https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 05 Jun 2026 22:47:30 GMT 2026-06-05T22:47:30Z http://hdl.handle.net/10985/7625 INVESTIGATIONS IN A VANED DIFFUSER OF SHF IMPELLER DUPONT, Patrick; CAVAZZINI, Giovanna; CHERDIEU, Patrick; BOIS, Gérard; ROUSSETTE, Olivier; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude The paper presents the numerical and experimental analysis of performance and internal flow behaviour in the vaned diffuser of a radial flow pump (Fig. 1) using PIV technique (Fig. 2), pressure probe traverses and numerical simulations. PIV measurements have been performed at different heights inside one diffuser channel passage for a given speed of rotation and various mass flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly, to cover the space between the leading edge of the impeller and the diffuser throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Hub to shroud directional probe traverses (Fig. 3) have also been performed using a 3 holes pressure probe along the diffuser width at different radial locations between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 7.02.011 (at LML), ii-CFX 10.0 (at University of Padova). Fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for different mass flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. Experimental results strongly depend on impeller position during its rotation. Pressure probe results are also depending on unsteady effects and this has to be taken into account for further data reduction analysis. The contours of radial and tangential velocity at mid high (Fig. 4) as well as the time-averaged values of radial and tangential velocity distributions allow leakage to be an important parameter that has to be taken into account in order to make comparisons between numerical and experiments. Henceforth, simulations with fluid leakages will be realized and unsteady probes will be used in order to confirm these previous results. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7625 2013-01-01T00:00:00Z DUPONT, Patrick CAVAZZINI, Giovanna CHERDIEU, Patrick BOIS, Gérard ROUSSETTE, Olivier DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude The paper presents the numerical and experimental analysis of performance and internal flow behaviour in the vaned diffuser of a radial flow pump (Fig. 1) using PIV technique (Fig. 2), pressure probe traverses and numerical simulations. PIV measurements have been performed at different heights inside one diffuser channel passage for a given speed of rotation and various mass flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly, to cover the space between the leading edge of the impeller and the diffuser throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Hub to shroud directional probe traverses (Fig. 3) have also been performed using a 3 holes pressure probe along the diffuser width at different radial locations between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 7.02.011 (at LML), ii-CFX 10.0 (at University of Padova). Fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for different mass flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. Experimental results strongly depend on impeller position during its rotation. Pressure probe results are also depending on unsteady effects and this has to be taken into account for further data reduction analysis. The contours of radial and tangential velocity at mid high (Fig. 4) as well as the time-averaged values of radial and tangential velocity distributions allow leakage to be an important parameter that has to be taken into account in order to make comparisons between numerical and experiments. Henceforth, simulations with fluid leakages will be realized and unsteady probes will be used in order to confirm these previous results. http://hdl.handle.net/10985/6730 Comparaisons between numerical calculations and measurements in the vaned diffusor of SHF impeller DUPONT, Patrick; CHERDIEU, Patrick; BOIS, Gérard; ROUSSETTE, Olivier; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude The paper presents analysis of the performance and the internal flow behaviour in the vaned diffusor of a radial flow pump using PIV technique and pressure probe traverses. PIV measurements have been performed at mid height inside one diffusor channel passage for a given speed of rotation and various mass flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly ,to cover the space between the leading edge and the diffusor throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Probe traverses have been performed using a 3 holes pressure probe from hub to shroud diffusor width at different radial locations in between the two diffusor geometrical throats. The numerical simulations were realized with the commercial codes: i-Star CCM+ 7.02.011, ii-CFX. Frozen rotor and fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for one mass flow rate. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/6730 2012-01-01T00:00:00Z DUPONT, Patrick CHERDIEU, Patrick BOIS, Gérard ROUSSETTE, Olivier DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude The paper presents analysis of the performance and the internal flow behaviour in the vaned diffusor of a radial flow pump using PIV technique and pressure probe traverses. PIV measurements have been performed at mid height inside one diffusor channel passage for a given speed of rotation and various mass flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly ,to cover the space between the leading edge and the diffusor throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Probe traverses have been performed using a 3 holes pressure probe from hub to shroud diffusor width at different radial locations in between the two diffusor geometrical throats. The numerical simulations were realized with the commercial codes: i-Star CCM+ 7.02.011, ii-CFX. Frozen rotor and fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for one mass flow rate. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. http://hdl.handle.net/10985/9699 Comparisons rans and urans numerical results with experiments in a vaned diffuser of a centrifugal pump; Comparaisons de différents modèles numériques à des résultats expérimentaux dans un diffuseur aubé de pompe centrifuge DUPONT, Patrick; CAVAZZINI, Giovanna; PAVESI, Giorgio; CHERDIEU, Patrick; BOIS, Gérard; ROUSSETTE, Olivier; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude The paper presents the analysis of the performance and the internal flow behaviour in the vaned diffuser of a radial flow pump using PIV (particles image velocimetry) technique, pressure probe traverses and numerical simulations. PIV measurements have been performed at different hub to shroud planes inside one diffuser channel passage for a given rotational speed and various flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. Probe traverses have also been performed using a 3 holes pressure probe from hub to shroud diffuser width at different radial locations in between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 8.02.011 (RANS (Reynolds Averaged Navier Stokes) turbulence model, frozen rotor and unsteady calculations), ii-CFX 10.0 (turbulence modelled with DES model (Detached Eddy Simulation) combining RANS with LES (Large Eddy Simulation), unsteady calculations). Comparisons between numerical (fully unsteady calculations) and experimental results are presented and discussed for two flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed.; L’analyse des performances et de l’écoulement interne dans un diffuseur aubé de la pompe centrifuge SHF (testée en air) fait l’objet de ce papier. La particularité de cette pompe est qu’il n’y a pas de volute à l’aval de telle sorte que l’écoulement refoule à l’air libre. Une caractéristique de ce diffuseur est que son débit nominal correspond à 80% du débit nominal de la roue. L’analyse des performances est réalisée grâce à la technique PIV (Vélocimétrie par images de particules), aux sondes de pression trois trous et aux simulations numériques. Les mesures PIV ont été réalisées pour différents plans entre le carter et le moyeu dans un canal du diffuseur, pour une vitesse de rotation de roue fixée, et différents débits. Dans chaque cas, les mesures PIV ont été effectuées pour sept différentes positions angulaires de la roue, deux positions seulement sont ici présentées. Des sondes de pression trois trous ont également été utilisées dans le diffuseur à différentes positions radiales et axiales, en entrée et sortie du diffuseur et dans le canal inter-aubes. Les simulations numériques ont été réalisées à l’aide de deux codes de calcul: i-Star CCM+ 8.02.011 (modélisations RANS en « frozen rotor » et en calculs instationnaires), ii-CFX 10.0 (calculs instationnaires, modélisation de la turbulence par DES combinant un modèle RANS avec la LES ). Les mesures réalisées avec les sondes trois trous et les résultats des simulations numériques donnent des informations sur les évolutions des coefficients de pressions statiques et dynamiques. On a pu constater que les performances globales de la machine dépendaient peu des débits de fuite. D’un point de vue local, seules les vitesses radiales et tangentielles sont ici comparées. Les courbes vr en fonction du rayon, dans le canal inter-aubes du diffuseur, pour deux débits encadrant le débit nominal de la roue, montrent que les résultats expérimentaux sont en bonne correspondance avec la courbe de simulation numérique tenant compte de fuites entre le diffuseur et la roue. L’analyse quantitative des iso valeurs vr et vu donne une idée des structures présentes dans le diffuseur. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9699 2015-01-01T00:00:00Z DUPONT, Patrick CAVAZZINI, Giovanna PAVESI, Giorgio CHERDIEU, Patrick BOIS, Gérard ROUSSETTE, Olivier DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude The paper presents the analysis of the performance and the internal flow behaviour in the vaned diffuser of a radial flow pump using PIV (particles image velocimetry) technique, pressure probe traverses and numerical simulations. PIV measurements have been performed at different hub to shroud planes inside one diffuser channel passage for a given rotational speed and various flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. Probe traverses have also been performed using a 3 holes pressure probe from hub to shroud diffuser width at different radial locations in between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 8.02.011 (RANS (Reynolds Averaged Navier Stokes) turbulence model, frozen rotor and unsteady calculations), ii-CFX 10.0 (turbulence modelled with DES model (Detached Eddy Simulation) combining RANS with LES (Large Eddy Simulation), unsteady calculations). Comparisons between numerical (fully unsteady calculations) and experimental results are presented and discussed for two flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. L’analyse des performances et de l’écoulement interne dans un diffuseur aubé de la pompe centrifuge SHF (testée en air) fait l’objet de ce papier. La particularité de cette pompe est qu’il n’y a pas de volute à l’aval de telle sorte que l’écoulement refoule à l’air libre. Une caractéristique de ce diffuseur est que son débit nominal correspond à 80% du débit nominal de la roue. L’analyse des performances est réalisée grâce à la technique PIV (Vélocimétrie par images de particules), aux sondes de pression trois trous et aux simulations numériques. Les mesures PIV ont été réalisées pour différents plans entre le carter et le moyeu dans un canal du diffuseur, pour une vitesse de rotation de roue fixée, et différents débits. Dans chaque cas, les mesures PIV ont été effectuées pour sept différentes positions angulaires de la roue, deux positions seulement sont ici présentées. Des sondes de pression trois trous ont également été utilisées dans le diffuseur à différentes positions radiales et axiales, en entrée et sortie du diffuseur et dans le canal inter-aubes. Les simulations numériques ont été réalisées à l’aide de deux codes de calcul: i-Star CCM+ 8.02.011 (modélisations RANS en « frozen rotor » et en calculs instationnaires), ii-CFX 10.0 (calculs instationnaires, modélisation de la turbulence par DES combinant un modèle RANS avec la LES ). Les mesures réalisées avec les sondes trois trous et les résultats des simulations numériques donnent des informations sur les évolutions des coefficients de pressions statiques et dynamiques. On a pu constater que les performances globales de la machine dépendaient peu des débits de fuite. D’un point de vue local, seules les vitesses radiales et tangentielles sont ici comparées. Les courbes vr en fonction du rayon, dans le canal inter-aubes du diffuseur, pour deux débits encadrant le débit nominal de la roue, montrent que les résultats expérimentaux sont en bonne correspondance avec la courbe de simulation numérique tenant compte de fuites entre le diffuseur et la roue. L’analyse quantitative des iso valeurs vr et vu donne une idée des structures présentes dans le diffuseur. http://hdl.handle.net/10985/7723 Comparisons Between Numerical Calculations and Measurements in the Vaned Diffusor of SHF Impeller BAYEUL-LAINÉ, Annie-Claude; DUPONT, Patrick; CAVAZZINI, Giovanna; CHERDIEU, Patrick; DAZIN, Antoine; BOIS, GERARD; ROUSSETTE, Olivier The paper presents analysis of the performance and the internal flow behaviour in the vaned diffusor of a radial flow pump using PIV (Particle Image Velocimetry) and pressure probe traverses. PIV measurements have already been performed at mid height inside one diffusor channel passage for a given speed of rotation and various mass flow rates. These results have been already presented in several previous communications. New experiments have been performed using a 3 holes pressure probe traverses from hub to shroud diffusor width at different radial locations between the two diffusor geometrical throats. Numerical simulations are also realized with the commercial codes Star CCM+ 7.02.011 and CFX. Frozen rotor and fully unsteady calculations of the whole pump have been performed. Comparisons between numerical results, previous experimental PIV results and new probe