BES with FEM: Building Energy Simulation using Finite Element Methods

An overall objective of energy efficiency in the built environment is to improve building and systems performances in terms of durability, comfort and economics. In order to predict, improve and meet a certain set of performance requirements related to the indoor climate of buildings and the associated energy demand, building energy simulation (BES) tools are indispensable. Due to the rapid development of FEM software and the Multiphysics approaches, it should possible to build and simulate full 3D models of buildings regarding the energy demand. The paper presents a methodology for performing building energy simulation with Comsol. The method was applied to an international test box experiment. The results showed an almost perfect agreement between the used BES model and Comsol. These preliminary results confirm the great opportunities to use FEM related software for building energy performance simulation.Comment: 5 pages, 6 figures, Proceedings of the 2012 COMSOL Conference in Mila

The development of a mapping tool for the evaluation of building systems for future climate scenarios on European scale

The paper presents a tool for the mapping of the performance of building systems on European scale for different (future) time periods. The tool is to use for users and be applicable for different building systems. Users should also be able to use a broad range of climate parameters to assess the influence of climate change on these climatic parameters. Also should the calculation time be reasonable short. The mapping tool is developed in MATLAB, which can be used by other users for their own studies.Comment: 21 pages, 24 figures, pre-conferenc

Comsol Simulations of Cracking in Point Loaded Masonry with Randomly Distributed Material Properties

This paper describes COMSOL simulations of the stress and crack development in the area where a masonry wall supports a floor. In these simulations one of the main material properties of calcium silicate, its E-value, was assigned randomly to the finite elements of the modeled specimen. Calcium silicate is a frequently used building material with a relatively brittle fracture characteristic. Its initial E-value varies, as well as tensile strength and post peak behavior. Therefore, in the simulation, initial E-values were randomly assigned to the elements of the model and a step function used for describing the descending branch. The method also allows for variation in strength to be taken into account in future research. The performed non-linear simulation results are compared with experimental findings. They show the stress distribution and cracking behavior in point loaded masonry when varying material properties are used.Comment: Conference pape

Remaining lifetime modelling for replacement of power transformer populations

The age of the majority of power transformers applied in the western electricity network varies between 25 and 50 years. Depending on the load history and time of operation, replacement on short term is imminent. A technically sound policy concerning the replacement of these assets must be based on knowledge of (i) the life expectancy or reliability of individual components, (ii) how these failure probabilities cumulate to a replacement wave, and (iii) how to manage an expected replacement wave. The population reliability is obtained from individual transformer reliabilities using Arrhenius based modelling of paper insulation degradation. This modelling technique includes measures to cope with inherent uncertainties in available data. Population reliability figures are obtained using an adapted k-out-of-N failure model. The modelling method is applied to existing populations of power transformers in The Netherlands, to evaluate their expected replacement wave

Organization and Outcomes of Integrated Inpatient Medical and Psychiatric Care Units:A Systematic Review

Abstract Objective: The goal of this review was to assess the relationships among aims, designs, and outcomes of integrated inpatient medical and psychiatric care units (IMPUs) and gather the evidence base on the effectiveness of these units. Methods: Using online searches of Embase, Medline, Web of Science, PsycINFO, Scopus, CINAHL, Cochrane, and Google Scholar, the authors identified and reviewed literature describing the aims and outcomes of specific IMPU designs. Results: The search yielded 55 studies, in which the authors identified 39 IMPUs that focused on patients with mood, psychotic, somatic symptom, substance use, organic, and personality disorders and a broad array of medical diagnoses. Most units were psychiatric-medical units and had medium medical and psychiatric acuity capabilities. The studies reviewed provided little information on the cost-effectiveness of various IMPU designs. Although some comparative studies indicated reductions in hospital length of stay (LOS), these studies were generally of low quality and rarely reported other intended outcomes. Conclusions: IMPUs may help shorten LOS. IMPUs should focus care on patients with complex conditions and high acuity to maximize health system value. Implementing compulsory admission facilities; qualified psychiatric, medical, and nursing staff involvement; and cross-disciplinary training may improve IMPUs’ capacity to treat high-acuity patients. Future research should relate IMPU designs to intended outcomes

The multiphysics modeling of heat and moisture induced stress and strain of historic building materials and artefacts

The basic structure of historic sites and their associated interior artefacts can be damaged or even destroyed by climate change. The evaluation of combined heat and moisture induced stress and strain (HMSS) can predict possible damage-related processes. In this paper, the development of one- and two-dimensional HMSS models of building materials and artefacts in COMSOL Multiphysics Version 4, a commercial finite element software, is presented. The validation of the numerical models is revealed using analytical, numerical and experimental solutions. As a result, the HMSS model was shown to be an adequate predictive tool to determine possible damage-related processes in building assemblies and artefacts