Existing Simulation Tools Research Articles

Simulation and Analysis Approaches to Microgrid Systems Design: Emerging Trends and Sustainability Framework Application

Energy systems modelling and design are a critical aspect of planning and development among researchers, electricity planners, infrastructure developers, utilities, decision-makers, and other relevant stakeholders. However, to achieve a sustainable energy supply, the energy planning approach needs to integrate some key dimensions. Importantly, these dimensions are necessary to guide the simulation and evaluation. It is against this backdrop that this paper focuses on the simulation and analysis approaches for sustainable planning, design, and development of microgrids based on clean energy resources. The paper first provides a comprehensive review of the existing simulation tools and approaches used for designing energy generation technologies. It then discusses and compares the traditional strategies and the emerging trends in energy systems simulation based on the software employed, the type of problem to be solved, input parameters provided, and the expected output. The paper introduces a practical simulation framework for sustainable energy planning, which is based on the social-technical-economic-environmental-policy (STEEP) model. The STEEP represents a holistic sustainability model that considers the key energy systems planning dimensions compared to the traditional techno-economic model used in several existing simulation tools and analyses. The paper provides insights into data-driven analysis and energy modelling software development applications.

Validation of a Numerical Model (Adytrack) Against Existing Simulation Tools and Field Measurements

Validation of a Numerical Model (Adytrack) Against Existing Simulation Tools and Field Measurements

Modeling and discretization of flow in porous media with thin, full‐tensor permeability inclusions

AbstractWhen modeling fluid flow in fractured reservoirs, it is common to represent the fractures as lower‐dimensional inclusions embedded in the host medium. Existing discretizations of flow in porous media with thin inclusions assume that the principal directions of the inclusion permeability tensor are aligned with the inclusion orientation. While this modeling assumption works well with tensile fractures, it may fail in the context of faults, where the damage zone surrounding the main slip surface may introduce anisotropy that is not aligned with the main fault orientation. In this article, we introduce a generalized dimensional reduced model which preserves full‐tensor permeability effects also in the out‐of‐plane direction of the inclusion. The governing equations of flow for the lower‐dimensional objects are obtained through vertical averaging. We present a framework for discretization of the resulting mixed‐dimensional problem, aimed at easy adaptation of existing simulation tools. We give numerical examples that show the failure of existing formulations when applied to anisotropic faulted porous media, and go on to show the convergence of our method in both two‐dimensional and three‐dimensional.

Guiding center and gyrokinetic orbit theory for large electric field gradients and strong shear flows

The guiding center and gyrokinetic theory of magnetized particle motion is extended to the regime of large electric field gradients perpendicular to the magnetic field. A gradient in the electric field directly modifies the oscillation frequency and causes the Larmor orbits to deform from circular to elliptical trajectories. In order to retain a good adiabatic invariant, there can only be strong dependence on a single coordinate at lowest order, so that resonances do not generate chaotic motion that destroys the invariant. When the gradient across magnetic flux surfaces is dominant, the guiding center drift velocity becomes anisotropic in response to external forces and additional curvature drifts must be included. The electric polarization density remains gyrotropic, but both the polarization and magnetization are modified by the change in gyrofrequency. The theory can be applied to shear flows that are even stronger than those observed in the edge transport barrier of a high-performance tokamak (H-mode) pedestal, even if the toroidal field is as small as or even smaller than the poloidal field. Yet, the theory retains a mathematical form that is similar to the standard case and can readily be implemented within existing simulation tools.

Developing Upscaling Approach for Swarming Hydraulic Fractures Observed at Hydraulic Fracturing Test Site through Multiscale Simulations

