naa a22 4500 510765831 CHVBK 20180411083156.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1007/s11630-013-0665-3 doi (NATIONALLICENCE)springer-10.1007/s11630-013-0665-3 Counter-rotating type tidal stream power unit boarded on pillar (performances and flow conditions of tandem propellers) [Elektronische Daten] [Yuta Usui, Toshiaki Kanemoto, Koju Hiraki] The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fruitful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propellers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger. Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg, 2013 Tidal stream nationallicence Counter rotation nationallicence Tandem propellers nationallicence Generator nationallicence Armature nationallicence Usui Yuta Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut Kanemoto Toshiaki Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut Hiraki Koju Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut Journal of Thermal Science Springer Berlin Heidelberg 22/6(2013-12-01), 580-585 1003-2169 22:6<580 2013 22 11630 https://doi.org/10.1007/s11630-013-0665-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11630-013-0665-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Usui Yuta Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut NATIONALLICENCE 700 1- Kanemoto Toshiaki Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut NATIONALLICENCE 700 1- Hiraki Koju Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, 804-8550, Fukuoka, Japan aut NATIONALLICENCE 773 0- Journal of Thermal Science Springer Berlin Heidelberg 22/6(2013-12-01), 580-585 1003-2169 22:6<580 2013 22 11630 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer