A blood flow simulator is one of the most useful tools for investigating the dynamic properties of a cardiovascular system. The blood pump in a blood flow simulator generates pulsating flows by oscillating a membrane mechanically at different pulse rates. To evaluate the performance of the blood pump properly, the flow characteristics of the pulsating flows should be considered. In this paper, two basic indicators for evaluating the blood pump characteristics, the output power and the overall efficiency, were determined with consideration of the pulsating flows, based on a phase-averaged analysis. These indicators were obtained by integrating closed contours in a $P-Q$ diagram. The measured output power was expected to be meaningful for understanding the dynamic effects caused by pulsating flows.