Summary This work aims to address a challenge posed by recent observations of tightly spaced hydraulic fractures in core samples from the hydraulic fracturing test site (HFTS) in the Middle Wolfcamp Formation. Many fractures in retrieved cores have subfoot spacing, which is at odds with conventional models in which usually one hydraulic fracture is initiated per cluster. Models assuming a single fracture at each cluster, although a common practice, often predict excessive fracture propagation that is inconsistent with microseismic observation. Here, we aim to develop a numerical approach to effectively account for densely spaced hydraulic fractures in field-scale simulations. Because it is impractical to explicitly model all aforementioned fractures, we develop a new upscaling law that enables existing simulation tools to predict reservoir response to fracture swarms. The upscaling law is derived based on an energy equivalence argument and validated through multiscale simulations using a high-fidelity code, GEOS. The swarming fractures are first modeled with a spacing that is much smaller than the cluster spacing; these fractures are then approximated by an upscaled, single fracture based on the proposed upscaling law. The upscaled fracture is shown to successfully match the energy input rate and produce the total fracture aperture and average propagation length of the explicitly simulated swarm. Afterward, the upscaling approach is further implemented in 3D field-scale simulations and validated against the HFTS microseismic data of a horizontal well. Our results show that hydraulic fracture swarming can significantly affect fracture propagation behaviors compared with the propagation of single fractures as assumed by conventional modeling approaches. Under the considered situations, the conventional treatment yields fast propagation speed that far exceeds that indicated by the microseismic data. We also illustrate that this discrepancy can be reduced readily through the implementation of the upscaling law. Our results demonstrate the importance of accounting for the fracture swarming effect in field-scale simulations and the efficacy of this approach to enable realistic predictions of reservoir responses to fracture swarms, without the need to model tightly spaced fractures individually.

Electrical and Thermomechanical Co-Simulation Platform for NPP

In order to analyze the safety of nuclear power plants (NPP), interactions between thermomechanical and automation processes, the on-site electrical grid, and the off-site transmission system should be studied in detail. However, an initial survey of simulation tools used for the modelling and simulation of NPP shows that existing simulation tools have some drawbacks in properly simulating the aforementioned interactions. In fact, they simulate detailed electrical power systems and thermomechanical systems but neglect the detailed interactions of the electrical system with thermomechanical and automation processes. To address this challenge, this paper develops an open-source co-simulation platform which connects Apros, a proprietary simulator of the thermomechanical and automation processes in NPP, to power system simulators. The proposed platform provides an opportunity to simulate both the electrical and thermomechanical systems of an NPP simultaneously, and study the interactions between them without neglecting any details. This detailed analysis can identify critical faults more accurately, and provides better support for probabilistic risk analyses (PRA) of NPP. To investigate the effectiveness of the proposed platform, detailed thermomechanical and electrical models of an NPP, located in Finland, are cosimulated. The preliminary results emphasize that neglecting the detailed interactions between domains of NPP may lead to inaccurate simulation results and may affect NPP safety.

AutoFrame: A Novel Procedure to Auto-Convert Architectural Massing Models into Structural Simulation Models to Streamline Embodied- and Operational-Carbon Assessment and Daylight Evaluation in Early Design

Sustainability and material efficiency are essential considerations in architecture. However, they are often evaluated late, absent optimization potentials inherent in architectural choices. Easy-to-use computational tools facilitate integration of performance parameters into design decision-making, but because different simulation environments require specific geometric input, simultaneous consideration of multiple constraints is not feasible without significant modeling. This research capitalizes on existing simulation tools and presents a novel procedure, AutoFrame, that converts architectural massing models into structural simulation input models to streamline daylight simulation, and embodied- and operational-carbon assessment during schematic design. Three reference buildings are used to validate the approach and a speculative case study demonstrates how the multi-disciplinary performance feedback guides design decisions while maintaining the flexibility of early design exploration.

Post-Processing Framework for Enhancing Liquid Surfaces in VFX Pipeline

Physically-based simulation is being expanded to simulate various materials such as deformable bodies, sand, and lava as well as liquid, and has been widely used as plug-in and software in actual related industries. Contrary to this trend, however, most of the simulation software products are built as an in-house solution, making it difficult for users to add new features not provided by the software. In this paper, we propose a post-processing framework that can improve the visual quality of liquid surfaces by receiving only the positions of liquid particles created in the existing simulation tools. Our framework includes the following methods: 1) analyzing liquid flow from particle position, 2) sampling technique for creating liquid sheets. Our framework improves the detail of liquid surfaces by temporarily adding new liquid particles through sampling of particles from existing simulation techniques. Our technique does not depend on any particular simulation tool. Experiments with various scenarios have also shown that liquid sheet detail, which was difficult to express in traditional software, has been improved, and problems such as break-up fluid surfaces and noisy surfaces have been mitigated. In addition, our research is a post-processing framework that uses only particle position as input data, making it easy to integrate with existing simulation tools that provide particle position.

