naa a22 4500 510766129 CHVBK 20180411083157.0 cr unu---uuuuu 180411e20130801xx s 000 0 eng 10.1007/s11630-013-0634-x doi (NATIONALLICENCE)springer-10.1007/s11630-013-0634-x Experimental analysis of flow structure in contra-rotating axial flow pump designed with different rotational speed concept [Elektronische Daten] [Linlin Cao, Satoshi Watanabe, Toshiki Imanishi, Hiroaki Yoshimura, Akinori Furukawa] As a high specific speed pump, the contra-rotating axial flow pump distinguishes itself in a rear rotor rotating in the opposite direction of the front rotor, which remarkably contributes to the energy conversion, the reduction of the pump size, better hydraulic and cavitation performances. However, with two rotors rotating reversely, the significant interaction between blade rows was observed in our prototype contra-rotating rotors, which highly affected the pump performance compared with the conventional axial flow pumps. Consequently, a new type of rear rotor was designed by the rotational speed optimization methodology with some additional considerations, aiming at better cavitation performance, the reduction of blade rows interaction and the secondary flow suppression. The new rear rotor showed a satisfactory performance at the design flow rate but an unfavorable positive slope of the head — flow rate curve in the partial flow rate range less than 40% of the design flow rate, which should be avoided for the reliability of pump-pipe systems. In the present research, to understand the internal flow field of new rear rotor and its relation to the performances at the partial flow rates, the velocity distributions at the inlets and outlets of the rotors are firstly investigated. Then, the boundary layer flows on rotor surfaces, which clearly reflect the secondary flow inside the rotors, are analyzed through the limiting streamline observations using the multi-color oil-film method. Finally, the unsteady numerical simulations are carried out to understand the complicated internal flow structures in the rotors. Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg, 2013 Contra-rotating rotors nationallicence Internal flow nationallicence Limiting streamlines nationallicence Tip leakage vortex nationallicence Corner separation nationallicence Cao Linlin Graduate School of Engineering, Kyushu University, Kyushu, Japan aut Watanabe Satoshi Department of Mechanical Engineering, Kyushu University, Kyushu, Japan aut Imanishi Toshiki Graduate School of Engineering, Kyushu University, Kyushu, Japan aut Yoshimura Hiroaki Graduate School of Engineering, Kyushu University, Kyushu, Japan aut Furukawa Akinori Oita National College of Technology, Oita, Japan aut Journal of Thermal Science Springer Berlin Heidelberg 22/4(2013-08-01), 345-351 1003-2169 22:4<345 2013 22 11630 https://doi.org/10.1007/s11630-013-0634-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11630-013-0634-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cao Linlin Graduate School of Engineering, Kyushu University, Kyushu, Japan aut NATIONALLICENCE 700 1- Watanabe Satoshi Department of Mechanical Engineering, Kyushu University, Kyushu, Japan aut NATIONALLICENCE 700 1- Imanishi Toshiki Graduate School of Engineering, Kyushu University, Kyushu, Japan aut NATIONALLICENCE 700 1- Yoshimura Hiroaki Graduate School of Engineering, Kyushu University, Kyushu, Japan aut NATIONALLICENCE 700 1- Furukawa Akinori Oita National College of Technology, Oita, Japan aut NATIONALLICENCE 773 0- Journal of Thermal Science Springer Berlin Heidelberg 22/4(2013-08-01), 345-351 1003-2169 22:4<345 2013 22 11630 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer