricultural model system integration platform, enabling the provision of online cloud services. The Morris analysis indicated that photoperiod parameters significantly impacted the jointing and mature stages. Furthermore, biomass was highly sensitive to pmax (the maximum photosynthetic intensity at light saturation point), while yield was influenced by tr1 (the transfer rate of photosynthate to grain before heading). The simulated results demonstrated favorable performance in soil water storage, soil nitrate nitrogen content, winter wheat nitrogen accumulation, the development period, biomass, and yield. The NRMSE ranged from 1.2% to 15.1% for calibration and 1.0% to 18.7% for validation. The project successfully transformed WheatSM into a cloud-based service on AgroStudio, migrating from a PC-based application. Generally, this enhanced model exhibits potential for climate change assessment, wheat production optimization, and digital design.

A Review of Biomass Thermal Analysis, Kinetics and Product Distribution for Combustion Modeling: From the Micro to Macro Perspective

Driven by its accessibility, extensive availability, and growing environmental consciousness, solid biomass has emerged as a viable alternative to enhance the diversity of renewable energy sources for electricity generation. To understand the phenomena involved in solid biomass conversion, it is necessary not only to understand the stages of the biomass combustion process but also to understand specifically the kinetics of the reaction and the release of the volatiles. The present work presents an overview of the existing literature on several topics related to the biomass combustion process, its characterization, as well as strategies to develop simple and effective models to describe biomass conversion with a view to the future development of numerical simulation models. Since the focus of most of the investigations is the development of a numerical model, a summary and identification of the different model assumptions and problems involved in thermal analysis experiments are presented. This literature review establishes the significance and credibility of the research, providing the main concepts and assumptions with a critique on their validity. Hence, this work provides specific contributions from a multi-scale perspective which can further be extended to provide insights into the design and optimization of biomass combustion technologies, such as boilers and furnaces.

Experimental and numerical study of coupling effects between vessel motion and pipeline tension in deepwater J-laying

During deepwater J-lay operations, the J-lay vessel and pipeline together form a coupled system. The dynamic responses of this system, including the vessel motion and pipeline tension caused by environmental loads, inevitably exhibit coupling effects. This paper describes the results of experimental and numerical studies conducted to investigate the effects of vessel–pipeline coupling on the global dynamic responses of J-lay vessels and pipelines under irregular wave conditions based on practical engineering. Large-scale full-depth experiments of the complete system are conducted in a 10-m-deep wave basin. The similarity of both the submerged unit weight and pipeline stiffness is considered in the design of the pipeline model. Numerical simulations are performed to further investigate the coupling effects on the dynamic characteristics of vessel motion and pipeline tension, and to analyze the coupling effects of J-lay operations in greater water depths. The results reveal that the coupling effects between the J-lay vessel and the pipeline are nonnegligible for both the vessel motion and pipeline tension responses in J-lay operations. The influence of these coupling effects is strongly related to the operation depth and pipeline properties. Overall, this study provides a reference for the design of J-lay systems and the development of J-lay simulation models.

Numerical Modeling, Experimental Investigation, and Optimization of a Micro Hot Embossing Process

Abstract This paper describes the development of a finite element simulation model and a self-made low-cost experimental setup for the micro hot embossing process. The simulation model incorporates stress relaxation behavior through the utilization of the generalized Maxwell model. It also considers thermal expansion and contact friction effects, enabling accurate prediction of the deformed pattern of polymethyl methacrylate (PMMA). Simulations and experiments were performed for various pressure and temperature combinations, and the resulting pattern profile depths were found to be in good agreement, between the simulation and experimental results. In addition, the simulation model was used to generate response surfaces through face-centered central composite design (CCD) to identify the ideal combination of process parameters of the micro hot embossing process for creating a patterned SMD (surface mount device) LED chip panel.

Optical ray-tracing simulation method for the investigation of radiance non-uniformity of an integrating sphere

The paper deals with possibilities and limits of optical simulations of extended uniform light sources. Optical simulations of ideal and real light sources are performed using optical ray-tracing software which is capable to simulate non-imaging systems such as Lambertian disc and integrating spheres. The simulation methodology is validated by comparing the developed simulation model with a real experiment previously performed in optical laboratory. The comparison is made on the radiance uniformity measurement and simulation results of a general purpose integrating sphere rather than on less convenient and more frequent irradiance uniformity measurements. The aim is to develop a reliable simulation method for the investigation of radiance non-uniformity of any real extended uniform light source.

Improving performance of air conditioning system by using variable-circuit heat exchanger: Based on the Chinese APF standard

For finned-tube heat exchangers, owing to the extremely different refrigerant pressure drop characteristics between condensation and evaporation processes, the optimum refrigerant circuits of these two conditions are different. However, for a typical heat pump type air conditioner, refrigerant circuit of the conventional heat exchanger (CHX) is fixed no matter what operation condition is conducted. To solve this problem, a modified variable-circuit heat exchanger (VCHX) is developed for air conditioner outdoor unit applications. The VCHX, for which the refrigerant circuit can be easily switched by using a globe valve, could provide better matching characteristics between refrigerant circuit and operation condition variations. With a developed simulation model, refrigerant circuit of the VCHX is optimized by using the entropy generation minimization theory. Then, comparative experimental works were conducted to investigate the performance of VCHX and CHX systems in detail. Experimental results show that the presented VCHX is more suitable for high heating capacity and low cooling capacity applications. Based on the Chinese APF (annual performance factor) Standard, the VCHX system yields 6.5% higher APF value over CHX system. Significantly, economic analysis indicates that the investment payback period of VCHX system is 1.46 year, which is much lower than the designed lifetime of a residential air conditioner. In general, the VCHX technique has a great application potential for improving the overall performance of a heat pump type air conditioner.

1267 Application of the Low-Cost Laparoscopic Appendicectomy Simulation (LaApSi) Model for Laparoscopic Training in Low-Middle-Income-Countries (LMIC) and Its Comparison with the Laparoscopic Skills Session in the UK

Abstract Aim To assess the LaApSi Model’s effectiveness in the surgical simulation within and outside the UK. To assess the delegates' expectations while simulating Laparoscopic Appendicectomy (LA) using LaApSi Model. Method LaApSi models were developed using 3D printed mould & Silicon with a production cost under £5 pp. Within 6 months of model development, the quantitative assessment of LaApSi model was done by 18 trainees from LMICs (RCSEd endorsed Laparoscopic Course) and 29 within the UK, 2 Laparoscopic courses (LC) and 1 Intermediate Surgical Skills Course (ISS) evidenced by formal feedback which has further led to the production of the modified version. Results For LMICs Lap-courses, 88.9%, n = 16 delegates agreed that the LaApSi model was able to meet their learning objectives whereas it was around 80% for UK courses. Similarly, 90%, n = 16 delegates agreed they were able to understand the General Steps Involved in LA, were more confident with LA and felt the course was relevant whereas it was around 15% less in these domains during UK Lap courses. 80.3% n = 5 delegates responded that the LaApSi model was equally effective in simulating Open Appendicectomy (OA) in a recent ISS course. Conclusions There is an unmet need for the development of a Low-Cost simulation model in LMICs and these cost-effective LaApSi models can provide a safe and standardized method for simulation training before operating on real patients. Although the model expectations were found relatively higher among UK delegates, feedback establishes a positive impact of the model among the course delegates.

Simulation of local metastable microstructural states in large tools: construction and validation of the model

This study presents the development and experimental verification of a simulation model for estimating the local microstructure of a tool geometry after heat treatment. The experiment involved subjecting a metallic block of dimensions 40 × 50 × 50 mm, made of the ledeburitic cold work steel DIN EN 1.2379 (X153CrMoV12; AISI D2), to a heat treatment in a laboratory furnace at 1000 °C for 20 min. Thermocouples were strategically placed to record time-temperature profiles at different locations within the block. Following the heat treatment, the local microstructure was determined through quantitative image analysis, and the local hardness was measured as a function of the distance from the block’s edge to its core. These measurements were then correlated with the corresponding time-temperature curves obtained from the thermocouples. To replicate the local time-temperature profiles, the thermophysical properties of the steel were experimentally determined and incorporated into a finite element analysis heat transfer simulation using Abaqus FEA® software. This simulation approach, combined with the MatCalc software, facilitated the calculation of various local microstructural characteristics such as carbide content, carbide type, carbide distribution, and chemical composition of the matrix. Furthermore, the content fractions of the microconstituents of the matrix, including martensite and retained austenite, were determined based on the simulated martensite start temperature, employing an optimized function fitted to experimental data. The developed simulation model offers potential applications in two important areas. Firstly, it can be used to adapt heat treatment processes for tools of different sizes in production, optimizing their mechanical properties. Secondly, it enables efficient optimization of heat treatment routes by considering changing initial states, leading to high process quality in terms of mechanical properties. Overall, this study provides valuable insights into the estimation and control of local microstructure in tool geometries through the use of a validated simulation model.

A simulation evacuation framework for effective disaster preparedness strategies and response decision making

The damage and destruction of homes, buildings, and other infrastructure after a major earthquake makes it necessary for a segment of the population to be evacuated to emergency shelters. However, since areas prone to earthquakes face a major strike at highly unpredictable and infrequent times, disaster and evacuation management can and should be enhanced through the development and effective utilization of useful simulation models. We utilize the Stochastic Pedestrian Cell Transmission Model (SPCTM), a real data-based pedestrian evacuation simulation framework built in collaboration with the National Science and Technology Center for Disaster Reduction (NCDR) in Taiwan to carry out various statistical analyses to gain useful insights for disaster management decision makers. In particular, SPCTM is used to (1) examine how evacuee compliance rate with the current government evacuation protocol (as opposed to SPCTM) affects the total evacuation time (2) compare the results of the evacuation process for different neighborhoods and compliance rates in Da’an district, and (3) determine how allocating different subsets of shelters to be opened affects the evacuation response time. The analysis results are insightful for government officials to formulate effective evacuation guidelines and strategies in the preparedness or response phases.

Computer Simulation Modeling of an Inhomogeneous Medium with Ellipse-Shaped Irregular Elements

The article substantiates the main possibilities of filling with irregular bodies, and provides a visual analysis of the parameters formed as a result of structures. It was found out that the form factor acts as the main indicator of the characteristic parameter of changes in the structure and all other parameters of an inhomogeneous medium. It was also found out that when filling a container with irregular ellipsoid elements, the conditions for non-opening (one-way contact) must be met. The obtained calculations of the form factor show the minimum value of the average coordination number of an inhomogeneous medium. This allows us to assert and predict reliable modelling results (± 2-3%). It is also important that the developed simulation model for modelling an inhomogeneous medium using an irregular (ellipsoid) shape of elements can significantly reduce the time spent on conducting field experiments, as well as simulate irregular elements with different shape factors.

Development of a Comprehensive Water Simulation Model for Water, Food, and Energy Nexus Analysis in Basin Scale

Development of a Comprehensive Water Simulation Model for Water, Food, and Energy Nexus Analysis in Basin Scale

Simulation-Based Headway Optimization for the Bangkok Airport Railway System under Uncertainty

The ever-increasing demand for intercity travel, as well as competition among all modes of transportation, is an unavoidable reality that today’s urban rail transit system must deal with. To meet this problem, urban railway companies must try to make better use of their existing plans and resources. Analytical approaches or simulation modeling can be used to develop or change a rail schedule to reflect the appropriate passenger demand. However, in the case of complex railway networks with several interlocking zones, analytical methods frequently have drawbacks. The goal of this article is to create a new simulation-based optimization model for the Bangkok railway system that takes into account the real assumptions and requirements in the railway system, such as uncertainty. The common particle swarm optimization (PSO) technique is combined with the developed simulation model to optimize the headways for each period in each day. Two different objective functions are incorporated into the models to consider both customer satisfaction by reducing the average waiting time and railway management satisfaction by reducing needed energy usage (e.g., reducing operating trains). The results obtained using a real dataset from the Bangkok railway system demonstrate that the simulation-based optimization approach for robust train service timetable scheduling, which incorporates both passenger waiting times and the number of operating trains as equally important objectives, successfully achieved an average waiting time of 11.02 min (with a standard deviation of 1.65 min) across all time intervals.

A new heat resistant load bearing system incorporating honeycomb structured cementitious composite investigated via experiments and modelling

The load-bearing cementitious materials such as concrete rely on passive insulation to resist heat in fire and other high-temperature events. This study introduces a novel load-bearing system, incorporating a honeycomb-structured cementitious composite (HSCC) to enable adjustable active heat dissipation. Compared with passive thermal insulation, active heat dissipation brings substantial improvement on heat resistance performance under compressive load. The study investigated the heat transfer process of the HSCC material fabricated by 3D-printed micro scaffolds by combining the microscopic thermal imaging method and finite element simulation. The proposed material has a conductivity of up to 0.24 W/mK, which shows a 30% improvement in heat resistance compared to lightweight concretes. The total compressive strength reduction is ten times less than ordinary concrete under elevated temperatures at 1300 °C. The microscopic thermal imaging provided experimental data to enable the development of multi-phase simulation models, which allowed further predictions of the material performance under elevated temperatures. The novel load-bearing system enabled ventilation through the HSCC in combination with the low thermal conductivity of the HSCC, which allowed this novel system to demonstrate a capacity loss at 1300 °C that was ten times less than that of ordinary concrete walls. Furthermore, the effect of ventilation and heterogeneity in the HSCC on the heat dissipation and temperature distribution in the materials is also characterized by this study.

Required strength design of cemented backfill for underground metalliferous mine

ABSTRACT Determination of the minimum required strength of backfill is the key design aspect for underground mining with backfill. In this study, a 3D simulation model was developed for predicting the required strength of backfill and displacement contours, yield state, and strength/stress ratios were considered to evaluate the stability and failure mechanism of backfill. The backfill design strength, assessed from numerical modelling, was compared with the previously developed analytical solutions. Further, the developed 3D simulation model was successfully used for backfill strength estimation of a few underground stopes in Eastern and Western India.

Developing a supervised learning-based simulation method as a decision support tool for rebalancing problems in bike-sharing systems

Bike-Sharing Systems (BSSs) have exploded in popularity worldwide because of their beneficial impacts on traffic, pollution levels, and public health, which has resulted in moving toward a green city. The rebalancing problem, as one of the most important operational problems of such systems, deals with planning bike distribution at different stations. Regarding conducted studies, simulation models are the most common tool for analyzing BSSs and decision-making. This popularity is based on simulation’s capabilities in modeling complexities of systems and uncertainty. Despite their advantages, lack of quickness is a significant drawback of simulation-based methods, making them inefficient for real-time decision-making processes, especially in large-scale and complex systems. In this regard, this paper introduces a Supervised Learning-Based Simulation (SLBS) method as an alternative to the conventional simulation-based methods dealing with rebalancing problems. SLBS is a huge step toward developing a real-time Decision Support System (DSS) for BSSs. For developing SLBS, firstly, we have developed a simulation model based on real-world assumptions of station-based BSSs and big data analysis of CitiBike, a well-known BSS located in New York City. The simulation model is able to calculate the number of unsatisfied demands (either number of failed pick-ups (FPs) or failed drop-offs (FDs)) as a result of different rebalancing plans. Then, the developed simulation model was used to generate quality and quantity training datasets to train Machine Learning (ML) algorithms involved in SLBS. While these ML models are trained once, SLBS will be capable of predicting the number of unsatisfied demands without running highly time-intensive simulations replications. The results obtained from a wide range of conducted experiments indicate that SLBS, up to 300 times faster than simulation models, can provide predictions with over 90% of R2 Score.

Wheel Defect Detection Using a Hybrid Deep Learning Approach.

Defective wheels pose a significant challenge in railway transportation, impacting operational performance and safety. Excessive traction and braking forces give rise to deviations from the intended conical tread shape, resulting in amplified vibrations and noise. Moreover, these deviations contribute to the accelerated damage of track components. Detecting wheel defects at an early stage is crucial to ensure safe and comfortable operation, as well as to minimize maintenance costs. However, the presence of various vibrations, such as those induced by the track, traction motors, and other rolling stock subsystems, poses a significant challenge for onboard detection techniques. These vibrations create difficulties in accurately identifying wheel defects in real-time during operational activities, often resulting in false alarms. This research paper aims to address this issue by using a hybrid deep learning-based approach for the accurate detection of various types of wheel defects using accelerometer data. The proposed approach aims to enhance wheel defect detection accuracy while considering onboard techniques' cost-effectiveness and efficiency. A realistic simulation model of the railway wheelset is developed to generate a comprehensive dataset. To generate vibration data in various scenarios, the model is simulated for 20 s under different conditions, including one non-faulty scenario and six faulty scenarios. The simulations are conducted at different speeds and track conditions to capture a wide range of operating conditions. Within each simulation iteration, a total of 200,000 data points are generated, providing a comprehensive dataset for analysis and evaluation. The generated data are then utilized to train and evaluate a hybrid deep learning model, employing a multi-layer perceptron (MLP) as a feature extractor and multiple machine learning models (support vector machine, random forest, decision tree, and k-nearest neighbors) for performance comparison. The results demonstrate that the MLP-RF (multi-layer perceptron with random forest) model achieved an accuracy of 99%, while the MLP-DT (multi-layer perceptron with decision tree) model achieved an accuracy of 98%. These high accuracy values indicate the effectiveness of the models in accurately classifying and predicting the outcomes. The contributions of this research work include the development of a realistic simulation model, the evaluation of sensor layout effectiveness, and the application of deep learning techniques for improved wheel flat detections.

How to achieve energy efficiency and sustainability of large ships: a new tool to optimize the operation of on-board diesel generators

In this paper a novel dynamic simulation model for enhancing the sustainability of transportation systems equipped with diesel co-generators is presented. In each simulation time step of the carried out energy performance analyses, the best operation/combination of generators as well as their optimal part load ratio are determined with the aim to achieve the minimum fuel consumption. Input to the model are: size of each installed diesel generator; number of engines; required power profile; route scheduling and hourly weather data. The developed simulation model is implemented in TRNSYS environment. Here, a new in-house TRNSYS type written in Fortran is also included. With the presented approach - especially helpful for cruise ship designers, manufacturers and owners - new design criteria and useful technical results can be obtained.To show the capability of the tool a novel case study is presented. It concerns on an existing cruise ship to be refurbished from the energy point of view. Here, four diesel generators are installed on-board. The ship energy system includes five electric chillers, two auxiliary boilers, two reverse osmosis and two multi-stage flash desalination devices (driven by the diesel generators waste heat recoveries). Simulation results show remarkable energy savings obtained through the proposed optimization approach. Specifically, a maximum primary energy saving of about 15 GWh/y is obtained compared to the initial reference scenario. It corresponds to a fuel consumption reduction of 2.5 kt/y (-1.6 M$/y) and to an avoided CO2 emission of 8.0 kt/y.

Thermophysiological coupled analysis with COM, ES, and CFD

The introduction of simulation technologies has resulted in the growth of analytical results that can be implemented in building design. Energy simulations (ESs) and computational fluid dynamics (CFD) are primarily used in building energy simulations. Although the predicted mean vote (PMV) obtained from simulation results is typically used as a human-body evaluation index, the heat balance of a human thermal model is more precise. Moreover, the PMV should be calculated based on unsteady thermophysiology. Therefore, this study forms the initial phase for the thermophysiological estimation of unsteady analysis and “focused” case studies, such as steady-state analysis, in an environment where forced convection is dominant. It was revealed that the convective heat-transfer coefficient (CHTC) was dominant in a forced convection field; therefore, the convergent calculation in the suggested coupled analysis model was not necessary when comparing the results of human thermophysiology. The difference between the temperatures of the skin surface and that obtained with clothing using the convergent calculation was a maximum of 0.5 °C. We conducted comparative tests between different inlet-angle cases of air conditioners based on case studies, which were typically conducted during the facility design stage. Thereafter, we confirmed the influence of CHTC variations on thermophysiology and their contribution to the PMV calculation values. Although the analytical PMV results showed values outside of the application range (≤−3.0), they primarily fell within the normal range. Moreover, when the angle was set at 60° to project onto the floor, a difference of approximately 2 °C in the wall temperature was observed. This study forms the basis for further developing simulation models that aim to apply a coupled analysis method to future building designs.

Dynamic modelling of coastal aquaculture systems: A Review

Abstract Coastal aquaculture is an important economic activity in India dominated majorly by shrimp culture, which involves a range of interconnected processes that are challenging to analyse and optimise without a systematic approach. System dynamics modelling is a useful tool for understanding and predicting the behavior of complex coastal aquaculture systems. Here, we review the status of dynamic simulation modelling works undertaken in aquaculture, which can provide directives for various researchers working on developing simulation models for shrimp aquaculture. There is a need to assess the impact of dynamic forces on the animals during the culture period which could be addressed through these models. System dynamic models assist decision-makers to augment potential measures for aquaculture-related problems under different possible scenarios. System dynamic models developed in aquaculture were related to feeding, water quality parameters, nitrogen dynamics, growth, etc. The strengths and limitations of software packages used in developing the simulation models are discussed. Considering the economic potential of shrimp aquaculture, it is important to develop an integrated dynamic model for predicting all the sub-processes of shrimp aquaculture.

Разработка конструкции индуктора для закалки детали сложной формы

Due to active process of import substitution, domestic industry starts producing the parts previously purchased abroad. These parts are necessary for stable and reliable operation of various technical objects and systems. Thus, the development of a technological installation for hardening a metal profile is topical. The task is complicated by the fact that the profile has very thin irregularly shaped walls, which should be hardened only from the inside, while the outer wall of the profile should be heated minimally to maintain strength. The studies have been carried out on simulation models of electromagnetic and thermal fields, which make it possible to reproduce the process of induction heating of the research object. Since the part has the same shape along the entire length, the simulation of the process of its induction heating is performed in two-dimensional space. The authors have developed a simulation model of the process of induction heating of a part of a non-standard shape, which includes calculations of thermal and electromagnetic fields. The design of the inductor is proposed, supplemented with ferrite inserts, which makes it possible to achieve the temperature regime necessary for the hardening process. The developed simulation model makes it possible to evaluate the distribution of the thermal and electromagnetic fields of the part, thereby predicting getting the temperatures required for its hardening when using various designs of inductors. The results of numerical experiments are consistent with the physical concepts of induction heating and prove the possibility to use induction hardening for thin-walled parts of complex shape instead of laser hardening used for this type of parts. The proposed model can be used in engineering practice to design inductors of non-standard parts.