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See detailNumerical modelling of two-way reinforced concrete slabs in fire
Lim, Linus; Buchanan, Andrew; Moss, Peter et al

in Engineering Structures (2004), 26(8), 1081-1091

This paper describes numerical modelling of the fire behaviour of two-way reinforced concrete slabs using a special purpose non-linear finite-element program, SAFIR. Several two-way reinforced concrete ... [more ▼]

This paper describes numerical modelling of the fire behaviour of two-way reinforced concrete slabs using a special purpose non-linear finite-element program, SAFIR. Several two-way reinforced concrete and composite steel-concrete slabs are tested under exposure to the ISO standard fire in order to validate the shell finite element in the SAFIR program. The modelling results showed agreement with the fire tests and demonstrate that the SAFIR shell element can be used to predict tensile membrane behaviour of two-way reinforced concrete slabs in fire conditions. The analyses show that two-way slabs have excellent fire resistance if they deform in double curvature and develop tensile membrane action. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailNumerical modelling of weathering at the catchment scale
Godderis, Y.; François, Louis ULg; Probst, A. et al

in Geochimica et Cosmochimica Acta (2004), 68(11), 425-425

Detailed reference viewed: 12 (1 ULg)
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See detailNumerical modelling with Wolf2D of the sedimentation problem at the entrance of a lock on the river Meuse
Khuat Duy, Bruno ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Dick, Erik; Hogge, Michel; Van Keer, Roger (Eds.) Proceedings of the 3rd International Conference on Advanced Computational Methods in Engineering (2005)

This paper presents the resolution of a practical hydraulic engineering problem thanks to effective numerical tools. A sedimentation study of the lock of Hun (river Meuse, Belgium) is completed using ... [more ▼]

This paper presents the resolution of a practical hydraulic engineering problem thanks to effective numerical tools. A sedimentation study of the lock of Hun (river Meuse, Belgium) is completed using solid transport models integrated in a finite volume free surface flows solver. The silting of the lock entrance is successfully modelled and various layout modifications of the site are tested to predict their effects and to see to what extent they could improve the actual situation. The analysis of the results shows that a regular dredging of the lock entrance is ineluctable. [less ▲]

Detailed reference viewed: 53 (3 ULg)
See detailNumerical Optimization Methods for Large Scale Problems
Fleury, Claude ULg

Conference given outside the academic context (2007)

Detailed reference viewed: 9 (0 ULg)
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See detailNumerical optimization of an injection volumetric expander for use in waste heat recovery organic Rankine cycle
Declaye, Sébastien ULg; Quoilin, Sylvain ULg; Lemort, Vincent ULg

in Proceedings of the 7th International Conference on Compressors and their Systems (2011, September 05)

Waste heat recovery organic Rankine cycle (ORC) systems allow generating mechanical or electrical power from local low grade heat sources. This paper shows how the power produced by the system can be ... [more ▼]

Waste heat recovery organic Rankine cycle (ORC) systems allow generating mechanical or electrical power from local low grade heat sources. This paper shows how the power produced by the system can be increased by achieving several evaporating pressure levels and injecting low pressure flow during expansion. A numerical model of the vapour injection expansion is developed and different system configurations are compared. In comparison with a simple configuration of the cycle, vapour injection configuration yields a maximum increase of 16% of the power production. Moreover, the specific power can be increased by 26%, which would largely reduce the specific investment cost of the waste heat recovery system. [less ▲]

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See detailNumerical post failure methods in multiphysical problems
Collin, Frédéric ULg; Levasseur, Séverine ULg; Chambon, René

in European Journal of Environmental and Civil Engineering [=EJECE] (2009), 7-8

Rupture in geomaterials is often preceded by a localization of the deformations within thin bands. The strain localization is thus an important process, which has been studied both experimentally and ... [more ▼]

Rupture in geomaterials is often preceded by a localization of the deformations within thin bands. The strain localization is thus an important process, which has been studied both experimentally and theoretically. This paper summaries main observations on localized phenomena and proposes theoretical and numerical tools to characterize localization processes. To deal with interactions occurring between the different phases of porous media, a regularization technique based on the second gradient model has been extended to multiphysic couplings. [less ▲]

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See detailNumerical predictions of the performance in flight of an air-breathing hypersonic vehicle: HyShot II
Iaccarino, Gianluca; Pecnik, Rene; Terrapon, Vincent ULg et al

in Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition; No IMECE2010-40186 (2010, November)

The uncertainties inherent to the operating conditions of the Hyshot II scramjet flight test are assessed. In particular, the variability of the pressure prediction in the combustor due to uncertain free ... [more ▼]

The uncertainties inherent to the operating conditions of the Hyshot II scramjet flight test are assessed. In particular, the variability of the pressure prediction in the combustor due to uncertain free stream conditions is investigated using a probabilistic methodology based on stochastic collocation. The uncertainties in Mach number, angle of attack and flight altitude are inferred from pressure measurements in the unfueled combustor using a Bayesian inversion approach. The forward computation relies on a reduced order model that represents the combustion processes in the scramjet combustor. A ground based experimental data set obtained from 1-to-1 model of the HyShot II vehicle with well defined operating conditions is used to validate the non-reacting solver and to calibrate the heat release model for the reacting combustor. The model prediction agrees well with the experimentally acquired flight data. On the other hand, our estimated flight free stream conditions differ from previously published results. [less ▲]

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See detailNumerical Procedure for Calculation of Temperature Evolution in Composite Elements with Internal Cavities
Luycks, Pierre; Stienon, P.; Franssen, Jean-Marc ULg et al

in Communications in Numerical Methods in Engineering (1994), 10(6), 437-451

In the paper a computation code based on the finite-element method for temperature evolutions in composite elements with internal cavities is presented. It is suitable for the analysis of various thermal ... [more ▼]

In the paper a computation code based on the finite-element method for temperature evolutions in composite elements with internal cavities is presented. It is suitable for the analysis of various thermal problems encountered in mechanical and civil engineering such as fire risk assessment. It is based on a plane isoparametric triangular element with six nodes allowing the modelling of curved boundaries. In order to analyze composite steel-concrete elements and to take into account the non-linearities coming from the temperature-dependent material properties and from the boundary conditions, an implicit integration scheme is used. Another advantage of the program is the possibility of describing internal cavities with convection and radiation exchanges. In order to show the capacity of the program two examples are presented. Comparisons have been made with experimental and other numerical results, exhibiting very good agreement. [less ▲]

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See detailNumerical processing of calculated echograms to derive stable room acoustics parameters
Embrechts, Jean-Jacques ULg

in Proceedings of the 104th Convention of the Audio Engineering Society, Convention paper nb. 4656 (1998)

Detailed reference viewed: 14 (4 ULg)
See detailNumerical Recipes - The Art of Scientific Computing -- W. H. Press et al.
Manfroid, Jean ULg

in Ciel et Terre (1987), 103

Not Available

Detailed reference viewed: 17 (3 ULg)
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See detailNumerical schemes for tracer studies in shallow shelf seas
Mercier, Christophe ULg

Doctoral thesis (2012)

Nowadays, tracers have revealed to be an invaluable integrated tool to investigate the different thematics related to coastal areas, shallow shelf seas or estuaries. In this work, they are used in ... [more ▼]

Nowadays, tracers have revealed to be an invaluable integrated tool to investigate the different thematics related to coastal areas, shallow shelf seas or estuaries. In this work, they are used in combination with a parallel scalable Fortran90 implementation of a 3D hydrodynamic model to study the transport of mud within the Belgian Coastal Zone. The results obtained illustrate the need for tools to understand the interactions between such highly energetic coastal areas and the sediment dynamics. The Constituent Age and Residence time Theory (CART), originally applied to passive tracers, is therefore extended to describe the sediments and used to quantify their rates of resuspension and horizontal transport. This application reveals some numerical issues that may degrade the reliability of the results. The different numerical parameterizations are thus revisited starting with the use of advection schemes, and especially, the Total Variation Diminishing (TVD) schemes built along the line defined by Harten. It is shown that the blind application of the usual TVD schemes and associated flux limiters can lead to non-TVD solutions when applied to complex geometries. Spatial and/or temporal variations of the bathymetry can indeed break the TVD property. Hopefully, really TVD schemes can be recovered by taking these variations into account in the formulation of the flux limiters. Even if its Eulerian formulation eases the implementation of CART into existing models, it is shown that CART's computation procedure lacks a numerical framework for a robust application. To address this, we enforce the consistency, defined as the requirement that the integration scheme does not introduce errors in the age field when aging is the only active process. Unfortunately, this does not guarantee the absence of overshootings. While it does not seem feasible to ensure a TVD behavior of the age field, appropriate modifications of the flux/slope limiters are derived here to prevent the occurrence of age values outside the physically acceptable range. On the bases of the solutions obtained after the advection of any numbers of tracers using high-order non-linear schemes, several control or global variables can be built. Even if the independent advection schemes used are specifically built to produce profiles free from the numerical artifacts that can spoil the physical meaning of the results, such global/control variables can exhibit these unwanted behaviors. This problematic is firstly treated with regard to the TVD schemes built from Harten's theorem. But guaranteeing the TVD property is not always feasible. Alternatively, appropriate modifications of the flux/slope limiters are implemented here to enforce a maximum principle for any global/control variable built as first-order homographic function of its components. [less ▲]

