title: Hydrodynamic characteristics of the helical flow pump.
abstract: The helical flow pump (HFP) was invented to be an ideal pump for developing the TAH and the helical flow TAH (HFTAH) using two HFPs has been developed. However, since the HFP is quite a new pump, hydrodynamic characteristics inside the pump are not clarified. To analyze hydrodynamic characteristics of the HFP, flow visualization study using the particle image velocimetry and computational fluid dynamics analysis were performed. The experimental and computational models were developed to simulate the left HFP of the HFTAH and distributions of flow velocity vectors, shear stress and pressure inside the pump were examined. In distribution of flow velocity vectors, the vortexes in the vane were observed, which indicated that the HFP has a novel and quite unique working principle in which centrifugal force rotates the fluid in the helical volutes and the fluid is transferred from the inlet to the outlet helical volutes according to the helical structure. In distribution of shear stress, the highest shear stress that was considered to be occurred by the shunt flow across the impeller was found around the entrance of the inlet helical volute. However, it was not so high to cause hemolysis. This shunt flow is thought to be improved by redesigning the inlet and outlet helical volutes. In distribution of pressure, negative pressure was found near the entrance of the inlet helical volute. However, it was not high. Negative pressure is thought to be reduced with an improvement in the design of the impeller or the vane shape.
authors.affiliation: Department of Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, ishii@bme.gr.jp.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ishii
authors.forename: Kyohei
authors.initials: K
authors.lastname: Hosoda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishida
authors.forename: Takashi
authors.initials: T
authors.lastname: Isoyama
authors.forename: Itsuro
authors.initials: I
authors.lastname: Saito
authors.forename: Koki
authors.initials: K
authors.lastname: Ariyoshi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Inoue
authors.forename: Toshiya
authors.initials: T
authors.lastname: Ono
authors.forename: Hidemoto
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Masami
authors.initials: M
authors.lastname: Sato
authors.forename: Sintaro
authors.initials: S
authors.lastname: Hara
authors.forename: Xinyang
authors.initials: X
authors.lastname: Lee
authors.forename: Sheng-Yuan
authors.initials: SY
authors.lastname: Wu
authors.forename: Kou
authors.initials: K
authors.lastname: Imachi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Abe
mesh_terms: D001243:Assisted Circulation / Q000295:instrumentation*; D003198:Computer Simulation; D004867:Equipment Design; D006354:Heart, Artificial; D018056:Hemorheology; D006801:Humans; D008955:Models, Cardiovascular; D012212:Rheology; D013314:Stress, Mechanical