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Peer Reviewed
See detailExperimental Infection of Specific Pathogen-Free New Zealand White Rabbits with Five Strains of Amyxomatous Myxoma Virus
Marlier, Didier ULg; Cassart, Dominique ULg; Boucraut-Baralon, C. et al

in Journal of Comparative Pathology (1999), 121(4), 369-84

Myxomatosis is a specific disease of the European rabbit (Oryctolagus cuniculus) due to a virus belonging to the genus Leporipoxvirus. Forty-seven years after its deliberate introduction into Europe, the ... [more ▼]

Myxomatosis is a specific disease of the European rabbit (Oryctolagus cuniculus) due to a virus belonging to the genus Leporipoxvirus. Forty-seven years after its deliberate introduction into Europe, the clinical aspects and the epizootiology of myxomatosis have changed. Two forms (nodular and amyxomatous) of the disease have been identified to date. A comparative study was made of the clinical signs, pathogenesis and gross lesions observed in male specific pathogen-free New Zealand White rabbits inoculated with five strains of amyxomatous myxoma virus. All five strains induced the characteristic amyxomatous myxomatosis clinical syndrome with clinical signs that differed only in intensity. The varying clinical intensity, together with the results of virological examination question the virulence of at least three of the five strains. Genomic analysis confirmed that the five strains came from the Lausanne strain introduced in 1952 in France and not from an unnoticed introduction of a Californian strain of myxoma virus. No link was found between the amyxomatous myxoma virus strains and the SG33 vaccine strain. 1999 Harcourt Publishers Ltd. [less ▲]

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See detailExperimental investigation and phenomenological modeling of the quasi-static mechanical behavior of TA6V titanium alloy
Gilles, Gaëtan ULg; Habraken, Anne ULg; Duchene, Laurent ULg

in Key Engineering Materials [=KEM] (2014), 622-623

This paper proposes an experimental and numerical investigation of the quasi-static mechanical behavior of TA6V at room temperature. Different loading conditions ( tension, compression, plane strain ans ... [more ▼]

This paper proposes an experimental and numerical investigation of the quasi-static mechanical behavior of TA6V at room temperature. Different loading conditions ( tension, compression, plane strain ans simple shear) were applied on a 0.6 mm thick sheet in several in plane directions. Based on the experimental results, several identifications are performed to determinate the parameters involved in the CPB06 yield criterion and its extensions. The error/time computation ratio for the different identifications is next analysed to fix the choice of the yield criterion. The latter is finally associated with an isotropic hardening law on the one side and a formulation taking into account the evolution of the yield locus on the other side in order to describe the material. The ability of the proposed formulations to predict the TA6V response is studied int he case of a deep-drawing process. [less ▲]

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See detailExperimental investigation of an ORC system for a micro-solar power plant
Dickes, Rémi ULg; Dumont, Olivier ULg; Declaye, Sébastien ULg et al

Conference (2014)

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed ... [more ▼]

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed, solar energy, and more specifically CSP (Concentrated Solar Power) systems are expected to play a key role to supply centralized loads and off-grid areas in the medium-term. Major performance improvements can be achieved by implementing advanced control strategies accounting for the transient and random nature of the solar heat source. In this context, a lab-scale solar power plant has been designed and is under construction for experimental purposes and dynamic analysis. The test rig includes an Organic Rankine Cycle (ORC) unit, a field of parabolic trough collectors and a thermal energy storage system. This paper presents the results of an experimental campaign conducted on the ORC module alone. This power unit, designed for a 2.8 kW net electrical output, consists of two scroll expanders in series, an air-cooled condenser, a recuperator, a volumetric pump and an oil-heated evaporator. The ORC engine is constructed using standard mass manufactured components from the HVAC industry, this practice reducing considerably the system cost. The overall unit performance and components effectiveness are presented in different operating conditions and relevant empirical correlations are derived to be implemented in a steady state model of the ORC unit. [less ▲]

Detailed reference viewed: 105 (23 ULg)
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See detailExperimental investigation of droplet biosensing by multi-wavelength plasmonic
Desfours, Caroline ULg; Habraken, Serge ULg; Hastanin, Juriy ULg et al

in Proceedings of SPIE Vol. 8234 : Plasmonics in Biology and Medicine IX (2012)

Detailed reference viewed: 46 (16 ULg)
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See detailExperimental investigation of flow and deposit patterns in rectangular shallow reservoirs: preliminary analysis
Dufresne, Matthieu ULg; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Proceedings International Workshop on Environmental Hydraulics: Theoretical, Experimental and Computational Solutions (2009)

