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Influence of breach parameter models on hazard classification of off-stream reservoirs

水科学与水工程 2025年第1期18卷 102-114页

作者： Nathalia Silva-Cancino Fernando Salazar Ernest Bladé Marcos Sanz-Ramos International Centre for Numerical Methods in Engineering(CIMNE) Barcelona 08034Spain International Centre for Numerical Methods in Engineering(CIMNE) Barcelona 08034Spain Flumen Institute Universitat Politècnica de Catalunya-CIMNEBarcelona 08034Spain Flumen Institute Universitat Politècnica de Catalunya-CIMNEBarcelona 08034Spain

The classification of dams or off-stream reservoirs concerning potential hazards in the event of failure often involves the use of two-dimensional hydraulic models for computing floodwave *** models necessitate defining breach geometry and formation time,for which various parametric models have been *** models yield different values for average breach width,time of failure,and consequently,peak flows,as demonstrated by several *** study analyzed the effect of selecting a breach parametric model on the hydraulic variables,potential damages,and hazard classification of *** common parametric models were compared using a set of synthetic cases and a real off-stream *** indicated significant effects of model *** erodibility exerted a significant impact,surpassing that of fail-ure *** factors,such as the Manning coefficient,significantly affected the *** an inadequate model or lacking information on dike material can lead to overly conservative or underestimated outcomes,thereby affecting hazard classification.

关键词： Dam breach Off-stream reservoir Hazard classification Flooding Potential damages

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A Comparative Review of FEM Like Techniques Applied to the Linear Analysis of Molecular Structures

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Archives of Computational methods in engineering 2025年 1-28页

作者： Fernández-San Miguel, Andrés Ramírez, Luis Couceiro, Iván Navarrina, Fermín Group of Numerical Methods in Engineering-GMNI Center for Technological Innovation in Construction and Civil Engineering-CITEEC Civil Engineering School Universidade da Coruña Campus de Elviña A Coruña15071 Spain

In this study, a historical review of the Finite Element Method (FEM) and Molecular Dynamics (MD), widely used at the macro and nanoscale respectively is presented, emphasizing the actual parallelisms between their development and applications. After this historical introduction, where certain similarities between both methods are pointed out, different FEM-like methods are analyzed and compared as for first order analysis of structures at the nanoscale. Firstly, the Structural Mechanics (SM) approach is analyzed, where it is assumed that the use of Euler Bernoulli beam elements is equivalent to working directly from the force field. On the other hand, the Molecular Element Method (MEM), which provides the stiffness matrices directly from the potentials, is analyzed. Several analytical static cases are studied for the validation and comparison of both methods. Finally, it is shown that, other branch of methods such as Elastic Network Models (ENM) can be viewed as a particular sub-case of the MEM, or as truss-type finite elements. As an example, the analysis of SARS-CoV2 spikes vibrations is included, comparing with both experimental results and continuous models. © The Author(s) 2025.

关键词： Stiffness matrix

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An Open-Source Approach for a Seamless BIM-GIS Integration 20th

An Open-Source Approach for a Seamless BIM-GIS Integration

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20th International Conference on Computing in Civil and Building engineering, ICCCBE 2024

作者： Xia, Zhongxin Kandler, Benedikt Schmidt, Jakob Volland, Vivien Mosler, Pascal Eichhorn, Andreas Rüppel, Uwe Institute of Numerical Methods and Informatics in Civil Engineering Technical University of Darmstadt Darmstadt Germany Institute of Geodesy Technical University of Darmstadt Darmstadt Germany

ISBN: (纸本)9783031842078

With global climate change and the progressing digitization of infrastructural projects, the BIM (Building Information Modeling)-method has become increasingly significant. For planning and managing BIM projects, GIS data is crucial, e.g., in the form of environmental data. Especially for large-scale infrastructure projects, integrating BIM models and GIS (Geographic Information System) data provides advantages. With an information-rich platform that aggregates geographic and infrastructural design information to provide geometric 3D visualization combined with semantic information, processing infrastructural projects can be simplified. Many integrated solutions require complex algorithms and additional manual work for converting and visualizing BIM models. This process potentially leads to the loss of model information or contradictory data. In addition, commercial software is required. We present a new approach for the BIM-GIS integration based on open-source frameworks. Various types of BIM and GIS files can be uploaded to the application. The files are unified in one 3D environment with absolute reference, for which the coordinate reference system of each file is temporarily converted to a user-definable coordinate reference system within the backend. The original files remain unchanged, so the application serves as a viewer and allows the user to view all geographical and infrastructural information. Furthermore, various tasks like coordinate transformation and geometric measurement can be performed. Besides the viewer functionality, the application enables users to annotate the data and provide feedback on the issues found in the BIM models. That allows various stakeholders to share their insights, which is crucial for managing infrastructural projects and seamlessly displaying BIM models and GIS data. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Climate change

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Sensitivity of Laminar Separation to Geometric Uncertainties

Sensitivity of Laminar Separation to Geometric Uncertainties

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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Tangermann, Eike Dierl, Wolfgang Klein, Markus Numerical Methods in Aerospace Engineering University of the Bundeswehr Munich Neubiberg85577 Germany Fluid Dynamics and Aerodynamics University of the Bundeswehr Munich Neubiberg85577 Germany

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

Within the present work, the process of laminar separation is investigated with respect to uncertainties of the geometric setup. It is well known, that the results from different experimental studies with a comparable setup show a range of variations depending on many factors of the specific case. Some of these factors can be attributed to variations of the model geometry. Therefore, numerical flow simulations with a well defined SD7003 wing geometry have been performed in order to quantify the sensitivity of the flow to two different factors, namely deviations of the wing surface and deviations of the angle of attack. For the first case, results are compared from an ideal wing and one based on a measured experimental model. Results from the corresponding experiment are featured as well for a comprehensive comparison. It will be shown that for low angles of attack with a larger region of laminar flow the impact is significant, whereas it decreases drastically at slightly higher angles of attack with a smaller laminar zone. Finally, simulation results for slight variations of the angle of attack show that these also have an impact to the flow especially at low angles of attack. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Laminar flow

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Structural degradation assessment of a preheater tower in a cement plant in Peru

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Case Studies in Construction Materials 2025年 22卷

作者： Barboza, Paula Martinelli, Enzo Etse, Guillermo Department of Civil Engineering University of Salerno Italy Center for Numerical and Computational Methods in Engineering National University of Tucuman Argentina

This article examines the structural behavior of a paradigmatic case in the cement industry: an existing reinforced concrete (RC) Preheater Tower (PT). The study focuses on assessing the degradation caused by the severe operational conditions of these industrial facilities and evaluating the consequent impact on structural safety. PTs are defined by their considerable total and inter-platform heights, substantial live loads on all platforms and prolonged exposure to high temperatures from the clinker preheating process. These factors pose significant structural challenges in ensuring long-term safety. Unlike previous studies, this research provides a more comprehensive analysis by investigating scenarios that are likely to occur throughout the lifecycle of critical industrial structures like PTs. Through in situ non-destructive dynamic tests conducted on all platforms and detailed finite element (FE) modeling, a rigorous calibration process was carried out to match observed vibration frequencies at different levels. The obtained parameters were then compared with the mechanical properties of concrete after long-term exposure to elevated temperatures. The analysis reveals that PTs in the cement industry undergo significant degradation due to prolonged exposure to medium and high temperatures. This concern is particularly critical in high-seismic-risk zones and in cases where inadequate maintenance results in the loss of necessary thermal insulation in cyclones and ducts—especially the platform over the kiln, which is the most vulnerable to high temperature exposure. Overall, this study establishes a reliable methodology for evaluating PTs safety by integrating on-site vibration analysis, FE structural modeling, and predictive modeling for PT under frequent seismic events. © 2025 The Authors

关键词： Cements

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Gaussian behaviors: representations and data-driven control

arXiv

引用

arXiv 2025年

作者： Sasfi, András Markovsky, Ivan Padoan, Alberto Dörfler, Florian Department of Information Technology and Electrical Engineering ETH Zürich Zürich8092 Switzerland Catalan Institution for Research and Advanced Studies Barcelona08010 Spain International Centre for Numerical Methods in Engineering Barcelona08034 Spain Department of Electrical & Computer Engineering University of British Columbia Canada

We propose a modeling framework for stochastic systems based on Gaussian processes. Finite-length trajectories of the system are modeled as random vectors from a Gaussian distribution, which we call a Gaussian behavior. The proposed model naturally quantifies the uncertainty in the trajectories, yet it is simple enough to allow for tractable formulations. We relate the proposed model to existing descriptions of dynamical systems including deterministic and stochastic behaviors, and linear time-invariant (LTI) state-space models with Gaussian process and measurement noise. Gaussian behaviors can be estimated directly from observed data as the empirical sample covariance under the assumption that the measured trajectories are from independent experiments. The distribution of future outputs conditioned on inputs and past outputs provides a predictive model that can be incorporated in predictive control frameworks. We show that subspace predictive control (SPC) is a certainty-equivalence control formulation with the estimated Gaussian behavior. Furthermore, the regularized data-enabled predictive control (DeePC) method is shown to be a distributionally optimistic formulation that optimistically accounts for uncertainty in the Gaussian behavior. To mitigate the excessive optimism of DeePC, we propose a novel distributionally robust control formulation, and provide a convex reformulation allowing for efficient implementation. © 2025, CC BY.

关键词： Stochastic systems

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A finite element enthalpy technique for solving coupled nonlinear heat conduction mass diffusion problems with phase change

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INTERNATIONAL JOURNAL OF numerical methods FOR HEAT & FLUID FLOW 1995年第10期5卷 907-921页

作者： McAdie, RL Cross, JT Lewis, RW Gethin, DT Institute for Numerical Methods in Engineering University of Wales Swansea UK Institute for Numerical Methods in Engineering University of Wales Swansea UK

A rigorous Finite Element (FE) formulation based on an enthalpy technique is developed for solving coupled nonlinear heat conduction/mass diffusion problems with phase change. The FE formulation consists of a fully coupled heat conduction and solute diffusion formulation, with solid-liquid phase change, where the effects of pressure and convection are neglected. A full enthalpy method is employed eliminating singularities which result from abrupt changes in heat capacity at the phase interfaces. The FE formulation is based on the fixed grid technique where the elements are two dimensional, four noded quadrilaterals with the primary variables being enthalpy and average solute concentration. Temperature and solid mass fraction are calculated on a local level at each integration point of an element. A fully consistent Newton-Raphson method is used to solve the global coupled equations and an Euler backward difference scheme is used for the temporal discretization. The solution of the enthalpy-temperature relationship is carried out at the integration points using a Newton-Raphson method. A secant method employing the regula falsi technique takes into account sudden jumps or sharp changes in the enthalpy-temperature behaviour which occur at the phase zone interfaces. The Euler backward difference integration rule is used to calculate the solid mass fraction and its derivatives. A practical example is analysed and results are presented.

关键词： finite element heat conduction diffusion phase change enthalpy method

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THE SUPERCONVERGENT PATCH RECOVERY (SPR) AND ADAPTIVE FINITE-ELEMENT REFINEMENT

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COMPUTER methods IN APPLIED MECHANICS AND engineering 1992年第1-3期101卷 207-224页

作者： ZIENKIEWICZ, OC ZHU, JZ Institute of Numerical Methods in Engineering Swansea UK

The error estimation processes which have been developed by the authors depend on the accuracy with which stresses (gradients) can be recovered. The recovery methods available currently, such as the L2 projection and averaging, are inaccurate and an improved process is needed. This paper presents a very much improved recovery process yielding superconvergent values throughout the domain. Details of this method, named the superconvergent patch recovery, are presented with test results showing its efficiency. Examples of adaptive, h-based refinement are given, showing high local and overall efficiency indices for error estimation.

关键词： numerical methods

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MESH GENERATION FOR AEROSPACE APPLICATIONS

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SADHANA-ACADEMY PROCEEDINGS IN engineering SCIENCES 1991年第1期16卷 1-45页

作者： WEATHERILL, NP Institute for Numerical Methods in Engineering University College of Swansea Swansea UK

In recent years there has been much research activity in the field of compressible flow simulation for aerodynamic applications. In the 1970's and 1980's the advances in the numerical solution of the Full Potential and Euler equations made, in principle, the inviscid flow simulation around complex aerodynamic shapes possible. At this stage much attention was focused on methods capable of generating meshes on which such calculations could be performed. In this paper an overview is presented of some techniques which have been developed to generate meshes for aerospace applications. Structured mesh generation techniques are discussed and their application to complicated shapes utilising the multiblock approach is highlighted. Unstructured mesh generation methods are also discussed with particular emphasis given to the Delaunay triangulation method. Finally, the advantages and disadvantages of the structured and unstructured approaches are discussed and new work is presented which attempts to utilise both these approaches in an efficient and flexible manner.

关键词： STRUCTURED MESH GENERATION UNSTRUCTURED MESH GENERATION INVISCID FLOW SIMULATION MESHES FOR AEROSPACE APPLICATIONS DELAUNAY TRIANGULATION METHOD COMPUTATION FLUID DYNAMICS

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A POINT ENRICHMENT STRATEGY FOR POLYGONAL FINITE VOLUME MESHES

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APPLIED MATHEMATICAL MODELLING 1992年第11期16卷 562-575页

作者： EVANS, A MARCHANT, MJ WEATHERILL, NP SZMELTER, J NATAKUSUMAH, DK Institute for Numerical Methods in Engineering University College of Swansea Swansea UK

A data structure based on edges for adaptive point enrichment or h refinement of structure an unstructured polygonally discretized domains is presented. The technique features both general and directional enrichment of quadrilateral and triangular elements and point removal. The method is demonstrated with the adaptive solution of the Euler equations for inviscid compressible flows on various aerofoil configurations, which clearly show the effectiveness of an adaptive point enrichment strategy in improving the quality of a flow simulation.

关键词： FINITE VOLUME methods ADAPTIVITY POINT ENRICHMENT CFD

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