抄録
In order to clarify an internal flow of regenerative pump, velocity measurements have been conducted by PIV (Particle Image Velocimetry) for the pump with casing and impeller made of acrylic resin. Spiral flows that come and go between the flow passage and impeller are confirmed. On the cross section parallel to the rotating plate of impeller, when the flow rate is small (i.e., the pump head is large), the magnitude of radial velocity becomes larger and the circumferential velocity smaller than the case of large flow rate. It is, therefore, considered that the number of turns of spiral flow between the flow passage and the impeller increase, and so the pump head also increase when the flow rate is small.
