Documents published in Scipedia

• Digitization Principles for Application Scenarios towards Digital Twins of Organizations

  A. Sumereder, R. Woitsch

  eccomas2022.

  
  

  Abstract

  In today's agile business ecosystems, digital twins (DTs) and especially digital twins of organizations (DTOs) allow for adaption through dynamically evolving models depicting organizational aspects such as production processes, data flows, human actors and interactions. A hybrid modelling approach is utilized, as the establishment of such DTOs either considered on their own or as part of a DT ecosystem is not trivial. Meta modelling and meta model merging patterns are applied to integrate heterogeneous perspectives and domain models. Two main research questions with respect to digitization towards digital twinning are discussed: First, which digitization principles/patterns are appropriate for DTOs? Patterns ranging from 'counting' to 'estimation' are introduced to fill digital models serving as a foundation for DTs with data. As a starting point, potential digitization principles for relevant characteristics of BPMN ­ 'Modelling Method for Business Processes' and KPI ­ 'Modelling Method for Key Performance Indicators' models are considered. Second, which principle/pattern is appropriate for which organizational structure? In order to ease the selection of suitable patterns for specific application scenarios, those will be associated with organizational structures like but not limited to construction processes, assembly processes or production processes each of them with domain-specific characteristics. A prototype consisting of three phases ­ use case requirements collection, model design and digitization assistance ­ builds upon (a) physical experimentations in the OMiLAB Innovation Corner using physical assets such as edge devices or sensors, (b) domain specific services considering software related aspects such as timeseries databases or simulation algorithms, and (c) modelling methods enabling the integration of physical and digital components. The paint production pilot from the European Change2Twin project serves as an application scenario evaluation use case. A notion of what the use case company intends to achieve by digital twinning and what is possible by introducing digital services is touched. The outlook presents how artificial intelligence may be introduced for the prototype to leverage the paint production use case and further application scenarios.

  Abstract
  In today's agile business ecosystems, digital twins (DTs) and especially digital twins of organizations (DTOs) allow for adaption through dynamically evolving models depicting [...]

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• A Data-Driven Reduced Order Modeling Approach Applied in Context of Numerical Analysis and Optimization of Plastic Profile Extrusion

  D. Hilger, N. Hosters

  eccomas2022.

  
  

  Abstract

  In course of this work, we examine the process of plastic profile extrusion, where a polymer melt is shaped inside the so-called extrusion die and fixed in its shape by solidification in the downstream calibration unit. More precise, we focus on the development of a data-driven reduced order model (ROM) for the purpose of predicting temperature distributions within the extruded profiles inside the calibration unit. Therein, the ROM functions as a first step to our overall goal of prediction based process control in order to avoid undesired warpage and damages of the final product.

  Abstract
  In course of this work, we examine the process of plastic profile extrusion, where a polymer melt is shaped inside the so-called extrusion die and fixed in its shape by solidification [...]

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• A Validation Program for Dynamic High-Lift System Aerodynamics

  J. Wild, H. Strüber, F. Moens, B. v.an Rooijen, H. Maseland

  eccomas2022.

  
  

  Abstract

  The feasibility of laminar flow control technology for future wing is bound to the development of a leading edge high-lift system that complies with the requirements on smooth surfaces to enable maintaining the laminar boundary layer flow, such as a Krueger flap. Although in principle the aerodynamic performance of a Krueger flap is known, the unsteady behaviour of the flow during deployment and retraction is completely unknown. This is as even more important as during deployment the Krueger flap is exposed to highly unfavourable positions perpendicular to the flow. To mitigate the risk of unfavourable aircraft behaviour, it is therefore expected that a Krueger flap has to be deflected significantly fast and may trigger unsteady aerodynamic effects. The European H2020 project UHURA, running from September 2018 to August 2022, has been focusing on the unsteady flow behaviour around such high-lift system and will first time deliver a deeper understanding of critical flow features at this type of high-lift device during their deployment and retraction together with a validated numerical procedure for its simulation. UHURA performed detailed experimental measurements in several wind tunnels to obtain a unique data set for validation purposes of Computational Fluid Dynamics (CFD) software, including detailed flow measurements by Particle Image Velocimetry (PIV) and other optical measurement technologies.