Generating Name-Like Vectors for Testing Large-Scale Entity Resolution

Entity resolution (ER), the problem of identifying and linking records that belong to the same real-world entities in structured and unstructured data, is a primary task in data integration. Accurate and efficient ER has a major practical impact on various applications across commercial, security and scientific domains. Recently, scalable ER techniques have received enormous attention with the increasing need to combine large-scale datasets. The shortage of training and ground truth data impedes the development and testing of ER algorithms. Good public datasets, especially those containing personal information, are restricted in this area and usually small in size. Due to privacy and confidential issues, testing algorithms or techniques with real datasets is challenging in ER research. Simulation is one technique for generating synthetic datasets that have characteristics similar to those of real data for testing algorithms. Many existing simulation tools in ER lack support for generating large-scale data and have problems in complexity, scalability, and limitations of resampling. In our work, we propose a simple, inexpensive, and fast synthetic data generation tool. Our tool only generates entity names in the first stage, but these are commonly used as identification keys in ER algorithms. We avoid the detail-level simulation of entity names using a simple vector representation that delivers simplicity and efficiency. In this paper, we discuss how to simulate simple vectors that approximate the properties of entity names. We describe the overall construction of the tool based on data analysis of a namespace that contains entity names collected from the actual environment.

ИМИТАЦИОННОЕ МОДЕЛИРОВАНИЕ ПРОЦЕССОВ АГРЕГАТНО-СБОРОЧНОГО ПРОИЗВОДСТВА

The article presents a universal simulation model of aggregate and Assembly production processes based on IDEF0 methods and numerical modeling methods. The problem statement is formed as follows: it is necessary to analyze the existing simulation tools, structure the Assembly production processes into separate classes and subclasses, describe the processes using the IDEF0 method, create a simulation model of the aggregate-Assembly production process with a link between economic and labor costs. The total labor intensity of Assembly processes and economic costs were considered as optimization criteria in this study. Numerical modeling and optimization of workflow parameters were performed in the AnyLogic simulation environment. The obtained simulation models can be used in the future in the management system of aviation enterprises, as well as in other production areas where the product is a complex system.

A Kinetic Simulator For Distributed Mechanically Linked Marine Vehicles

Abstract The possibility of performing high-level simulations based on a kinetic model is an important step in the implementation of navigation, guidance, and control systems for marine robots. In the framework of the EUMR TNA project DINGOS, we strive to enhance a simulation tool under MATLAB/Simulink for the CNR catamaran-like vehicle SWAMP (Shallow Water Autonomous Multipurpose Platform) ASV. The vehicle can be separated into two hull vessels that can operate independently, but also with different physical connection between them (like fixed pole or rubber band). In the paper, we will describe the physical modelling of the different connection types in a 3DOF system, the implementation into the existing simulation tool for the whole vehicle, and show the results achieved in simulation runs where different connection types can be chosen and parameterized.

Lessons Learned in Leveraging Existing Simulations for Cybersecurity Training, Evaluation, and Research

We provide lessons learned in leveraging existing simulations to conduct human-subjects cybersecurity experiments and develop training for cybersecurity professionals. First, we provide criteria for the evaluation and categorization of existing simulation tools into four categories (competitions, testbeds, tabletop exercises, and simulations used in published research). Following this, eight criteria are offered to evaluate simulations on their suitability for use in experiments. We evaluated one representative product in each category. This paper serves as a resource for practitioners who use simulation as a method of training or evaluation. Further, this work is a starting point for researchers to efficiently find and leverage simulations to conduct cybersecurity research.

Signatures of secondary leptons in radio-neutrino detectors in ice

The detection of the radio emission following a neutrino interaction in ice is a promising technique to obtain significant sensitivities to neutrinos with energies above PeV. The detectable radio emission stems from particle showers in the ice. So far, detector simulations have considered only the radio emission from the primary interaction of the neutrino. For this study, existing simulation tools have been extended to cover secondary interactions from muons and taus. We find that secondary interactions of both leptons add up to 25\% to the effective volume of neutrino detectors. Also, muon and tau neutrinos can create several detectable showers, with the result that double signatures do not constitute an exclusive signature for tau neutrinos. We also find that the background of atmospheric muons from cosmic rays is non-negligible for in-ice arrays and that an air shower veto should be considered helpful for radio detectors.

