EXPERIMENTAL INVESTIGATION OF CAVITATION CHARACTERISTICS WITHIN A CENTRIFUGAL PUMP BASED ON ACOUSTIC ANALYSIS TECHNIQUE
Ahmed Ramadhan Al‐Obaidi
Abstract
Centrifugal pumps play an essential part in engineering systems in the process and power industries. The performance of a centrifugal pump needs to be maximized due to its importance. This depends on the flow structure within the pump, which is very complex due to the presence of a rotating impeller and its interaction with the volute casing, and mostly due to occurrence of cavitation. In this article, the results indicate that the level of acoustic amplitude is associated directly with the pump flow rate, and it increases with flow rate increases. When the cavitation inception starts, due to decreasing pressure at the eye of an impeller at high flow rate, the vapor bubbles travel to the high-pressure region inside the pump. Their collapse causes more pressure fluctuations that lead to increasing levels of noise within a pump. Continuous condition monitoring of the pump is important to increase its operational life, decrease maintenance costs and hence, enhance the reliability of the pump. During the experimental investigation, the low range of frequency between 1 Hz to 2 kHz was effective for predicting cavitation. As a result, a microphone with low range of frequency can provide a good indication to predict and diagnose cavitation, which leads to a decrease in the cost of sensor, as compared to using a microphone with high range of frequency.