Experimental and numerical analysis of unsteady pressure pulsation in a centrifugal pump with slope volute

This study experimentally and numerically investigates the unsteady flow in a centrifugal pump with special slope volute under various conditions to illustrate the detailed flow structures and pressure pulsation within the model pump. Whole flow passage is considered during the numerical simulation; pressure pulsation signals are extracted using nine fast-response pressure transducers. The Root mean square (RMS) method is introduced to deal with the discrete components at f(BPF) of the different monitoring points along the volute casing, which is an effective attempt to evaluate the overall pulsating level of the model pump. Results show that numerical method can predict the components at f(BPF) effectively; however, it has limited ability in capturing noise frequencies motivated by unsteady separate flow and non-linear interaction effect. Around the nominal flow rate, the predicted amplitudes at f(BPF) agree well with the experimental results, showing larger difference at the off-design conditions. To predict the pulsating level of the components at f(BPF), two fitted equations of the RMS values versus the flow rate and specific speed are carried out, which would be very helpful in evaluating the pressure pulsation level in the centrifugal pump.