  Abstract
  The feasibility of laminar flow control technology for future wing is bound to the development of a leading edge high-lift system that complies with the requirements on smooth [...]

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• Krueger High-Lift System Design Optimization

  E. Iuliano, D. Quagliarella, J. Wild

  eccomas2022.

  
  

  Abstract

  This work describes the cooperative/competitive design process that led to the definition of the Krueger flap to be used in the numerical and experimental tests of the European project UHURA. The project requirements are particularly challenging because it is necessary to develop a device with good aerodynamic high-lift characteristics, but it is necessary to consider many constraints of structural and kinematic nature. Indeed, the kinematics for its deployment is quite complex and imposes hard constraints on the Krueger shape, and the structural characteristics must allow it to withstand considerable structural stresses in the deployment phase which is studied in the wind tunnel.

  Abstract
  This work describes the cooperative/competitive design process that led to the definition of the Krueger flap to be used in the numerical and experimental tests of the European [...]

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• Lattice Boltzmann simulation of a deploying Krueger device

  J. Ponsin, C. Lozano

  eccomas2022.

  
  

  Abstract

  In this paper, we describe the numerical simulations carried out within the H2020 UHURA project of the turbulent unsteady flow generated during the motion of a Krueger device for laminar wings using a commercial lattice Boltzmann solver based on a Wall-Modelled LES approach. The simulations are focused on reproducing one of the experimental test cases carried out in the ONERA-L1 wind tunnel during the UHURA project. The numerical method and the simulation setup are described. The simulation results are compared with the high-quality experimental data obtained in the ONERA-L1 wind tunnel in order to assess the accuracy of the predictions.

  Abstract
  In this paper, we describe the numerical simulations carried out within the H2020 UHURA project of the turbulent unsteady flow generated during the motion of a Krueger device [...]

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• Numerical investigation of Hydrogen self-ignition and deflagration-to-detonation phenomena using automated meshing approach and detailed chemistry

  M. Cojocaru, L. Sufrà, P. Scienza

  eccomas2022.

  
  

  Abstract

  Computational fluid dynamics (CFD) plays a critical role in designing safe storage and transport systems for hydrogen. Fine mesh resolution and detailed chemistry are essential for the accurate prediction of self-ignition and deflagration-to-detonation (DDT) in hydrogenair mixtures. However, simulating H2 venting and explosion in real-life scenarios (e.g., with complex obstacle shapes and a large computational domain) involves tedious meshing effort and several mesh iterations to capture flame and shock locations. This paper addresses these challenges by assessing the capability of a detailed-chemistry approach combined with automated meshing based on a cut-cell technique and Adaptive Mesh Refinement (AMR). Furthermore, three different turbulence-chemistry interaction modelling approaches are compared for self-ignition and DDT scenarios: a homogeneous reactor model, an eddy dissipation model, and a flame thickening approach.

  Abstract
  Computational fluid dynamics (CFD) plays a critical role in designing safe storage and transport systems for hydrogen. Fine mesh resolution and detailed chemistry are essential [...]

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• Finite element model of kurpsai dam in kyrgyzstan based on actual response measured by extensive network of various sensors

  S. Takhirov, S. Orunbaev, E. Toshmatov, R. Shamansurov, R. Shamansurov, Z. Baiyzbekov

  eccomas2022.

  
  

  Abstract

  The paper presents recent results of an ongoing collaborative research project focused on modelling the Kurpsai water dam in Kyrgyzstan. The research team includes scientists and engineers from the USA, Kyrgyzstan, and Uzbekistan. This water dam was selected for modelling because of the recent installation of an extensive network of various sensors aimed at monitoring its performance under seasonal changes, ambient vibration, and seismic excitation. The installed instrumentation network includes the following sensors: (1) a set of fiber-optic strainmeters and temperature meters, (2) a set of velocimeters for seismic monitoring, and (3) a set of GNSS receivers to measure absolute static displacements. A 3D model of the water dam was generated based on a utilization of the finite element approach. As a starting point the water dam’s concrete was assumed to be elastic material. The latter assumption is considered acceptable, because (as of today) only responses to relatively small excitations were measured by the sensors. The actual responses of the dam were compared to that of the finite element model to achieve a close correlation with each other. Resonant frequencies of the water dam and its vibrational modes were estimated from the model. In the next phase of the project, the research team is planning to update the geometry of the model based on laser scanning that will be conducted this year. Local anomalies (bulging areas, cracks and so on) of the water dam will be studied via an analysis of point clouds collected by the laser scanner. The fully developed model will be used in an extensive numerical study to predict the dam’s performance and its response to strong seismic events and other hazards.

