scispace - formally typeset
Search or ask a question
Author

Tatsuo Nishimura

Bio: Tatsuo Nishimura is an academic researcher from Hiroshima University. The author has contributed to research in topics: Open-channel flow & Turbulence. The author has an hindex of 8, co-authored 11 publications receiving 504 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the authors investigated flow characteristics in a channel with a symmetric wavy wall and showed that the variation of pressure drop and wall shear stress with the Reynolds number was elucidated by the behavior of the circulated vortex formed at the diverging cross section of the channel.
Abstract: Flow characteristics in a channel with a symmetric wavy wall were investigated by calculations and experiments. The channel used has a geometry similar to that of the Oxford membrane blood oxygenator. The flow regime covered ranged from laminar to turbulent flow. The variation of pressure drop and wall shear stress with the Reynolds number was elucidated by the behavior of the circulated vortex formed at the diverging cross section of the channel.

176 citations

Journal ArticleDOI
TL;DR: In this article, the boundary layer solution predicting the heat transfer rate is derived on the basis of the numerical results, and it is shown that the Nusselt number is inversely proportional (1 + N) where N is the number of partitions.

91 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the mass transfer characteristics of a symmetric wavy channel with a geometry similar to that of the Oxford membrane blood oxygenator and found that the reversed flow region significantly differs from the forward flow region in mass transfer.
Abstract: Mass transfer characteristics in a channel with symmetric wavy wall were investigated by the Leveque theory and the electrochemical method. The channel used has a geometry similar to that of the Oxford membrane blood oxygenator. The flow regime covered ranged from laminar to turbulent flow. The local Sherwood number distributions indicate that the reversed-flow region significantly differs from the forward-flow region in mass transfer characteristics. For laminar flow, mass transfer enhancement of the wavy channel is scarcely expected as compared with the corresponding straight channel, but is found to be remarkable for turbulent flow.

69 citations

Journal ArticleDOI
TL;DR: In this paper, experimentaux experimentaux de perte de charge, de diagramme d'ecoulement and de transfert de matiere were experimentaux for diagrammées.
Abstract: Resultats experimentaux de perte de charge, de diagramme d'ecoulement et de transfert de matiere

68 citations

Journal ArticleDOI
TL;DR: The relationship between flow structure and mass transfer in a wavy channel was investigated in the range from laminar to turbulent flow in this paper, and a remarkable increment of mass transfer rate was induced near the flow reattachment point in the large recirculation vortex, which suggests a renewal of the concentration boundary layer because of the flow intermittency.
Abstract: The relationship between flow structure and mass transfer in a wavy channel was investigated in the range from laminar to turbulent flow. Laminar flow has a steady two-dimensional structure, but turbulent flow has an unsteady three-dimensional vortical structure. In particular, the flow field in a large recirculation vortex within the furrow of a wavy wall shows an intermittent reversed flow and a nonuniformity of flow in the spanwise direction for turbulent flow. The flow intermittency is closely related to the mass transfer, and a remarkable increment of mass transfer rate is induced near the flow reattachment point in the large recirculation vortex, which suggests a renewal of the concentration boundary layer because of the flow intermittency.

49 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, the authors studied the rate of heat transfer for flow through a periodic array of wavy passages with an accurate numerical scheme, and observed that self-sustained oscillations lead to the destabilization of laminar thermal boundary layers, replenish the nearwall fluid with the fluid in the core region, and thus provide a natural mechanism of heat and mass transfer enhancement.

303 citations

Journal ArticleDOI
TL;DR: In this article, local heat transfer and flow behavior for laminar and transitional flows in sinusoidal wavy passages are investigated, with special attention directed toward detecting the onset of macroscopic mixing in the flow.

293 citations

Journal ArticleDOI
TL;DR: In this paper, the authors considered sinusoidal corrugated-plate channels with uniform wall temperature and single-phase constant property flows and obtained numerical solutions using the control-volume finite-difference method for a wide range of channel corrugation aspect ratios and flow rates.

207 citations

Journal ArticleDOI
TL;DR: Oscillatory flow reactors (OFRs) offer a suitable platform to deliver consistent operating conditions under plug-flow operation while maintaining a controlled steady state as discussed by the authors, which is an attractive approach for the delivery of consistent particles with specified critical quality attributes (CQAs).

164 citations

Journal ArticleDOI
TL;DR: In this article, experimental observations on the dispersion of fluid in horizontal and vertical tubes where periodic baffles and fluid oscillation may be present were made both at the center and wall of the tube.

158 citations