2011
Pavesi, Giorgio; Dazin, Antoine; Cavazzini, Giovanna; Caignaert, Guy; Bois, Gerard; Ardizzon, Guido
Experimental and Numerical Investigation of Un-Forced Unsteadiness in a Vaneless Radial Diffuser Proceedings Article
In: ETC 9 - 9th European Turbomachinery Conference, pp. 1-12, 2011.
Abstract | BibTeX | Tags: PIV, Pump, unsteady flow fields, vaneless diffuser
@inproceedings{Pavesi2011a,
title = {Experimental and Numerical Investigation of Un-Forced Unsteadiness in a Vaneless Radial Diffuser},
author = {Giorgio Pavesi and Antoine Dazin and Giovanna Cavazzini and Guy Caignaert and Gerard Bois and Guido Ardizzon},
year = {2011},
date = {2011-01-01},
urldate = {2011-01-01},
booktitle = {ETC 9 - 9th European Turbomachinery Conference},
issue = {1989},
pages = {1-12},
abstract = {The paper reports combined experimental and numerical investigations of unforced un- steadiness in a vaneless radial diffuser. Experimental data were obtained within the diffuser using stereoscopic time resolved Particle Image Velocimetry (PIV) recording three velocity components in a plane (2D/3C), coupled with unsteady pressure transducers. To characterize the inception and the evolution of the unsteady phenomena, spectral analyses of the pressure signals were carried out both in frequency and time-frequency domains and the PIV results were post processed by an original averaging method. Two partial flow rates were investigated in detail in this paper. A single unforced unsteadiness was identified for the lowest flow rate, whereas, two competitive intermittent modes were recognized for the higher mass flow. Numerical analyses were carried out on the same pump by the commercial code CFX. All the computations were performed using the unsteady transient model and the turbulence was modelled by the Scale-Adaptive Simulation (SAS) model. Numerical pressure signals were compared with the experimental data to verify the development of the same pressure fluctuations.},
keywords = {PIV, Pump, unsteady flow fields, vaneless diffuser},
pubstate = {published},
tppubtype = {inproceedings}
}
The paper reports combined experimental and numerical investigations of unforced un- steadiness in a vaneless radial diffuser. Experimental data were obtained within the diffuser using stereoscopic time resolved Particle Image Velocimetry (PIV) recording three velocity components in a plane (2D/3C), coupled with unsteady pressure transducers. To characterize the inception and the evolution of the unsteady phenomena, spectral analyses of the pressure signals were carried out both in frequency and time-frequency domains and the PIV results were post processed by an original averaging method. Two partial flow rates were investigated in detail in this paper. A single unforced unsteadiness was identified for the lowest flow rate, whereas, two competitive intermittent modes were recognized for the higher mass flow. Numerical analyses were carried out on the same pump by the commercial code CFX. All the computations were performed using the unsteady transient model and the turbulence was modelled by the Scale-Adaptive Simulation (SAS) model. Numerical pressure signals were compared with the experimental data to verify the development of the same pressure fluctuations.
2010
Dazin, Antoine; Cavazzini, Giovanna; Pavesi, Giorgio; Dupont, Patrick; Ardizzon, Guido; CAIGNAERT, Guy; Bois, Gérard
Rotating Instabilities in a Radial Vaneless Diffuser Proceedings Article
In: 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13), pp. 1-6, 2010, ISBN: 9781617388484.
