https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sat, 18 Apr 2026 22:13:13 GMT 2026-04-18T22:13:13Z http://hdl.handle.net/10985/6724 Numerical study of cavitating flow inside a flush valve DUTHEIL, Daniel; CAIGNAERT, Guy; SIMONET, Sophie; BAYEUL-LAINÉ, Annie-Claude In water supply installations, noise pollution often occurs. As a basic component of a system, a flush valve may frequently be a source of noise and vibration generated by cavitation or high turbulence levels. During valve closing or valve opening, cavitation can be a problem. In order to decrease the noise and to improve the design inside a flush valve, some experimental and numerical analyses were carried out in our laboratories. These analyses led to some improvements in the design of the valves. Cavitation occurrence was more specifically addressed, using numerical simulation, and this is the main aim of the present paper. Particularly, the use of a simplified numerical test without cavitation model is compared with one using a cavitation model. In order to define potential cavitation risks in some parts of the valve, it has been found that a simplified approach provides an accurate overview. Computational Fluid Dynamics (CFD) simulations of cavitating flow of water through an industrial flush valve were performed using the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. The flow was assumed turbulent, incompressible and steady. Two commercial CFD codes (Fluent 6.3 and Star CCM+ 3.04.009) were used to analyse the effects of inlet pressure as well as mesh size and mesh type on cavitation intensity in the flush valve. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10985/6724 2011-01-01T00:00:00Z DUTHEIL, Daniel CAIGNAERT, Guy SIMONET, Sophie BAYEUL-LAINÉ, Annie-Claude In water supply installations, noise pollution often occurs. As a basic component of a system, a flush valve may frequently be a source of noise and vibration generated by cavitation or high turbulence levels. During valve closing or valve opening, cavitation can be a problem. In order to decrease the noise and to improve the design inside a flush valve, some experimental and numerical analyses were carried out in our laboratories. These analyses led to some improvements in the design of the valves. Cavitation occurrence was more specifically addressed, using numerical simulation, and this is the main aim of the present paper. Particularly, the use of a simplified numerical test without cavitation model is compared with one using a cavitation model. In order to define potential cavitation risks in some parts of the valve, it has been found that a simplified approach provides an accurate overview. Computational Fluid Dynamics (CFD) simulations of cavitating flow of water through an industrial flush valve were performed using the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. The flow was assumed turbulent, incompressible and steady. Two commercial CFD codes (Fluent 6.3 and Star CCM+ 3.04.009) were used to analyse the effects of inlet pressure as well as mesh size and mesh type on cavitation intensity in the flush valve. http://hdl.handle.net/10985/7623 UNSTEADY VELOCITY PIV MEASUREMENTS AND 3D NUMERICAL CALCULATION COMPATISONS INSIDE THE IMPELLER OF A RADIAL PUMP MODEL CAVAZZINI, Giovanna; DUPONT, Patrick; PAVESI, Giorgio; BOIS, Gérard; DAZIN, Antoine; BAYEUL-LAINÉ, Annie-Claude PIV measurements were performed at mid hub section inside the impeller of a vaned diffuser pump model working with air. Several previous papers have already presented part of impeller flow characteristics mainly for vaneless diffuser and near nominal mass flow rate. This paper concerns the pump configuration where the diffuser blades interacted with the impeller flow. Each PIV measuring plane was related to one particular impeller blade to blade channel and analyzed according to different relative positions of the vaned diffuser. A fully unsteady calculation of the whole pump has been performed and comparisons between numerical and experimental results are presented and discussed for four different mass flow rates. The present analysis is restricted to the outlet section of the impeller blade to blade passage for one particular impeller blade position relative to the diffuser. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/7623 2013-01-01T00:00:00Z CAVAZZINI, Giovanna DUPONT, Patrick PAVESI, Giorgio BOIS, Gérard DAZIN, Antoine BAYEUL-LAINÉ, Annie-Claude PIV measurements were performed at mid hub section inside the impeller of a vaned diffuser pump model working with air. Several previous papers have already presented part of impeller flow characteristics mainly for vaneless diffuser and near nominal mass flow rate. This paper concerns the pump configuration where the diffuser blades interacted with the impeller flow. Each PIV measuring plane was related to one particular impeller blade to blade channel and analyzed according to different relative positions of the vaned diffuser. A fully unsteady calculation of the whole pump has been performed and comparisons between numerical and experimental results are presented and discussed for four different mass flow rates. The present analysis is restricted to the outlet section of the impeller blade to blade passage for one particular impeller blade position relative to the diffuser. 