Detailed reference viewed: 19 (3 ULg)
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See detailExperimental investigation of flow pattern and sediment deposition in rectangular shallow reservoirs
Dufresne, Matthieu; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in International Journal of Sediment Research (2010), 25(3), 258-270

This work involved the experimental investigation of flow pattern, preferential regions of deposition and trap efficiency as a function of the length of rectangular shallow reservoirs. Four flow patterns ... [more ▼]

This work involved the experimental investigation of flow pattern, preferential regions of deposition and trap efficiency as a function of the length of rectangular shallow reservoirs. Four flow patterns were identified (from longer to shorter reservoirs): an asymmetric flow with two reattachment points, an asymmetric flow with one reattachment point, an unstable flow, and a symmetric flow without any reattachment point. Using dye visualizations, the median value and the temporal variability of the reattachment lengths were precisely measured for the asymmetric flows. For each stable flow, sediment tests with plastic particles were carried out. The regions of deposition on the bed of the reservoir were clearly a function of the flow pattern. The transition from an asymmetric flow pattern to a symmetric flow pattern was responsible for an abrupt decrease of the trap efficiency; a number of regression laws were discussed to take it into account. [less ▲]

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See detailExperimental investigation of meandering jets in shallow reservoirs
Peltier, Yann ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Environmental Fluid Mechanics (2014)

Meandering flows in rectangular shallow reservoirs were experimentally investi- gated. The characteristic frequency, the longitudinal wave length and the mean lateral exten- sion of the meandering jet ... [more ▼]

Meandering flows in rectangular shallow reservoirs were experimentally investi- gated. The characteristic frequency, the longitudinal wave length and the mean lateral exten- sion of the meandering jet were extracted from the first paired modes, obtained by a proper orthogonal decomposition of the surface velocity field measured by large scale PIV. The depth-normalised characteristic lengths and the Strouhal number were then compared to the main dimensionless numbers characterizing the experiments: Froude number, friction num- ber and reservoir shape factor. The normalised wave length and mean lateral extension of the meandering jet are neither correlated with the Froude number nor with the reservoir shape factor; but a clear relationship is found with the friction number. Similarly, the Strouhal num- ber is found proportional to a negative power of the friction number. In contrast, the Froude number and the reservoir shape factor enable to predict the occurrence of a meandering flow pattern: meandering jets occur for Froude number greater than 0.21 and for a shape factor smaller than 6.2. [less ▲]

Detailed reference viewed: 45 (18 ULg)
See detailEXPERIMENTAL INVESTIGATION OF NOx FORMATION MECHANISMS IN A FUEL-OIL BOILER
Tartari, Paula; Ngendakumana, Philippe ULg

Conference (2002, June)

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better ... [more ▼]

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better understanding of the combustion process and thus a correct basis for combustion modeling, focused on NOx formation. In order to attain the objective, axial and radial temperature, NOx and O2 concentration profiles have been measured in the flame for high and low firing rates of a domestic hot water boiler (around 424 and 270 kW respectively). Temperature was measured by means of two B-type thermocouples (diameters 0.5 and 0.35 mm) and NOx and O2 concentrations using a classical gas analyzer. Maximum NOx emissions (167 ppm at 424 kW and 134 ppm at 270 kW) were recorded in high oxygen concentration and low temperature zones of the flame ( ≈ 1000°C), where no thermal-NO can be formed. Flue gas recirculation and NOx destruction process is clearly demonstrated in the flame due to the higher NOx concentrations recorded in the combustion chamber near the burner exit than in the chimney. Near the burner exit NOx, O2 and temperature radial profiles are very unstable. Higher temperature fluctuations were detected with the small thermocouple in the measurements at 270 kW. The contribution of the three types of NOx formation mechanisms was obtained using a simplified model. According to these results, the majority of NOx in this type of flame could be caused by the prompt-NO mechanism, formed in the zone close to the burner exit at the location where secondary combustion air is introduced. [less ▲]

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See detailExperimental investigation of passive/active oxidation behavior of SiC based ceramic thermal protection materials exposed to high enthalpy plasma
Sakraker, Isil ULg; Asma, Cem Ozan

in Journal of the European Ceramic Society (2013), 33(2), 351-359

The passive/active oxidation behavior of a CVD-SiC coated C/C-SiC thermal protection material of the hypersonic SpaceLiner vehicle is investigated experimentally. For the safety of spacecraft and its ... [more ▼]

