| Issue |
La Houille Blanche
Number 3-4, Juin 1998
|
|
|---|---|---|
| Page(s) | 128 - 133 | |
| DOI | https://doi.org/10.1051/lhb/1998050 | |
| Published online | 01 August 2009 | |
Matrice de transfert et sources hydroacoustiques d'une pompe centrifuge à faibles charges
Transmission matrix and hydroacoustic sources of a centrifugal pump at very low load
EDF/DER, Département Machines
Abstract
Transmission matrix and hydroacoustic sources of a centrifugal pump, at very low load, are determined by an experimental method ; with an external excitation (f1ow fluctuations generated by a small rotating valve connected on a by-pass around the machine), more important than the hydroacoustic sources of the pump (even at very low load), the transmission matrix is accurately determined. Then pump sources are obtained by a simple difference. The main results are :
- in terms of load, no variation of the transmission matrix,
- about hydroacoustic sources, under a particular load (beginning of recirculation phenomena), spectra are distorted and the peak amplitude at the blade passing frequency (and multiples) increases appreciably,
- at low load, wide band noise becomes important (x20), and this has a very bad influence on arounding pipes, because their hydroacoustic modes are necessarily excited.
© Société Hydrotechnique de France, 1998