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1113 research outputs found
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Requirements-based, early stage Architecture Performance Validation on a Brake System Use Case
Full text linkAutomotive industry OEMs and suppliers are progressing their engineering processes and performance to the next maturity level gearing to digital thread solutions. Current challenges like continuous engineering, virtual certification, distributed development, consolidated virtual proving grounds, homologation, digital twin and operational applications, require well informed decision making in a comprehensive, reliable, traceable and customizable environment. In particular, in automotive domain, with widespread tight collaborative ecosystems between integrators and suppliers, the capability of tracing each decision and its underlying artifacts becomes a key value of an engineering platform. This paper will outline a middleware approach to reuse generated artifacts and their relationships in a federated engineering environment and applying Modelica simulation models as the key integrator between architectural decision making and subsequent development up to detailed 3D design. Based on an exemplary, automotive brake system setup, the benefits of integrated data and workflows from specification to virtual architecture exploration and design verification are highlighted to motivate their value towards a realization of continuous model-based systems engineering methodologies
A Study on Model-Based Thermal Management Systems Architecture Modeling and Energy Efficiency Prediction of Fuel Cell Electric Vehicles
Full text linkThe purpose of this study is to predict the energy efficiency of Fuel Cell Electric Vehicles (FCEVs) based on the configuration of the Thermal Management System (TMS). The energy efficiency of an FCEV is closely tied to the effective thermal management of the electric powertrain. Therefore, this paper investigates TMS modeling for FCEVs and multi-physics modeling of FCEVs. The main modules of the target multi-physics FCEV model include the vehicle dynamics model, thermal management system, electric powertrain and controller. The main research focus is the water-cooled TMS architecture. The main thermal management components (heat-generating components) include the fuel cell, battery, motor and BOP (Balance of Plant). The model was developed using Modelica and used to predict the energy efficiency under various driving conditions (extremely cold, moderate and extreme heat) and driving conditions
Word Rain as a Service: Making semantically structured word clouds available to everyone
Full text linkThe Word Rain text visualisation technique is a novel approach to the classic word cloud that uses word embeddings to make the visualisation useful for exploring the word content of a text or corpus. Downloading and running code for generating word rain visualisations can, however, be prohibitively difficult or cumbersome for non-technical users and for casual evaluation. These use cases would consequently benefit greatly from a streamlined interface. We have therefore collected everything needed for generating word rain visualisations in a web-based service, and made it available as a SWELANG CLARIN K-centre resource. The web service, as well as the code for generating word rains, is made available as open source. The web service is deployed at: https://wordrain.isof.se
Implicit Unit Conversion in Modelica
Full text linkThere are many situations in which a Modelica model needsto handle quantities which are not expressed in the oftenpreferred unscaled SI units. Applying correct unitconversions is extremely important in such situations, andthe risk of human error needs to be mitigated usingunit-aware technology. Considering the power of unitchecking mechanisms in several Modelica tools today, onecan be surprised that unit conversion in Modelica stillneeds to be performed using error-prone user-writtenformulas and functions. It is demonstrated how automaticand implicit unit conversion can be introduced in Modelica,and that this can be done safely. The benefits of thisapproach are illustrated in a variety of examples andapplications
A Generic Non-Miscible Liquid-Gas Medium Model in Modelica with Analysis of Incompressibility Assumptions
Full text linkMotivated initially by the specific needs of Small ModularReactors (SMR) transient analysis, including Molten SaltReactors (MSR) draining or leak scenarios, or SodiumNatural Circulation Reactor (SNCR) scenarios, this paperpresents the development of a generic two-substanceliquid-gas medium and an approach used for a liquid Sodiummedium. Such media have a low isothermal compressibility,which is a key issue for the numerical robustness of thesimulation. These media are designed for compatibility withstandard libraries like Modelica.Fluid. We detail theirformulation, capabilities, and limitations. A significantportion of the paper is then dedicated to investigating acrucial aspect arising in such models: the representationof the liquid phase’s compressibility. We compare differentapproaches, analyzing their impact on the resultingequation system structure and numerical robustness usingthe OpenModelica debugger. This analysis demonstrates thetrade-offs involved and provides insights into selectingappropriate liquid models for dynamic simulations involvingnon-miscible flows
Modelling and Impact of Hydraulic Short Circuit Operation in Pumped Hydro Energy Storage
Full text linkThis paper investigates the hydraulic short circuit (HSC)operation of pumped hydro energy storage systems,specifically how it can be modelled and its impact onenergy capacity, efficiency and operating range. Hydraulicshort circuit operation enables power modulation duringcharging for fixed-speed pumped hydro systems, therebyallowing them to operate more flexibly. In this work, apumped hydro storage system with 140.5 MW nominal chargingpower and 10 h nominal charging time is analysed. Thestorage is simulated via a dynamic, system-level modelcomposed of detailed physical component models toaccurately depict the HSC operating behaviour. HSC enablespart-load operation from 39 MW to 107 MW but withsignificantly lower overall system efficiencies. The HSCoperating limits are governed by the turbine's minimum flowand maximum power. The custom-built OpenModelica libraryemployed for this analysis can be downloaded fromhttps://github.com/ibeyers/pumped-storage-analysis
Further Application of Modelica-Based Nuclear Power System Simulation: Tasks in Different Scenarios Driven by Model and Data
No full textSystem simulation is inherently an applied technology,driven by specific application demands. The Modelicalanguage enables equation-based, system-level,multi-domain, and visual modeling, facilitating researchersconducting system simulation studies of nuclear powersystems. This paper introduces the custom-built AESElibrary on the OpenModelica platform. Examples in AESE areprovided to illustrate the development and simulation ofsystem models for conventional pressurized water reactors(PWRs) and high-temperature gas-cooled reactors (HTGRs).The paper also describes tasks completed under differentapplication scenarios, including hardware-in-the-loopsimulation, multi-objective optimization, systemidentification, and rapid optimization, using model-drivenand data-driven approaches with the AESE library. Thefurther application of simulation models and data hassignificant practical and engineering value. This paperserves as a valuable reference for the intelligentapplication of energy system models in the context ofadvanced engineering challenges
CDL-PLC translator: From Modelica HVAC control design to IEC 61131 PLC implementation
Full text linkThis paper presents the CDL-PLC translator, a tool toconvert control sequences for building heating,ventilation, and air conditioning (HVAC) systems expressedin a subset of Modelica called Control Description Language(CDL) which is undergoing standardization via the voluntaryASHRAE Standard 231P into the IEC 61131-10 XML format. Sucha translation is a step in a model-based design workflowand contributes to digitalizing the control deliveryprocess in the building sector. The translation into theIEC 61131-10 XML is the last step in the implementation ofcontrol logic developed in CDL on programmable logiccontrollers (PLCs) standardized in IEC 61131. The paperpresents the details of the translator, an example for thevalidation of a CDL block vs. the corresponding IEC block,and a practical application example for the translation ofa control sequence for a hybrid heat pump plant from a casestudy neighborhood in Belgium. Practical applications, usecases, and future developments are discussed in the contextof building industry processes