CAVITATION INTENSITY MEASUREMENT BY ANALYSIS OF PUMP STRUCTURE OSCILLATION-A NEW PARAMETRIC METHOD APPROACH

One of the sources of instability in pumps is cavitation phenomenon. Cavitation in a pump can cause some undesirable effects, such as deterioration of the hydraulic performance (drop in head-capacity and efficiency curves), damage of the pump by pitting and erosion, structure vibration and resulting noise. Cavitation can appear within the entire range of operating conditions; therefore its occurrence inside a pump and its intensity must, by all means, be identified. In the present study, alternations in the velocity of an axial flow pump structure, for the first time used to investigate Cavitation. An average energy method for identification cavitation occurrence and measurement its intensity has been developed. This is called the Logarithmic Cavitation Intensity (LCI). To establish the pump cavitation conditions, a statistical analysis has been undertaken in a real-time and an LCI has been recommended as a proper criterion for defining the cavitation intensity. The results also showed the proposed method besides some other advantages comparing other detection methods, is feasible by simple hardware with low sampling frequency resulting in reducing the computational time as well as hardware complexity and cost.