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/10985/6757 Numerical study of the influence of Geometrical Parameters on flow in water Pump-Sump ISSA, Abir; BOIS, Gérard; BAYEUL-LAINÉ, Annie-Claude Water for irrigation, domestic and industrial supply as well for some power generation is normally drawn directly from rivers or from reservoir through sumps. The flow at the pump section sump may have large effects on the pump performances and the operating conditions. The flow patterns in the sump are mainly determined by the shape and scale of the sump. However, it’s not always possible to design a sump pump to provide uniform and stable flow to pumps, due to site constraints. For example in some cases air entraining (surface and subsurface vortex) occurs. These vortices may reduce pump performances and lead to increase plant operating costs. It becomes essential to investigate the pump sump to avoid these non uniformities inlet flow problems. Two approaches (experimental and numerical) are generally followed for such investigation. The numerical approach usually used solves the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. In the validation of this numerical model, emphasis was placed on the prediction of the number, the location, the size and the strength of the various types of vortices. A previous study done by the same hauteur of this one [1], has shown the influence on a single type of mesh with different cell numbers, different intake pipe depths and different water levels, for two turbulence models closure. The present paper mainly focuses, first, on the effect of pump intake location in the sump and secondly on the effect of several inlet velocity gradients at inlet sump section. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10985/6757 2009-01-01T00:00:00Z ISSA, Abir BOIS, Gérard BAYEUL-LAINÉ, Annie-Claude Water for irrigation, domestic and industrial supply as well for some power generation is normally drawn directly from rivers or from reservoir through sumps. The flow at the pump section sump may have large effects on the pump performances and the operating conditions. The flow patterns in the sump are mainly determined by the shape and scale of the sump. However, it’s not always possible to design a sump pump to provide uniform and stable flow to pumps, due to site constraints. For example in some cases air entraining (surface and subsurface vortex) occurs. These vortices may reduce pump performances and lead to increase plant operating costs. It becomes essential to investigate the pump sump to avoid these non uniformities inlet flow problems. Two approaches (experimental and numerical) are generally followed for such investigation. The numerical approach usually used solves the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. In the validation of this numerical model, emphasis was placed on the prediction of the number, the location, the size and the strength of the various types of vortices. A previous study done by the same hauteur of this one [1], has shown the influence on a single type of mesh with different cell numbers, different intake pipe depths and different water levels, for two turbulence models closure. The present paper mainly focuses, first, on the effect of pump intake location in the sump and secondly on the effect of several inlet velocity gradients at inlet sump section. http://hdl.handle.net/10985/6726 Numerical simulation in vertical wind axis turbine with pitch controlled blades DOCKTER, Aurore; BOIS, Gérard; SIMONET, Sophie; BAYEUL-LAINÉ, Annie-Claude Wind energy is more and more used as a renewable energy source character. The present wind turbine is a small one which allows to be used on roofs or in gardens to light small areas like publicity boards, parking, roads or for water pumping, heating... The present turbine has a vertical axis. Each turbine blade combines a rotating movement around its own axis and around the main rotor axis. Due to this combination of movements, flow around this turbine is highly unsteady and needs to be modeled by unsteady calculation. One of the main problems of such geometry is to simulate the two combined movements. The present work is an extended study of one’s made in 2009. In the previous study, some results like contours of pressure and velocity fields were presented for elliptic blades for one specific constant rotational speed and benefits of combined rotating blades was shown. The present paper points up the influence of two different blades geometries for different rotational speeds, different blade stagger angles and different Reynolds numbers related to a wider range of wind speeds. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/6726 2012-01-01T00:00:00Z DOCKTER, Aurore BOIS, Gérard SIMONET, Sophie BAYEUL-LAINÉ, Annie-Claude Wind energy is more and more used as a renewable energy source character. The present wind turbine is a small one which allows to be used on roofs or in gardens to light small areas like publicity boards, parking, roads or for water pumping, heating... The present turbine has a vertical axis. Each turbine blade combines a rotating movement around its own axis and around the main rotor axis. Due to this combination of movements, flow around this turbine is highly unsteady and needs to be modeled by unsteady calculation. One of the main problems of such geometry is to simulate the two combined movements. The present work is an extended study of one’s made in 2009. In the previous study, some results like contours of pressure and velocity fields were presented for elliptic blades for one specific constant rotational speed and benefits of combined rotating blades was shown. The present paper points up the influence of two different blades geometries for different rotational speeds, different blade stagger angles and different Reynolds numbers related to a wider range of wind speeds. http://hdl.handle.net/10985/6731 Spectral analysis of unsteady flow simulation in a small VAWT BOIS, Gérard; SIMONET, Sophie; BAYEUL-LAINÉ, Annie-Claude The vertical axis wind turbine studied in this paper combine two rotations: one rotating movement of each blade around its own axis and one rotating movement around turbine’s axis. The aim of this paper is to analyse the effect of this two combine movements on fields of pressure and on global forces on each blade with time. Preliminary calculations showed, for some initial blade stagger angles (angle between blade 1 and x axis), that flow is highly unsteady and sometimes hardly periodic. The main goal here is to present spectral analysis of unsteady results like temporal pressure on specific points in the domain and temporal forces on blades and to show the influence of the two combine movements for two different blade stagger angles for elliptic blades. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/6731 2012-01-01T00:00:00Z BOIS, Gérard SIMONET, Sophie BAYEUL-LAINÉ, Annie-Claude The vertical axis wind turbine studied in this paper combine two rotations: one rotating movement of each blade around its own axis and one rotating movement around turbine’s axis. The aim of this paper is to analyse the effect of this two combine movements on fields of pressure and on global forces on each blade with time. Preliminary calculations showed, for some initial blade stagger angles (angle between blade 1 and x axis), that flow is highly unsteady and sometimes hardly periodic. The main goal here is to present spectral analysis of unsteady results like temporal pressure on specific points in the domain and temporal forces on blades and to show the influence of the two combine movements for two different blade stagger angles for elliptic blades. 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/10985/6725 Etude numérique instationnaire d'une micro-éolienne à axe vertical BAYEUL-LAINÉ, Annie-Claude; BOIS, Gérard; SIMONET, Sophie Bien que les éoliennes soient une forme très ancienne d’exploitation du vent, ces dernières quarante dernières années ont vu leur évolution et un développement important de leur conception dans le cadre du développement durable. Le présent article propose de présenter le résultat d’une collaboration entre le Laboratoire de Mécanique de Lille et une entreprise en cours de développement Windisplay. Cette entreprise est à l’origine de la création d’une éolienne, support d’affichage publicitaire original. L’intérêt de ce type de support est de fournir un éclairage d’origine éolienne au support publicitaire. L’originalité de cette turbine est la rotation de chaque pale autour de son propre axe qui permet une surface d’affichage deux fois plus grande, mais qui améliore également les performances d’une telle éolienne. De par cette combinaison de mouvements, l’écoulement autour de cette éolienne est fortement instationnaire et nécessite une modélisation adaptée, en particulier pour tenir compte des positions initiales des pales. Le but est de présenter cette modélisation et de donner un certain nombre de résultats tels que des cartes instantanées de vecteurs vitesse ou des contours de pression, mais aussi des résultats plus globaux tels que des couples ou des coefficients de performance. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/6725 2010-01-01T00:00:00Z BAYEUL-LAINÉ, Annie-Claude BOIS, Gérard SIMONET, Sophie Bien que les éoliennes soient une forme très ancienne d’exploitation du vent, ces dernières quarante dernières années ont vu leur évolution et un développement important de leur conception dans le cadre du développement durable. Le présent article propose de présenter le résultat d’une collaboration entre le Laboratoire de Mécanique de Lille et une entreprise en cours de développement Windisplay. Cette entreprise est à l’origine de la création d’une éolienne, support d’affichage publicitaire original. L’intérêt de ce type de support est de fournir un éclairage d’origine éolienne au support publicitaire. L’originalité de cette turbine est la rotation de chaque pale autour de son propre axe qui permet une surface d’affichage deux fois plus grande, mais qui améliore également les performances d’une telle éolienne. De par cette combinaison de mouvements, l’écoulement autour de cette éolienne est fortement instationnaire et nécessite une modélisation adaptée, en particulier pour tenir compte des positions initiales des pales. Le but est de présenter cette modélisation et de donner un certain nombre de résultats tels que des cartes instantanées de vecteurs vitesse ou des contours de pression, mais aussi des résultats plus globaux tels que des couples ou des coefficients de performance. http://hdl.handle.net/10985/6723 Unsteady simulation of flow in micro vertical axis wind turbine BOIS, Gérard; BAYEUL-LAINÉ, Annie-Claude Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle’s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/6723 2010-01-01T00:00:00Z BOIS, Gérard BAYEUL-LAINÉ, Annie-Claude Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle’s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied. http://hdl.handle.net/10985/6727 Numerical study of flow stream in a mini VAWT with relative rotating blades DOCKTER, Aurore; BOIS, Gérard; SIMONET, Sophie; BAYEUL-LAINÉ, Annie-Claude Today, wind energy is mainly used to generate electricity and more and more with a renewable energy source character. Power production from wind turbines is affected by several conditions like wind speed, turbine speed, turbine design, turbulence and changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the main turbine’s one. Due to this combination of movements, flow around this turbine can be more optimized than classical Darrieus turbines. The turbine has a rotor with three straight blades of symmetrical aerofoil. Paper presents unsteady simulations that have been performed for one wind velocity and different blades stagger angles. The influence of two different blades geometry is studied for four different constant rotational speeds. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10985/6727 2011-01-01T00:00:00Z DOCKTER, Aurore BOIS, Gérard SIMONET, Sophie BAYEUL-LAINÉ, Annie-Claude Today, wind energy is mainly used to generate electricity and more and more with a renewable energy source character. Power production from wind turbines is affected by several conditions like wind speed, turbine speed, turbine design, turbulence and changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the main turbine’s one. Due to this combination of movements, flow around this turbine can be more optimized than classical Darrieus turbines. The turbine has a rotor with three straight blades of symmetrical aerofoil. Paper presents unsteady simulations that have been performed for one wind velocity and different blades stagger angles. The influence of two different blades geometry is studied for four different constant rotational speeds.