An agent-based simulator for indoor crowd evacuation considering fire impacts

Fire emergencies impose significant threats to building occupants. During evacuation, fire has significant impacts on evacuees' behaviors, by e.g., changing their route availability, disturbing their perception of the environment due to reduced visibility, impairing their mobility that is usually associated with severe injuries, and causing significant mental stress that may lead to complicated and unpredictable navigation decisions. Despite the detrimental effects of fire on crowd evacuation, most existing building evacuation simulation models and tools do not account for the impacts of fire on the evacuation process; at most they rely on oversimplified assumptions and simulation settings. In this study, a new fire evacuation simulation model, named FREEgress (Fire Risk Emulated Environment for Egress), is developed to simulate the dynamic influences of heat, temperature, toxic gas and smoke particles on evacuees' mobility, navigation decision making and health conditions. FREEgress (1) introduces evacuee agents who are aware of and able to assess the fire hazards, and can make fire risk-informed navigation decisions; and (2) models the interactions between evacuee agents and the dynamic fire emergency environments and the consequent evacuation process. The verification of FREEgress is conducted by comparing its simulation results with two existing simulation tools, SAFEgress and FDS + Evac. In addition, a case study using FREEgress is carried out to simulate the evacuation in a museum for 30 different fire emergency scenarios. The simulation results are analyzed to assess the impacts of three important factors, namely initial fire location, evacuation delay time and evacuee behavior, on the evacuation process and evacuation outcomes. The case study demonstrated the potential value of FREEgress to support both the safety design of new buildings and maintenance and emergency management of constructed facilities.

Interpolation for power electronic circuit simulation revisited with matrix exponential and dense outputs

With a high penetration of power electronic equipment, transient simulation for power electronic circuit has been a main challenge for performance improvement of the electromagnetic transient simulation tools. In this paper, two new solvers for the matrix exponential-based simulation method are proposed based on the dense output formula and Padé approximation of different orders. The proposed solvers are implemented with the optimal combination of numerical integration method and interpolation method. Both solvers are L-stable. One has 3rd-order accuracy which is more accurate than existing simulation tools in power electronic simulation. The other solver achieves 1st-order accuracy with a lower precision numerical integration method than the same-order algorithms and is appealing from computation speed perspective. Numerical studies including TCR circuit and two types of VSC-HVDC systems are conducted to demonstrate the effectiveness of the proposed solvers.

Bayesian Inference in Snow Avalanche Simulation with r.avaflow

Simulation tools for gravitational mass flows (e.g., avalanches, debris flows) are commonly used for research and applications in hazard assessment or mitigation planning. As a basis for a transparent and reproducible decision making process, associated uncertainties need to be identified in order to quantify and eventually communicate the associated variabilities of the results. Main sources of variabilities in the simulation results are associated with parameter variations arising from observation and model uncertainties. These are connected to the measurement inaccuracies or poor process understanding and the numerical model implementation. Probabilistic approaches provide various theoretical concepts to treat these uncertainties, but their direct application is not straightforward. To provide a comprehensive tool, introducing conditional runout probabilities for the decision making process we (i) introduce a mathematical framework based on well-established Bayesian concepts, (ii) develop a work flow that couples this framework to the existing simulation tool r.avaflow, and (iii) apply the work flow to two case studies, highlighting its application potential and limitations. The presented approach allows for back, forward and predictive calculations. Back calculations are used to determine parameter distributions, identifying and mapping the model, implementation and data uncertainties. These parameter distributions serve as a base for forward and predictive calculations, embedded in the probabilistic framework. The result variability is quantified in terms of conditional probabilities with respect to the observed data and the associated simulation and data uncertainties. To communicate the result variability the conditional probabilities are visualized, allowing to identify areas with large or small result variability. The conditional probabilities are particularly interesting for predictive avalanche simulations at locations with no prior information where visualization explicitly shows the result variabilities based on parameter distributions derived through back calculations from locations with well-documented observations.