traverses one’s are presented and discussed for one mass flow rate. In this respect, a first attempt to take into account fluid leakages between the rotating and fixed part of the pump has been checked since it may affect the real flow structure inside the diffuser The authors wish to thank Region Nord-Pas de Calais and CNRS for their financial support in the frame of the CISIT program Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7723 2013-01-01T00:00:00Z BAYEUL-LAINÉ, Annie-Claude DUPONT, Patrick CAVAZZINI, Giovanna CHERDIEU, Patrick DAZIN, Antoine BOIS, GERARD ROUSSETTE, Olivier The paper presents analysis of the performance and the internal flow behaviour in the vaned diffusor of a radial flow pump using PIV (Particle Image Velocimetry) and pressure probe traverses. PIV measurements have already been performed at mid height inside one diffusor channel passage for a given speed of rotation and various mass flow rates. These results have been already presented in several previous communications. New experiments have been performed using a 3 holes pressure probe traverses from hub to shroud diffusor width at different radial locations between the two diffusor geometrical throats. Numerical simulations are also realized with the commercial codes Star CCM+ 7.02.011 and CFX. Frozen rotor and fully unsteady calculations of the whole pump have been performed. Comparisons between numerical results, previous experimental PIV results and new probe traverses one’s are presented and discussed for one mass flow rate. In this respect, a first attempt to take into account fluid leakages between the rotating and fixed part of the pump has been checked since it may affect the real flow structure inside the diffuser http://hdl.handle.net/10985/7458 NUMERICAL AND EXPERIMENTAL INVESTIGATIONS IN A VANED DIFFUSER OF SHF IMPELLER: FLUID LEAKAGE EFFECT DUPONT, Patrick; CAVAZZINI, Giovanna; CHERDIEU, Patrick; BOIS, Gérard; ROUSSETTE, Olivier; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude The paper presents the analysis of the performance and the internal flow behaviour in the vaned diffuser of a radial flow pump using PIV technique, pressure probe traverses and numerical simulations. PIV measurements have been performed at different heights inside one diffuser channel passage for a given speed of rotation and various flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly, to cover the space between the leading edge of the impeller and the diffuser throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Probe traverses have also been performed using a 3 holes pressure probe from hub to shroud diffuser width at different radial locations in between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 7.02.011 (at LML), ii-CFX 10.0 (at University of Padova). Fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for two flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7458 2013-01-01T00:00:00Z DUPONT, Patrick CAVAZZINI, Giovanna CHERDIEU, Patrick BOIS, Gérard ROUSSETTE, Olivier DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude The paper presents the analysis of the performance and the internal flow behaviour in the vaned diffuser of a radial flow pump using PIV technique, pressure probe traverses and numerical simulations. PIV measurements have been performed at different heights inside one diffuser channel passage for a given speed of rotation and various flow rates. For each operating condition, PIV measurements have been made for different angular positions of the impeller. For each angular position, instantaneous velocities charts have been obtained on two simultaneous views, which allows, firstly, to cover the space between the leading edge of the impeller and the diffuser throat and secondly, to get a rather good evaluation of phase averaged velocity charts and “fluctuating rates “. Probe traverses have also been performed using a 3 holes pressure probe from hub to shroud diffuser width at different radial locations in between the two diffuser geometrical throats. The numerical simulations were realized with the two commercial codes: i-Star CCM+ 7.02.011 (at LML), ii-CFX 10.0 (at University of Padova). Fully unsteady calculations of the whole pump were performed. Comparisons between numerical and experimental results are presented and discussed for two flow rates. In this respect, the effects of fluid leakage due to the gap between the rotating and fixed part of the pump model are analysed and discussed. http://hdl.handle.net/10985/7601 Data reduction problems using a 3 holes directional pressure probe to investigate mean flow characteristics in the vaneless gap between impeller and diffuser radial pump CHERDIEU, Patrick; DUPONT, Patrick; BOIS, Gérard; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude Among several different measurement techniques that have been already performed and presented in a radial impeller pump model including PIV, a directional pressure probe has been used to obtain mean velocity field and stagnation pressure between impeller outlet and the inlet vaned diffuser sections. These measurements are supposed to get more information not only about global pump head coefficient including vaned diffuser ones but also about impeller performances itself. Pressure probe information is affected by rotor-stator interactions and impeller rotation, and this paper presents a way to explain and correct pressure probe indications in order to achieve a better evaluation of overall impeller mean performances. The use of unsteady RANS calculation results is found to be a useful way to perform better data reduction analysis for this purpose Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7601 2013-01-01T00:00:00Z CHERDIEU, Patrick DUPONT, Patrick BOIS, Gérard DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude Among several different measurement techniques that have been already performed and presented in a radial impeller pump model including PIV, a directional pressure probe has been used to obtain mean velocity field and stagnation pressure between impeller outlet and the inlet vaned diffuser sections. These measurements are supposed to get more information not only about global pump head coefficient including vaned diffuser ones but also about impeller performances itself. Pressure probe information is affected by rotor-stator interactions and impeller rotation, and this paper presents a way to explain and correct pressure probe indications in order to achieve a better evaluation of overall impeller mean performances. The use of unsteady RANS calculation results is found to be a useful way to perform better data reduction analysis for this purpose http://hdl.handle.net/10985/7460 Analysis of Unsteadinesses in a Vaned Diffuser of Centrifugal Machinery. CHERDIEU, Patrick; DAZIN, Antoine; DUPONT, Patrick; BAYEUL-LAINÉ, Annie-Claude; ROUSSETTE, Olivier; BOIS, Gérard The aim of this article is to present experimental results obtained on a fan composed of a radial impeller matched with a vaned diffuser. There is no volute downstream to the diffuser. Consequently the diffuser outlet is at free air. The particularity of this machinery is that the diffuser design flow rate corresponds to 80% of the impeller one. Investigations have been made for five different flow rates. Global performances of the machine are evaluated thanks to pressure measurements and averaged velocities obtain with a three holes probe, at nine angular positions at diffuser inlet and outlet just as five radial positions in a middle section of a blade-to-blade passage. In order to better characterize separations observed in previous experimental and numerical studies unsteady pressure measurement campaigns have been carried out. The transducers are located at five positions on the pressure face and four positions on the suction face on diffuser vanes in a blade-to-blade plane. For each position, three transducers are located at three different heights, from hub to shroud. Unsteadinesses revealed by these measurements just as theirs effects on the diffuser performance are analysed. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7460 2013-01-01T00:00:00Z CHERDIEU, Patrick DAZIN, Antoine DUPONT, Patrick BAYEUL-LAINÉ, Annie-Claude ROUSSETTE, Olivier BOIS, Gérard The aim of this article is to present experimental results obtained on a fan composed of a radial impeller matched with a vaned diffuser. There is no volute downstream to the diffuser. Consequently the diffuser outlet is at free air. The particularity of this machinery is that the diffuser design flow rate corresponds to 80% of the impeller one. Investigations have been made for five different flow rates. Global performances of the machine are evaluated thanks to pressure measurements and averaged velocities obtain with a three holes probe, at nine angular positions at diffuser inlet and outlet just as five radial positions in a middle section of a blade-to-blade passage. In order to better characterize separations observed in previous experimental and numerical studies unsteady pressure measurement campaigns have been carried out. The transducers are located at five positions on the pressure face and four positions on the suction face on diffuser vanes in a blade-to-blade plane. For each position, three transducers are located at three different heights, from hub to shroud. Unsteadinesses revealed by these measurements just as theirs effects on the diffuser performance are analysed.