A challenge to develop an inexpensive "spiral vortex pump"

Tomohiro Tsujimoto, Kiyotaka Iwasaki, Wataru Saeki, Kei Yoshida, Makoto Arita, Mitsuo Umezu, Yi Qian, Chun Xiu Ye, Kou Imachi, Kazuhiko Ishihara, Takashi Tanaka