The passive/active oxidation behavior of a CVD-SiC coated C/C-SiC thermal protection material of the hypersonic SpaceLiner vehicle is investigated experimentally. For the safety of spacecraft and its passengers, it is important to know whether the thermal protection system will experience passive/active oxidation during the vehicle’s entry into Earth’s atmosphere. Active oxidation can promote material loss whereas passive oxidation forms a protective film. The high enthalpy flight conditions of SpaceLiner vehicle are duplicated in VKI Plasmatron, where the samples are exposed to high enthalpy plasma and the surface temperatures increase up to 2800 K at various total pressure (2–20 kPa) conditions. Surface temperature profiles, visual characteristics, mass changes, emissivity, spectrometer and SEM/EDX data are examined to identify the oxidation transition border of the tested material. A temperature jump is observed in all active oxidation regimes. The experimental results are found to be in good agreement with correlations from the literature. [less ▲]

Detailed reference viewed: 63 (6 ULg)
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See detailExperimental investigation of targeted energy transfers in strongly and nonlinearly coupled oscillators
McFarland, D. Michael; Kerschen, Gaëtan ULg; Kowtko, Jeffrey J. et al

in Journal of the Acoustical Society of America (2005), 118(2), 791-799

Our focus in this study is on experimental investigation of the transient dynamics of an impulsively loaded linear oscillator coupled to a lightweight nonlinear energy sink. It is shown that this ... [more ▼]

Our focus in this study is on experimental investigation of the transient dynamics of an impulsively loaded linear oscillator coupled to a lightweight nonlinear energy sink. It is shown that this seemingly simple system exhibits complicated dynamics, including nonlinear beating phenomena and resonance captures. It is also demonstrated that, by facilitating targeted energy transfers to the nonlinear energy sink, a significant portion of the total input energy can be absorbed and dissipated in this oscillator. (C) 2005 Acoustical Society of America. [less ▲]

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See detailExperimental investigation of the aeroacoustic coupling between the non-planar modes of a resonator and the misaligned jet-slot oscillator
Glesser, Martin; Valeau, Vincent; Billon, Alexis ULg et al

in Acta Acustica United with Acustica (2009), 95(3), 512-518

The jet-slot oscillator is a source of aeroacoustic self-sustained tones resulting from the impingement of the vortical structures of a plane jet onto a slotted plate. The coupling of this type of ... [more ▼]

The jet-slot oscillator is a source of aeroacoustic self-sustained tones resulting from the impingement of the vortical structures of a plane jet onto a slotted plate. The coupling of this type of aeroacoustic source with high-order acoustic resonances of the flow-supply duct is experimentally studied, in the particular case where the jet-exit and the obstacle are misaligned in the spanwise direction. An experimental setup based on microphones and hot-wire probes is used to investigate this coupling. It is shown that: (i) the misaligned jet-slot oscillator can be coupled to non-planar (transverse) modes of the flow-supply duct, (ii) the vortex tubes spanwise morphology is governed by the phase pattern of the excited modes, and (iii) the impingement of the vortices on the inclined obstacle tends to occur in phase in the spanwise direction, in order to enhance the coherence of the interaction along the slot. An investigation of the excited modes as a function of the plate inclination angle and of the streamwise slot position was then conducted. For small inclination angles, the coupling involves a planar mode or a combination of planar and transverse modes. For higher misalignment angles the coupling involves transverse modes or “opposite-transverse” modes, generating vortices with an inclination angle opposite to the plate inclination angle. The influence of the coupling nature on tone production (emission frequency and SPL) was thus evaluated. [less ▲]

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See detailExperimental Investigation of the Aerodynamics and Aeroelasticity of Flapping, Plunging and Pitching Wings
Norizham, Abdul Razak ULg

Doctoral thesis (2012)

This thesis concerns the experimental analysis of the aerodynamics and aeroelasticity of oscillating wings. It is divided into two sections, an inves- tigation of wings undergoing imposed root flapping ... [more ▼]

This thesis concerns the experimental analysis of the aerodynamics and aeroelasticity of oscillating wings. It is divided into two sections, an inves- tigation of wings undergoing imposed root flapping and pitching motion, such as seen in avian flight and an experimental investigation of the self- excited stall flutter oscillations of a wing undergoing plunging and pitching motion. The objective of the flapping wing investigation is to improve the under- standing of the unsteady aerodynamics of flapping flight. The work con- sists of designing and building a flapping and pitching bird-like mechanical model and testing it in a low speed wind tunnel. The model’s size is sim- ilar to that of a goose. The wind tunnel tests involved the measurement of forces, power, kinematics and local flow velocities using Particle Im- age Velocimetry (PIV). The mechanical model was tested at four different frequencies and three airspeeds. In addition, three different wing profiles were tested. The kinematic modes included pure flapping and combined flapping and pitching. It was shown that pure flapping and pitch-lagging combined motion can lead to interesting aerodynamic phenomena, such as flow separation and dynamic stall. Dynamic stall can cause significant increases in instantaneous lift production, although it also generates a lot of drag. On the contrary, pitch leading combined motion can generate a net propulsive force over the entire cycle. In the stall flutter study, a 6 degree of freedom NACA 0018 wing was sus- pended by springs in the wind tunnel. The wing was then exposed to an airflow at a number of airspeeds and wind-off angles of attack. The wing was instrumented with pressure sensors and accelerometers. In addition, PIV flow measurements were carried out on the wing’s upper surface. The work demonstrates that stall flutter is the result of a combination of dy- namic stall with the elastic properties of the system. The dynamic stall mechanism was studied using the PIV measurements and was found to be different to the classical stall mechanisms that are reported in the litera- ture. The sensitivity of the stall flutter phenomenon to parameters such as airspeed and wind-off angle of attack is demonstrated by means of a two-parameter bifurcation diagram. [less ▲]

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See detailExperimental investigation of the effect of flip bucket splitters on plunge pool geometry
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Wasserwirtschaft (2010), 4

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy ... [more ▼]

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy dissipation and the plunge pool geometry of varied repartitions of splitters along the flip bucket width. In particular, it is shown that some configurations can create more erosion than a continuous channel without flip bucket. [less ▲]

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See detailExperimental investigation of the effect of flip bucket splitters on plunge pool geometry
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in RWTH - IWW (Ed.) Mitteilungen - 15. Deutsches Talsperrensymposium - Talsperren im Wandel (2010)

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy ... [more ▼]

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy dissipation and the plunge pool geometry of varied repartitions of splitters along the flip bucket width. In particular, it is shown that some configurations can create more erosion than a continuous channel without flip bucket. [less ▲]

Detailed reference viewed: 33 (5 ULg)
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See detailAn experimental investigation of the subsonic stall flutter
Li, Jing; Andrinopoulos, Nikolaos; Dimitriadis, Grigorios ULg

in Proceedings of the 2006 International Conference on Noise and Vibration Engineering (2006, September)

This paper reports on experimental investigations of the subsonic stall flutter of a wing in a wind tunnel. Stall flutter (also know as Dynamic Stall) is a LCO phenomenon occurring when all or part of the ... [more ▼]

This paper reports on experimental investigations of the subsonic stall flutter of a wing in a wind tunnel. Stall flutter (also know as Dynamic Stall) is a LCO phenomenon occurring when all or part of the flow over a wing separates and re-attaches at least once during a full oscillation period. In order to investigate the aeroelastic effects of the nonlinearity introduced by the boundary layer growth and flow separation and the ensuing stall-induced LCO, a wind tunnel model of a wing undergoing stall flutter is designed, built and tested. The model is a rectangular wing with constant cross-section free to move in the pitch and plunge directions, restrained by torsional and linear springs respectively. The motion of the wing is measured using laser displacement probes. Two types of stall flutter are observed and measured: 1. Non-symmetric stall flutter, where the flow separates over one side of the wing only, and 2. Symmetric stall flutter, where the flow separates over both sides of the wing (deep stall). The bifurcation behaviour of the wing is very complex and both types of LCO can be observed during a single response history. [less ▲]

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See detailExperimental investigation on a decentralized air handling terminal: procedure of aeraulic and thermal performance determination of the entire unit under several operating conditions
Gendebien, Samuel ULg; Prieels, Luc; Lemort, Vincent ULg

in Proceedings of the 6th European Thermal Sciences Conference (2012, September)

A new local ventilation device is actually developed in such a way to procure ventilation “on demand” in each room, with a maximal effectiveness. It consists in a wall or window frame mounted plane ... [more ▼]

A new local ventilation device is actually developed in such a way to procure ventilation “on demand” in each room, with a maximal effectiveness. It consists in a wall or window frame mounted plane-parallel box, containing two (injection and extraction) fans, an electronic control, and a heat recovery exchanger. The present paper describes the experimental investigations carried out on some single components and on the entire unit in order to characterize the aeraulic and thermal performance of the device. [less ▲]

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See detailExperimental investigation on a hermetic scroll expander
Lemort, Vincent ULg; Quoilin, Sylvain ULg; Pire, Christophe

in Proceedings of the 7th International IIR Conference on Compressors (2009, September)

This paper presents the results of an experimental study carried out on a prototype of hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is R245fa. This system was ... [more ▼]

This paper presents the results of an experimental study carried out on a prototype of hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is R245fa. 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 used for heat pump applications and characterized by a nominal power input of 2.5 kW. 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. Using the experimental data, parameters of a simulation model of the expander are identified. The model is finally used to analyze the measured performance of the expander. [less ▲]

Detailed reference viewed: 404 (37 ULg)