On the role of integrated computer modelling in fusion technology

• We analyse critically current capabilities and maturity levels of existing simulation tools relevant to fusion blanket physics and design. • The progress in the development of computational tools in each particular is found to be significant. • The requirements that need to be addressed for code integration are common to all areas and tools. • The integration into one single computational tool is currently premature and looser coupling ways need to be considered. Computer modelling is expected to play an increasingly important role in fusion design and technology, where the complexity of the physical processes involved (plasma, materials, engineering), and the highly interconnected nature of systems and components (“system of systems” design), call for support from sophisticated and integrated computer simulation tools. In this paper, we review the contribution of coupled computer modelling to the design of the reactor, breeding blanket and integrated first wall in terms of neutronics, materials behaviour (including plasma-materials interaction, radiation effects and compatibility with fluids), magnetohydrodynamics thermofluid issues and thermo-hydraulic aspects, as well as simulations of plasma transport out of the confinement region to determine heat and particle loads on plasma facing components. The current capabilities and levels of maturity of existing simulation tools are critically analysed, having in mind the possibility of integrating several tools in a single computational suite in the future and highlighting the perspectives and difficulties of such an endeavour.

Computational Tools for Modeling and Analysis of Power Generation and Transmission Systems of the Smart Grid

The traditional power generation and distribution systems will be supplanted by the Internet of Energy, which accelerates the necessity to know the appropriate computation tools to perform any research in this future smart grid arena. However, there is a plethora of computational tools in this area, which challenges the researchers to find an appropriate tool based on their research objectives. Therefore, this article presents a comprehensive study about existing simulation tools related to electrical power generation, transmission, distribution, and associated systems. It provides an overview of more than 150 simulation software in these areas. The tools are classified and discussed based on both traditional and CEN-CENELEC-ETSI smart-grid reference architecture. Typical applications, sources, availability, and strengths of each tool are listed. Each tool has its own strengths and limitations to perform a certain task, and necessary information are provided to help researchers to find an appropriate computational tool for their specific research goal.

Combined Alternate-Direction Lane Assignment and Reservation-Based Intersection Control

This paper presents a concept, herein called Combined Alternate-Direction Lane Assignment and Reservation-based Intersection Control (CADLARIC), for organizing directionally unrestricted traffic flows in automated vehicle environment. In the proposed concept, vehicles can use lanes traditionally reserved for the opposite direction of travel. This concept allows left and right turning vehicles to align themselves in an appropriate lane before reaching the downstream intersection, so that they can smoothly go through the intersection without having any conflicts with vehicles from the other movements. Conflicts between through movements are handled by a reservation-based algorithm. To simulate the proposed concept, i.e. allow flexibility of such driving maneuvers that cannot be accomplished in the other existing simulation tools, a new microsimulation platform is developed. The proposed CADLARIC control scheme is evaluated through a comparison with a conventional fixed-time signal control and Fully Reservation-Based Intersection Control (FRIC). The results show that CADLARIC: (i) significantly outperforms other control methods in terms of the traffic performance (i.e. delays and stops); and (ii) generates a reduction of conflicting situations at the network level when compared to FRIC.

Analysis of energy efficiency improvement of high-tech fabrication plants

Abstract In this study, we developed simulation software for the energy consumption of high-tech fabrication plants. The developed fab energy simulation (FES) featured more detailed characteristics of the subsystems than existing simulation tools. The calculated results of the FES were validated using the annual operating data of a Taiwanese semiconductor manufacturing fab. The measured data indicated three major energy consumers in the studied fab—the process tool, water chiller and clean dry air systems. The annual consumption of electricity calculated with the FES showed a deviation of only −0.73% compared with the measured data. The calculated results exhibited an energy consumption trend that was very similar to the measured data, indicating the reliability of the FES. The FES results also demonstrated excellent agreement with the calculated results of the commercial tool ‘CleanCalc II’. Additionally, the FES was employed to study the energy consumption under different conditions. The results revealed that the energy consumption of the chiller system reduced significantly by 43.7% when the chiller system with a coefficient of performance of 8 was used. This reduction in the energy consumption corresponded to 10% of the total energy consumption in the fab, indicating significant energy-saving potential.