Publications

@inproceedings{Pavesi2008c,

title = {A Time-Frequency Post-Processing Technique for Characterization of the Unsteady Phenomena in the Turbomachines.},

author = {Giorgio Pavesi and Giovanna Cavazzini and Guido Ardizzon},

year  = {2008},

date = {2008-01-01},

urldate = {2008-01-01},

booktitle = {XIX Biannual Symposium on Measuring Techniques in Turbomachinery Transonic and Supersonic Flow in Cascades and Turbomachines},

volume = {MTT1908-A6},

pages = {1-5},

abstract = {This paper presented a data processing technique that combines different signal analyses for the spectral characterization of the unsteady phenomena developing in the turbomachines. Tools of the classical Fourier analysis, such as second order spectra, were combined with tools of the time-frequency analysis (wavelets, cross-wavelet, coherence wavelet functions) to identify unsteady phenomena, to define their spectral structure, to analyse their evolution in time and to determine their possible propagation direction and velocity. Because of the non-linearity of several unsteady phenomena developing in turbomachines, high-order moment functions were applied to discriminate between non-linearly coupled pulsations and self-excited pulsations and to determine the fraction of the power of each pulsation that was due to the non-linear interaction of unsteady phenomena.},

keywords = {Pump, Rotating Stall, Unsteady pressure, Wavelets},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{pop00045,

title = {Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser},

author = {Giorgio Pavesi and Guido Ardizzon and Giovanna Cavazzini},

url = {http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1576298 http://link.aip.org/link/abstract/ASMECP/v2005/i41987/p1331/s1},

doi = {10.1115/FEDSM2005-77320},

issn = {0022460X},

year  = {2005},

date = {2005-01-01},

booktitle = {2005 ASME Fluids Engineering Division Summer Meeting, FEDSM2005},

volume = {77320},

pages = {1331-1338},

publisher = {… .asmedigitalcollection.asme.org},

abstract = {Extensive research on centrifugal pumps was designed to investigate the impact of a diffuser on flow field instabilities and the noise generated by these instabilities. Activity was based upon on the cross spectral analysis of output signals from piezoelectric transducers, placed flush with the wall at the inflow and outflow of the pump, and 3D fully-viscous, unsteady computations. A pump fitted with a vaneless diffuser and a return channel was used as the test model. Flow velocity was measured in pump and diffuser inflow, to establish a link between the flow field structure and acoustic radiation. Results showed that the jet-wake flow pattern induced an unstable vortex, which influenced flow discharging from the adjacent passage, and destabilized jet-wake flow in the passage. Periodic fluctuations at the discharge of the impeller were seen as a result of this instability. Fluctuations were found to be co- herent from blade to blade, and to possess a rich harmonic content. The pressure frequency scattering by the pump was found to be consistent when compared to the experimental and analytic results, but not for the total pressure in the far field.},

note = {<b>From Duplicate 1 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, Giorgio; Ardizzon, Guido; Cavazzini, Giovanna)<br/></b><br/><b>From Duplicate 5 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/>And Duplicate 8 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/>And Duplicate 11 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 1 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 4 (<i>Unsteady flow field and noise generation in a centrifugal pump impeller with a vaneless diffuser</i> - Pavesi, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06<br/><br/><b>From Duplicate 2 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 1 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 3 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 1 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 4 (<i>Unsteady flow field and noise generation in a centrifugal pump impeller with a vaneless diffuser</i> - Pavesi, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06<br/><br/><b>From Duplicate 2 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 1 (<i>Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller With a Vaneless Diffuser</i> - Pavesi, G.; Ardizzon, G.; Cavazzini, G.)<br/></b><br/><b>From Duplicate 4 (<i>Unsteady flow field and noise generation in a centrifugal pump impeller with a vaneless diffuser</i> - Pavesi, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06},

keywords = {Acoustics, Blades, Centrifugal Pump, Computation, Diffuser, Electromagnetic scattering, Emission spectroscopy, Flow (Dynamics), Fluctuations (Physics), Impellers, Inflow, Noise (Sound), Outflow, Piezoelectric transducers, Pressure, Pump, Radiation (Physics), Radiation scattering, Scattering (Physics), Signals, Spectroscopy, Unsteady Flow, Vaneless diffusers, Vortices, Wakes},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Ardizzon1999,

title = {Modelli di Perdita nelle Turbomacchine, Previsione delle Prestazioni e Verifica Sperimentale},

author = {Guido Ardizzon and Giorgio Pavesi},

year  = {1999},

date = {1999-01-01},

urldate = {1999-01-01},

booktitle = {54° Congresso Nazionale ATI},

pages = {1397-1408},

publisher = {SGE - Padova},

abstract = {A performance prediction procedure is presented toghere with a review of loss models given in literature. Some of the original loss correlations have been modified so as to make them more directly applicable to low flow rate operation. At off-design conditions the mismatching of impeller and volute causes to vary velocity and pressure round the periphery of the impeller. This contributes significantly to the magnitude of the energy losses in the volute. The non-uniformity of the flow in the volute is taken into account by an unsteady one-dimensional method. Notwithstanding the several simplifying assumptions the results of the head capacity curve calculation agree well with the experimental results almost all over the range of operating conditions. Finelly the model supplies a basis for selecting the of parameters for optimal design of pumps in which both the maximum efficiency and the head shape are important design parameter.},

keywords = {Losses, Off-Design, Pump, Turbine, Turbomachinery},

pubstate = {published},

tppubtype = {inproceedings}

}