  Abstract
  The paper presents recent results of an ongoing collaborative research project focused on modelling the Kurpsai water dam in Kyrgyzstan. The research team includes scientists [...]

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• Mathematical modeling and numerical results on the propagation of solitary waves on tensegrity lattices

  A. Amendola, F. Fraternali, G. Saccomandi

  eccomas2022.

  
  

  Abstract

  This work discusses the mathematical properties of the interaction potential that characterizes tensegrity mass-spring chains, and its implications in terms of the propagation of compact compression waves in such systems when impacted by a striker. Numerical simulations show evidence of the dependence of the wave form on the speed of the propagating compression pulses, which change shape when passing from the sonic to the super-sonic wave propagation regime.

  Abstract
  This work discusses the mathematical properties of the interaction potential that characterizes tensegrity mass-spring chains, and its implications in terms of the propagation [...]

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• Wear modelling in elasto-plastic wheel-rail contact problems

  A. Myśliński, A. Chudzikiewicz

  eccomas2022.

  
  

  Abstract

  The paper is concerned with the development of the numerical procedure to solve the wheel-rail contact problem and the computation of the distribution of surface flash temperatures, stresses as well as the wear evolution due to friction. The two-dimensional wheel-rail contact problem between a rigid wheel and an elasto-plastic rail lying on a rigid foundation is considered. The contact phenomenon includes Coulomb friction, frictional heat generation as well as the wear of the contacting surfaces. The displacement and stress of the rail in contact are governed by the coupled elasto-plastic and heat conductive equations. The wear depth function appears as an internal variable in the non-penetration condition updating the gap between the worn surfaces of the bodies. Moreover the dissipated energy due to friction is calculated to evaluate the loss of rail material and to determine the shape of the contacting surfaces during the wear evolution process. This contact problem is solved numerically using the finite element method as well as the operator splitting approach. The plastic flow and friction inequality conditions are reformulated as equality conditions using the nonlinear complementarity functions. The distribution of surface temperatures and stresses as well as the evolution of the shape of the contact surfaces and the wear depth are reported and discussed.

  Abstract
  The paper is concerned with the development of the numerical procedure to solve the wheel-rail contact problem and the computation of the distribution of surface flash temperatures, [...]

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• REDIM based model reduction of the decomposition of urea-water-solutions in films and droplets

  E. Berszány, M. Stein, V. Bykov, U. Maas

  eccomas2022.

  
  

  Abstract

  Selective catalytic reduction (SCR) process with urea-water solution (UWS) is often used in automotive industry to decrease emissions of nitric oxides (NO x) in the exhaust gas. In this process the urea from UWS decomposes to isocyanic acid and ammonia, where the latter is needed to increase the efficiency of the NO xreduction on the catalyst surface. Along with the advantages of using UWS several drawbacks reduce the performance of a SCR system. Incomplete decomposition of urea leads to a formation of residuals affecting the efficiency of the exhaust gas systems. Therefore, the complete decomposition of urea and homogeneous distribution of the resulting ammonia in front of the SCR catalyst represent main challenges in improving the SCR technology. In order to investigate the process of the urea decomposition a detailed chemical kinetic mechanism in the liquid phase is employed. The results are compared with a commonly used approach to model urea decomposition as an evaporation with a following decomposition reaction in the gas phase. It is shown that by using such a mechanism, the decomposition of urea and the gas phase composition with the urea decomposition products can be described more accurately. However, implementing these mechanisms in computations (in CFD approaches) requires a large amount of computational (CPU) time and memory. The method of Reaction Diffusion Manifolds (REDIMs) is implemented for the reduction of the detailed chemical kinetics in the stage of urea decomposition such that the distribution of products of the urea decomposition can be captured accurately in the gas phase with only two reduced variables instead of the 7 gas phase species of the original model.

  Abstract
  Selective catalytic reduction (SCR) process with urea-water solution (UWS) is often used in automotive industry to decrease emissions of nitric oxides (NO x) in the exhaust [...]

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