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See detailNumerical shear tests for different elasto-plastic laws
de Montleau, P.; Duchene, Laurent ULg; Flores, Paulo et al

in Onate, E.; Owen, D. R. J. (Eds.) Proceedings of the VII International Conference on Computational Plasticity (COMPLAS 2003) (2003)

This paper presents the numerical simulation of a cyclic simple shear test. The blank tested is a high strength steel sheet for which we use three different constitutive plastic laws derived from Teodosiu ... [more ▼]

This paper presents the numerical simulation of a cyclic simple shear test. The blank tested is a high strength steel sheet for which we use three different constitutive plastic laws derived from Teodosiu's model. These laws take into account respectively isotropic, kinematic and mixed isotropic-kinematic hardening. The goal of the paper is to provide a first numerical idea of the stress-strain path in the center of an experimental test sample. [less ▲]

Detailed reference viewed: 34 (7 ULg)
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See detailNumerical simulation and experimental validation of murine fracture healing
Geris, Liesbet ULg; Gerisch, A.; Maes, C. et al

in Proceedings of the fifth national day on biomedical engineering (2005)

Detailed reference viewed: 5 (0 ULg)
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See detailNumerical simulation and experimental validation of murine fracture healing
Geris, Liesbet ULg; Gerisch, A.; Maes, C. et al

in Proceedings of the European Conference on Mathematical and Theoretical Biology (2005)

Detailed reference viewed: 4 (0 ULg)
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See detailNumerical simulation and performance assessment of an absorption solar air-conditioning system coupled with an office building
Thomas, Sébastien ULg; Andre, Philippe ULg

in Building Simulation: An International Journal (2012), 5(3), 243-255

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide a part of the heating needs. Moreover, it can drive absorption chiller in order to satisfy the cooling needs of buildings. The objective of the work is to evaluate accurately the energy consumption of an air-conditioning system including a solar driven absorption chiller. The complete simulation environment includes the absorption chiller itself, the cooling tower, the solar collectors field, heater, storage devices, pumps, heating-cooling distribution, emission system and building. A decrease of primary energy consumption of 22% for heating and cooling is reached when using a solar air-conditioning system instead of classical heating and cooling devices. The modelling of each subsystem is detailed. TRNSYS software modular approach provides the possibility to model and simulate this complete system. [less ▲]

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See detailNumerical simulation and performance assessment of an absorption solar air-conditioning system coupled with an office building
Thomas, Sébastien ULg; Andre, Philippe ULg

Conference (2010, December)

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide a part of the heating needs. Moreover, it can drive absorption chiller in order to satisfy the cooling needs of buildings. The objective of the work is to evaluate accurately the energy consumption of an air conditioning system including a solar driven absorption chiller. The complete simulation environment includes the absorption chiller itself, the cooling tower, the solar collectors field, heater, storage devices, pumps, heating-cooling distribution, emission system and building. The modelling of each subsystem is detailed. TRNSYS software modular approach provides the possibility to model and simulate this complete system. [less ▲]

Detailed reference viewed: 71 (10 ULg)
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See detailThe numerical simulation and physical model test of pipeline under water action
Marchal, Jean ULg; Yucheng, Li; Guozhang, Lai et al

in Proceedings of the Fourth Pacific/Asia Offshore Mechanics Symposium, Pusan, Korea (1996)

Detailed reference viewed: 33 (0 ULg)
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See detailNumerical simulation and Visualization of Material Flow in Friction Stir Welding via Particle Tracing
Dialami, Narges; Chiumenti, Michele; Cervera, Miguel et al

in Idelsohn, Sergio (Ed.) Numerical Simulations of Coupled Problems in Engineering (2014)

This work deals with the numerical simulation and material flow visualization of Friction Stir Welding (FSW) processes. The fourth order Runge- Kutta (RK4) integration method is used for the computation ... [more ▼]

This work deals with the numerical simulation and material flow visualization of Friction Stir Welding (FSW) processes. The fourth order Runge- Kutta (RK4) integration method is used for the computation of particle trajectories. The particle tracing method is used to study the effect of input process parameters and pin shapes on the weld quality. The results show that the proposed method is suitable for the optimization of the FSW process. [less ▲]

Detailed reference viewed: 31 (6 ULg)