Utility of Acoustic Detection in Hydraulic Machinery

Abstract

Optimised energy production from hydraulic machinery is dependant both on the care taken during the design and construction phases and on the ability to ensure optimal operating conditions. When machinery is affected by cavitation, performance levels fall and can rapidly deteriorate altogether, a phenomenon which makes it essential to identify the onset of cavitation using effective detection methods. In the present paper the analysis conducted on the basis of acoustic measurements (characterized by non intrusive technology) displays a particular sensitivity, making it suitable for detecting the phases of cavitation onset. The experimental measurements point out the presence of a marked increase in the spectral power density curve of the noise signal, especially in the high frequency range. Moreover the acoustic method also makes it possible to detect different nuclei of cavitation in the machinery under the same operating conditions (which is not achieved by other methods). These characteristics of the acoustic method are of particular interest to managers of working systems (with a view to verifying whether the working conditions can trigger cavitation) as well as to the manufacturers of hydraulic machinery (both in the design and in the production phase)