Abstract | BibTeX | Tags: Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser
@inproceedings{Dazin2010,
title = {Rotating Instabilities in a Radial Vaneless Diffuser},
author = {Antoine Dazin and Giovanna Cavazzini and Giorgio Pavesi and Patrick Dupont and Guido Ardizzon and Guy CAIGNAERT and Gérard Bois },
isbn = {9781617388484},
year = {2010},
date = {2010-01-01},
urldate = {2010-01-01},
booktitle = {13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13)},
pages = {1-6},
abstract = {The paper reports on the flow field in a vaneless diffuser of a radial flow pump at partial flow conditions. Experimental data were obtained within the diffuser using 2D/3C high repetition rate PIV coupled with unsteady pressure transducers. The pressure measurements were acquired on the shroud wall of the vaneless diffuser and on the suction pipe of the pump. Pressure signals were investigated by frequency and time frequency analyses. PIV results were post processed using original averaging methods. Two partial flow rates were investigated in detail in this paper. Rotating instability occurred for both flow rates. A single instability mode was identified for the lowest flow rate whereas, for the higher one two competitive modes were recognized intermittently. Their spatiotemporal characteristics were described in the paper.},
keywords = {Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser},
pubstate = {published},
tppubtype = {inproceedings}
}
The paper reports on the flow field in a vaneless diffuser of a radial flow pump at partial flow conditions. Experimental data were obtained within the diffuser using 2D/3C high repetition rate PIV coupled with unsteady pressure transducers. The pressure measurements were acquired on the shroud wall of the vaneless diffuser and on the suction pipe of the pump. Pressure signals were investigated by frequency and time frequency analyses. PIV results were post processed using original averaging methods. Two partial flow rates were investigated in detail in this paper. Rotating instability occurred for both flow rates. A single instability mode was identified for the lowest flow rate whereas, for the higher one two competitive modes were recognized intermittently. Their spatiotemporal characteristics were described in the paper.
2009
Cavazzini, Giovanna; Dazin, Antoine; Pavesi, Giorgio; Dupont, Patrick; Coudert, Sebastien; Ardizzon, Guido; Caignaert, Guy; Bois, Gérard
Rotating Instabilities in a Radial Vaneless Diffuser Part II : Comparison of Experimental and Numerical Results Proceedings Article
In: 8th Conference on Turbomachinery, Fluid Dynamics and Thermodynamics, pp. 1-10, 2009, ISBN: 9783851250367.
Abstract | BibTeX | Tags: Instability, Pump, Rotating Instability, Stall, vaneless diffuser
@inproceedings{Cavazzini2009,
title = {Rotating Instabilities in a Radial Vaneless Diffuser Part II : Comparison of Experimental and Numerical Results},
author = {Giovanna Cavazzini and Antoine Dazin and Giorgio Pavesi and Patrick Dupont and Sebastien Coudert and Guido Ardizzon and Guy Caignaert and Gérard Bois},
isbn = {9783851250367},
year = {2009},
date = {2009-01-01},
booktitle = {8th Conference on Turbomachinery, Fluid Dynamics and Thermodynamics},
pages = {1-10},
abstract = {The paper refers to the vaneless diffuser flow analysis of a radial flow pump in partial flow operating conditions. Numerical data obtained with the help of the CFX computer code are compared with the experimental results (high speed PIV and unsteady pressure measure- ments) presented in the first part of this paper. Averaged results and Fourier spectra are com- pared, as well as the flow patterns associated with a rotating instability occurring at this flow rate. The numerical data are also used to analyse the flow behaviour at this flow rate.},
keywords = {Instability, Pump, Rotating Instability, Stall, vaneless diffuser},
pubstate = {published},
tppubtype = {inproceedings}
}
The paper refers to the vaneless diffuser flow analysis of a radial flow pump in partial flow operating conditions. Numerical data obtained with the help of the CFX computer code are compared with the experimental results (high speed PIV and unsteady pressure measure- ments) presented in the first part of this paper. Averaged results and Fourier spectra are com- pared, as well as the flow patterns associated with a rotating instability occurring at this flow rate. The numerical data are also used to analyse the flow behaviour at this flow rate.
Dazin, Antoine; Cavazzini, Giovanna; Pavesi, Giorgio; Dupont, Patrick; Coudert, Sebastien; Ardizzon, Guido; Caignaert, Guy; Bois, Gérard
Rotating Instabilities in a Radial Vaneless Diffuser - Part I: High Speed Stereoscopic Measurements Proceedings Article
In: 8th Conference on Turbomachinery, Fluid Dynamics and Thermodynamics, pp. 1-10, 2009, ISBN: 9783851250367.
Abstract | Links | BibTeX | Tags: Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser
@inproceedings{pop00063,
title = {Rotating Instabilities in a Radial Vaneless Diffuser - Part I: High Speed Stereoscopic Measurements},
author = {Antoine Dazin and Giovanna Cavazzini and Giorgio Pavesi and Patrick Dupont and Sebastien Coudert and Guido Ardizzon and Guy Caignaert and Gérard Bois },
url = {http://www.academia.edu/download/39639243/Rotating_instabilities_in_a_radial_vaneless_diffuser_Part_I_High_speed_stereoscopic_measurements.pdf},
isbn = {9783851250367},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
booktitle = {8th Conference on Turbomachinery, Fluid Dynamics and Thermodynamics},
pages = {1-10},
abstract = {The paper refers to the behaviour of a vaneless diffuser of a radial flow pump in partial flow operating conditions. Experimental data have been obtained within the diffuser using 2D/3C high repetition rate PIV coupled with unsteady pressure transducers. The pressure measurements were acquired on the shroud wall of the vaneless diffuser and on the suction pipe of the pump. Various operating conditions were investigated in order to characterize the unsteady flow field especially at partial flow rates when the rotating instability appears. A Fourier analysis has been carried out both on the pressure and velocity signals to identify the characteristics of the rotating instability. Averaged results of the PIV data allowed the topology of the instability cells to be visualized and described. Nomenclature},
keywords = {Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser},
pubstate = {published},
tppubtype = {inproceedings}
}
The paper refers to the behaviour of a vaneless diffuser of a radial flow pump in partial flow operating conditions. Experimental data have been obtained within the diffuser using 2D/3C high repetition rate PIV coupled with unsteady pressure transducers. The pressure measurements were acquired on the shroud wall of the vaneless diffuser and on the suction pipe of the pump. Various operating conditions were investigated in order to characterize the unsteady flow field especially at partial flow rates when the rotating instability appears. A Fourier analysis has been carried out both on the pressure and velocity signals to identify the characteristics of the rotating instability. Averaged results of the PIV data allowed the topology of the instability cells to be visualized and described. Nomenclature
2008
Cavazzini, Giovanna; Dazin, Antoine; Pavesi, Giorgio; Dupont, P.; Coudert, S.; Caignaert, Guy; Bois, Gerard; Ardizzon, Guido
Rotating Instabilities in a Radial Vaneless Diffuser Journal Article
In: IAHR 24th Symposium on Hydraulic Machinery and Systems, pp. 1-10, 2008.
Abstract | BibTeX | Tags: Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser
@article{Cavazzini2008,
title = {Rotating Instabilities in a Radial Vaneless Diffuser},
author = {Giovanna Cavazzini and Antoine Dazin and Giorgio Pavesi and P. Dupont and S. Coudert and Guy Caignaert and Gerard Bois and Guido Ardizzon },
year = {2008},
date = {2008-01-01},
urldate = {2008-01-01},
journal = {IAHR 24th Symposium on Hydraulic Machinery and Systems},
pages = {1-10},
abstract = {The paper reports on experimental and numerical investigations of large-scale instabilities in a vaneless diffuser of a radial flow pump. The flow field structures were analysed at off-design operating conditions by a stereoscopic time resolved PIV technique and pressure transducers, placed flush with the diffuser walls. Spectral analyses were carried out both on the velocity and pressure signals to identify the characteristics of the instabilities. The experimental data were compared with the numerical results obtained by ANSYS CFX computer code to study the evolution of the flow field instabilities at part load. The numerical computation was performed on the entire pump with the transient sliding faces and the turbulence DES model. The leakage effects were taken into account. The time step for the calculations was chosen according to a runner rotation of about 1 degree.},
keywords = {Analysis, Flow instability, Numerical Analysis, part load, PIV, radial flow pump, spectral, vaneless diffuser},
pubstate = {published},
tppubtype = {article}
}
The paper reports on experimental and numerical investigations of large-scale instabilities in a vaneless diffuser of a radial flow pump. The flow field structures were analysed at off-design operating conditions by a stereoscopic time resolved PIV technique and pressure transducers, placed flush with the diffuser walls. Spectral analyses were carried out both on the velocity and pressure signals to identify the characteristics of the instabilities. The experimental data were compared with the numerical results obtained by ANSYS CFX computer code to study the evolution of the flow field instabilities at part load. The numerical computation was performed on the entire pump with the transient sliding faces and the turbulence DES model. The leakage effects were taken into account. The time step for the calculations was chosen according to a runner rotation of about 1 degree.
