Detection of incipient cavitation and determination of the best efficiency point for centrifugal pumps using acoustic emission

Alfayez, L.

doi:10.1243/095440805x33225

Cited by 35 publications

(40 citation statements)

References 11 publications

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“…Results of this study also showed that the measurement of AE r.m.s levels could be employed for determining the BEP of pumps which offers enormous opportunities within the industry. Sikorska and Hodkiewicz [101] reiterated the observations of Alfayez [99,100] noting that AE was able to detect off duty conditions in double suction pumps. Furthermore Sikorska and Hodkiewicz noted that AE could be used to detect cavitation and recirculation and postulated that low flow AE activity was initiated by recirculation whilst high flow AE activity was due to incipient cavitation.…”

Section: Pumps and Acoustic Emission Technologymentioning

confidence: 98%

“…The presence of cavitation has been shown to increase operational AE noise levels. Recently Alfayez et al [99,100] undertook experimental tests on a range of pumps in an attempt to correlate incipient cavitation with AE activity. Results showed a clear relationship between AE activity measured from the pump casing, suction and discharge pipes, and incipient cavitation.…”

Section: Pumps and Acoustic Emission Technologymentioning

confidence: 99%

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Development of Acoustic Emission Technology for Condition Monitoring and Diagnosis of Rotating Machines: Bearings, Pumps, Gearboxes, Engines, and Rotating Structures

Mba¹,

Rao²

2006

The Shock and Vibration Digest

267

129

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One of the earliest documented applications of Acoustic Emission Technology (AET)to rotating machinery monitoring was in the late 1960s. Since then there has been an explosion in research and application based studies covering bearings, pumps, gearboxes, engines and rotating structures. This paper presents a comprehensive and critical review to date on the application of Acoustic Emission Technology to condition monitoring and diagnostics of rotating machinery. of surface asperities and impingement of the bearing rollers over a defect on an outer race will result in the generation of acoustic emission. These emissions propagate on the surface of the material as Rayleigh waves and the displacement of these waves is measured with an AE sensor. Rayleigh waves are a combination of longitudinal and transverse waves [4]. It should be noted that surface defects such as cracks and scratches attenuate rayleigh waves, in addition, the surface finish of metals can also influence attenuation [4].Judicious application of well-tried and tested acoustic emission technology can provide powerful diagnostic capabilities, which are safe, efficient and cost-effective. This paper reviews the research and development activities that are being pursued in the following subject areas; bearings (roller and hydrodynamic), gearboxes, pumps, machinery and mechanical seals.Acoustic emission (AE) was originally developed for non-destructive testing of static structures, however, over the last 35 years its application has been extended to health monitoring of rotating machines, including bearings, gearboxes, pumps, etc. It offers the advantage of earlier defect/failure detection in comparison to vibration analysis due to the increased sensitivity offered by AE. However, limitations in the successful application of AE technique for monitoring the performance of a wide range of rotating machinery have been partly due to the difficulty in processing, interpreting and classifying the intelligent information from the acquired data. The main drawback with the application of the AE technique is the attenuation of the signal and as such 3 the AE sensor has to be close to its source. However, it is often practical to place the AE sensor on the non-rotating member of the machine, such as the bearing or gear casing. Therefore, the AE signal originating from the defective component will suffer severe attenuation, and reflections, before reaching the sensor. AE covers a wide frequency range (100 kHz to 1MHz) and time domain waveforms associated with AE are of two types; burst and continuous. A continuous type AE refers to a waveform where transient bursts are not discernible [5]. Both waveform types are associated with rotating machinery, for instance, a continuous type emission may be as a result of turbulent fluid flow within a peep while a burst type could be associated with transient rolling action of meshing bears. On rotating machinery typical background operational noise is of a continuous type. Traditionally the most commonly measured AE parameters ...

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Section: Pumps and Acoustic Emission Technologymentioning

confidence: 98%

Section: Pumps and Acoustic Emission Technologymentioning

confidence: 99%

Development of Acoustic Emission Technology for Condition Monitoring and Diagnosis of Rotating Machines: Bearings, Pumps, Gearboxes, Engines, and Rotating Structures

Mba¹,

Rao²

2006

The Shock and Vibration Digest

267

129

View full text Add to dashboard Cite

show abstract

“…Acceleration signals have also been exploited for the detection of cavitation in centrifugal and gerotor pumps [8,9]; for this purpose, noise measurements have also often been considered [10,11].…”

Section: Introductionmentioning

confidence: 99%

A Methodology Based on Cyclostationary Analysis for Fault Detection of Hydraulic Axial Piston Pumps

Casoli¹,

Bedotti²,

Campanini³

et al. 2018

Energies

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Condition monitoring has been an active area of research in many industrial fields during the last decades, particularly in fluid power systems. This paper presents a solution for the fault diagnosis of a variable displacement axial-piston pump, which is a critical component in many hydraulic systems. The proposed methodology follows a data-driven approach including data acquisition and feature extraction and is based on the analysis of acceleration signals through the theory of cyclostationarity. An experimental campaign was carried out on a laboratory test bench with the pump in the flawless state and in faulty states. Different operating conditions were considered and each test was repeated several times in order to acquire a suitable population to verify data repeatability. Results showed the capability of the proposed approach of detecting a typical fault related to worn slippers. Future works will include tests in order to apply the approach to a wider set of faults and the development of a classifier for accurate fault identification.

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“…In addition they observed that the audible noise of the pump decreased upon onset of cavitation. Alfayez and Mba (2004) Al Thobiani et al (2011) reported the results of experiments to predict the onset of cavitation using a range of statistical parameters derived from: the vibration signal obtained from an accelerometer on the pump casing. The airborne acoustic signal from a microphone close to the outlet of the pump and the waterborne acoustic signal from a hydrophone in the outlet pipe close to the pump were recorded.…”

Section: Introductionmentioning

confidence: 99%

Acoustic Detection of Cavitation Inception

Abdelaziz¹,

Selim

2017

JAFM

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Cavitation phenomenon can cause deterioration of the hydraulic performance, damage by pitting, material erosion, structure vibration and noise in fluid machinery, turbo-machinery, ship propellers and in many other applications. Therefore, it is important to detect inception of cavitation phenomenon. An experimental study has been carried out in order to investigate the noise radiated by various cavitating sources to determine the validity of noise measurements for detecting the onset of cavitation. Measurements have been made measuring the noise radiated by a number of configurations in a water tunnel at various operating condition to determine the onset of cavitation. The measurements have been conducted over a frequency range of 31.5 Hz to 31.5 kHz in one-third octave bands. The onset of cavitation was measured visually through a Perspex side of the working section of the water tunnel. Moreover, a theoretical estimate of the pressure radiated from the cavitation nuclei at their critical radii and their frequency was presented. Tests indicated that, generally, at the point of visual inception there was a marked rise of the sound pressure level in the high-frequency noise, whilst the low-frequency noise increased as the cavitation developed. This finding was supported by the theoretical estimate of the pulsating frequency of cavitation nuclei. The results illustrated that the visual observations of inception confirm the noise measurements.

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Detection of incipient cavitation and determination of the best efficiency point for centrifugal pumps using acoustic emission

Cited by 35 publications

References 11 publications

Development of Acoustic Emission Technology for Condition Monitoring and Diagnosis of Rotating Machines: Bearings, Pumps, Gearboxes, Engines, and Rotating Structures

Development of Acoustic Emission Technology for Condition Monitoring and Diagnosis of Rotating Machines: Bearings, Pumps, Gearboxes, Engines, and Rotating Structures

A Methodology Based on Cyclostationary Analysis for Fault Detection of Hydraulic Axial Piston Pumps

Acoustic Detection of Cavitation Inception

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