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See detailExperimental assessment of the effect of the real flame emissivity for steel elements engulfed into fire
Tondini, Nicola; Vassart, Olivier; Franssen, Jean-Marc ULg

in Babrauska, Vytenis; Grayson, Stephen; Hirschler, Marcelo (Eds.) et al Proceedings of the Fire and Materials 2013 Conference (2013)

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were ... [more ▼]

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were engulfed into pool fires of two different diameters. Two fuels were used and for both fuels tests without column (used as comparison with existing localised fire models) and with column were performed. The temperature of the column and of the flames were measured at different heights. The width of the flame was also measured and used to calculate the emissivity of the flame the value of which was employed in numerical simulations in order to predict the evolution of the temperature of the steel column. Comparison with numerical analyses where the recommended values of the Eurocode were used is also shown. [less ▲]

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See detailExperimental Assessment of the Influence of Interface Geometries on Structural Dynamic Response
Dossogne, Tilàn ULg; Jerome, Trevor; Lancereau, Damien et al

in Proceedings of the International Modal Analysis Conference (IMAC) XXXV (2017, January)

Jointed interfaces are sources of the greatest amount of uncertainty in the dynamics of a structural assembly. In practice, jointed connections introduce nonlinearity into a system, which is often ... [more ▼]

Jointed interfaces are sources of the greatest amount of uncertainty in the dynamics of a structural assembly. In practice, jointed connections introduce nonlinearity into a system, which is often manifested as a softening response in frequency response, exhibiting amplitude dependent damping and stiffness. Additionally, standard joints are highly susceptible to unrepeatability and variability that make meaningful prediction of the performance of a system prohibitively difficult. This high degree of uncertainty in joint structure predictions is partly due to the physical design of the interface. This paper experimentally assesses the influence of the interface geometry on both the nonlinear and uncertain aspects of jointed connections. The considered structure is the Brake-Reuß beam, which possesses a lap joint with three bolted connections, and can exhibit several different interface configurations. Five configurations with different contact areas are tested, identified, and compared, namely joints with complete contact in the interface, contact only under the pressure cones, contact under an area twice that of the pressure cones, contact only away from the pressure cones and Hertzian contact. The contact only under the pressure cone and Hertzian contact are found to behave linearly in the range of excitation used in this work. The contact area twice that of the pressure cone behaves between the complete contact and contact only under the pressure cone cases. [less ▲]

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See detailExperimental Assessment of The Influence of Interface Geometries on Structural Response
Dossogne, Tilàn ULg; Jerome, Trevor; Lancereau, Damien et al

Poster (2016, September)

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See detailExperimental astrochemistry: from ground-based to space-borne laboratories (Foreword)
De Becker, Michaël ULg; Cottin, Hervé; Fleury-Frenette, Karl ULg et al

in Bulletin de la Société Royale des Sciences de Liège (2015, January), 84(4-6),

The investigation of the origin and evolution of molecules in space environments, either in interstellar or interplanetary conditions, constitutes a topic of high importance in modern space sciences. The ... [more ▼]

The investigation of the origin and evolution of molecules in space environments, either in interstellar or interplanetary conditions, constitutes a topic of high importance in modern space sciences. The presence of diversified and complex molecules motivates astrochemists to explore their formation mechanisms along with the physical conditions ruling these physico-chemical processes. Beside theoretical approaches aiming at simulating these processes, experimental techniques are nowadays frequently applied. Both laboratory and space experiment projects allow to reproduce to some extent the adequate conditions to understand some of these processes. The most recent results based on these techniques, and the prospects for future investigations, including the use of space platforms, were the scientific motivation of this workshop. These proceedings summarize a part of the content of this workshop, including abundant references to the relevant bibliography. [less ▲]

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See detailExperimental campaign and modeling of a low capacity waste heat recovery system based on a single screw expander
Desideri, Adriano ULg; Van Den Broek, Martijn; Gusev, Sergei et al

in 22nd International Compressor Engineering Conference at Purdue, July 14-17, 2014 (2014)

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See detailEXPERIMENTAL CHALLENGES TO THE STANDARD MODEL: A REEVALUATION
Cudell, Jean-René ULg

Doctoral thesis (1987)

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See detailExperimental characterisation and modelling of homogeneous solid suspension in an industrial stirred tank
Calvo, Sébastien ULg; Delafosse, Angélique ULg; Collignon, Marie-Laure ULg et al

in Advances in Mechanical Engineering (2013), Volume 2013

In this work, we study the conditions needed to reach homogeneous distribution of aluminium salts particles in water inside a torispherical bottom shaped stirred tank of 70 L equipped with a Pfaudler RCI ... [more ▼]

In this work, we study the conditions needed to reach homogeneous distribution of aluminium salts particles in water inside a torispherical bottom shaped stirred tank of 70 L equipped with a Pfaudler RCI type impeller and three equispaced vertical baffles. The aim of the present study is to develop a CFD model describing the quality of particle distribution in industrial scale tanks. This model, validated with experimental data, is used afterwards to develop scale-up and scale-down correlations to predict the minimum impeller speed needed to reach homogeneous solid distribution Nhs.The commercial CFD software Fluent 14 is used to model the fluid flow and the solid particle distribution in the tank. Sliding Mesh approach is used to take the impeller motion into account. Assuming that the discrete solid phase has no influence on the continuous liquid phase behaviour, the fluid flow dynamics is simulated independently using the well-known k-ε turbulence model. The liquid-solid mixture behaviour is then described by implementing the Eulerian Mixture model. Computed liquid velocity fields are validated by comparison with PIV measurements. ComputedNhs were found to be in good agreement with experimental measurements. Results fromdifferent scales allowed correlating Nhs values to the volumetric power consumption. [less ▲]

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See detailExperimental Characterisation of Damage Occuring during Single Point Incremental Forming of a Ferritic Steel
Mertens, Anne ULg; Guzmán Inostroza, Carlos Felipe ULg; Habraken, Anne ULg et al

Poster (2012, September)

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid ... [more ▼]

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid prototyping and/or small series production [1]. However, inaccuracies in the shape of the processed part and material failure constitute important limiting factors for applications. In the present research, a numerical approach, based on the damage model proposed by Gurson [2], has been chosen to analyse and optimise the process, predict the material rupture and the process limit. From experimental observations of plastic deformation and ductile fracture, damage is related to the nucleation, growth and coalescence of microvoids [3]. Gurson’s model uses the volume fraction of these voids as a main variable. Hence the determination of this value is a key factor for a correct identification and validation of the model. More particularly, the present work focuses on two different methods used to experimentally characterise damage occurring during single point incremental forming of a ferritic steel. Void measurements carried out by optical microscopy combined with image analysis have been compared with porosity values obtained from density measurements based on the Archimedes’ principle [4], so as to assess the feasibility of using this method for a quick characterisation of the damage. [less ▲]

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See detailExperimental characterization and constitutive modeling of TA6V mechanical behavior in plane strain state at room temperature
Gilles, Gaëtan ULg; Tuninetti Vásquez, Victor ULg; Ben Bettaieb, Mohamed ULg et al

in AIP Conference Proceedings (2011), 1383

This paper presents an experimental and theoretical study of the quasi-static behavior of TA6V titanium alloy in plane strain state. In order to quantify the anisotropy of the material, tests were carried ... [more ▼]

This paper presents an experimental and theoretical study of the quasi-static behavior of TA6V titanium alloy in plane strain state. In order to quantify the anisotropy of the material, tests were carried out at room temperature on specimens cut out from a sheet along three loading directions. The initial yield locus is described by the phenomenological CPB06ex3 criterion and Voce’s type isotropic hardening is used. Finite element simulations are performed and compared with the experiments. [less ▲]

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See detailExperimental characterization and elasto-plastic modeling of the quasi-static mechanical response of TA-6 V at room temperature
Gilles, Gaëtan ULg; Hammami, Walid ULg; Libertiaux, Vincent ULg et al

in International Journal of Solids & Structures (2011), 48(9), 12771289

The paper presents an experimental study of the quasi-static deformation behavior of a TA-6V in sheet form. To quantify the plastic anisotropy and the tension-compression asymmetry of this material at ... [more ▼]

The paper presents an experimental study of the quasi-static deformation behavior of a TA-6V in sheet form. To quantify the plastic anisotropy and the tension-compression asymmetry of this material at room temperature, monotonic tensile and compressive tests were carried out on specimens cut out along several orientations in the plane of the sheet. It was observed that although the tensile flow stress anisotropy is very mild, the Lankford coefficients’ anisotropy is very pronounced. To describe the observed mechanical response an elastic/plastic approach was used. Yielding was described using a family of yield criteria that account for strength differential effects and allow an improved description of the anisotropy and its evolution through multiple linear transformations. Comparisons between uniaxial monotonic data and FE simulations using the model show a very good agreement. [less ▲]

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See detailExperimental characterization of a hermetic scroll expander for use in a micro-scale Rankine cycle
Lemort, Vincent ULg; Declaye, Sébastien ULg; Quoilin, Sylvain ULg

in Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy (2011)

This paper presents the results of an experimental study carried out on a prototype of a hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is HFC-245fa. This system was ... [more ▼]

This paper presents the results of an experimental study carried out on a prototype of a hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is HFC-245fa. This system was designed to test only the performance of the expander. It is mainly made up of a scroll compressor, a scroll expander, a heat exchanger and a by-pass valve. The latter is used to adjust the pressure ratio imposed to the expander. The expander is originally a compressor designed for heat pump applications and characterized by a nominal power input of 2.5 kWe. Performance of the expander is evaluated in terms of isentropic effectiveness and filling factor as function of the main operating conditions. The study also investigates the impact of oil mass fraction on the expander performance. Maximum overall isentropic effectiveness of 71.03% is measured, which is partly explained by the good volumetric performance of the machine. Using the experimental data, parameters of a semi-empirical simulation model of the expander are identified. This model is used to analyze the measured performance of the expander. Finally, a polynomial empirical model of the expander is proposed for fast and robust simulations of ORC systems. [less ▲]

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See detailExperimental characterization of hafting traces and their recognition in archaeological assemblages
Rots, Veerle ULg; Vermeersch, Pierre M.

in Walker, E. A.; Wenban-Smith, F.; Healy, F. (Eds.) Lithics in Action. Papers from the Conference Lithic Studies in the Year 2000 (2004)

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See detailExperimental Comparative Study on Lithium Chloride and Calcium Chloride Desiccants
Bouzenada, Saliha ULg; Kaabi, A. N.; Fraikin, Laurent ULg et al

in Procedia Computer Science (2016), 83(718-725),

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See detailExperimental comparison of cavity sealing ability of five dental adhesive systems after thermocycling
Cao, L.; Geerts, Sabine ULg; Gueders, Audrey ULg et al

in Journal of Adhesive Dentistry (2003), 5(2, Summer), 139-144

Purpose: To evaluate the cavity sealing obtained after thermocycling with five adhesive systems in which one all-in-one adhesive was compared to three one-bottle adhesives, and to observe the effect of a ... [more ▼]

Purpose: To evaluate the cavity sealing obtained after thermocycling with five adhesive systems in which one all-in-one adhesive was compared to three one-bottle adhesives, and to observe the effect of a low-charged resin layer added to a one-bottle adhesive. Materials and Methods: Twenty-five recently extracted teeth were randomly allocated to five experimental adhesive systems (n = 5 each): Optibond Solo (OS), Scotchbond 1 (SB1), PQ 1, Prompt-L-Pop (PLP), SB1+Revolution (R). On each tooth, two rectangular cavities at the cementoenamel junction were filled with a microhybrid composite (Z100) and the tested adhesives. Teeth were thermocycled and stained with AgNO3 + vitamin C. Leakage was evaluated on a 6-point (0-5) severity scale and the highest score was selected for each restoration. Results were treated by ordinal logistic regression and considered to be significant at p < 0.05. Results: No significant difference was found between leakage values for enamel and dentin interfaces. Leakage scores never exceeded 2 for OS, SB1 and SB1+R, while they reached a maximum of 5 in 20% of PLP cases. OS was significantly better than the other adhesive systems, which were statistically equivalent. The addition of a flowable composite layer on SB1 did not yield a significant difference, but tended to give better results mainly at the dentin interface. Conclusion: The all-in-one adhesive PLP because of quite variable results, seems less reliable than the one-bottle adhesives, of which OS provides significantly the best results. Addition of a flowable composite on SB1 appears to yield slightly better results. [less ▲]

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See detailExperimental comparison of organic fluids for low temperature ORC (organic Rankine cycle) systems for waste heat recovery applications
Desideri, Adriano ULg; Gusev, Sergei; Van den Broek, Martijn et al

in Energy (2016), 97

This contribution experimentally evaluates and compares the performance of an ORC (organic Rankine cycle) system for stationary bottoming WHR (waste heat recovery) application operating with two different ... [more ▼]

This contribution experimentally evaluates and compares the performance of an ORC (organic Rankine cycle) system for stationary bottoming WHR (waste heat recovery) application operating with two different working fluids, SES36 and R245fa. The test rig is a regenerative cycle equipped with a single screw expander modified from a standard compressor characterized by a nominal shaft power of 11 kW. A total of 36 and 43 steady-state points are collected for SES36 and R245fa respectively, over a wide range of operating conditions by changing the expander rotational speed, the pump frequency and the cooling condenser flow rate. The performances of the ORC components are individually evaluated. A maximum expander isentropic efficiency of 60% is reached using SES36 at 3000 rpm, and a value of 52% is reached with R245fa at 3000 rpm. However, for a given pressure ratio the expander output power is higher with R245fa than with SES36. The overall performance of the ORC unit are investigated in terms of first and second law efficiencies and net output power for the two fluids. The results experimentally demonstrate the correlation between the working fluid critical temperature and the ORC unit working characteristics for low temperature waste heat recovery applications. Open experimental data are provided for both fluids. [less ▲]

Detailed reference viewed: 48 (11 ULg)