Abstract
An application of contra-rotating rotors has been proposed in response to a demand for the higher specific speed of axial flow pump. The internal flow field and blade rows interactions between the front and rear rotors should be considered in the design for higher performance and more stable operation. In our previous study, at the partial flow rates, we have observed the positive slope of H-Q curve in the rear rotor, while we expect the negative slope because of the lower blade loading of the rotors compared with the usual axial flow pump rotor. Then, in the present study, for more understanding of the internal flow at the partial flow rate, we investigate the internal flow fields by Laser Doppler Velocimetry measurement and the limiting streamline observation with the Oil-film method.
