Akira Tanimoto

Bio: Akira Tanimoto is an academic researcher from Kanazawa University. The author has contributed to research in topics: Laminar flow & Thermal conduction. The author has an hindex of 7, co-authored 20 publications receiving 152 citations.

Performance of Counterflow, Parallel Plate Heat Exchangers under Laminar Flow Conditions

Abstract: Multilayered heat exchangers were analyzed theoretically and their heat transfer characteristics were clarified. The problem was treated as a two-dimensional, conjugated one with three phases-two fully developed laminar flows and the exchanger wall. From numerical results, the exchanger effectiveness was found to be definitely influenced by the following parameters: Graetz number, heat capacity flow rate ratio, dimensionless wall thickness, and conductance ratios between fluid and wall and between both fluids. Examination of mixed-mean temperature distributions in the exchanger showed that longitudinal wall conduction significantly reduces exchanger effectiveness in the low-Graetz-number region. Experimental results were in fairly good agreement with theoretical predictions.

Conjugate heat transfer with laminar flow in an annulus

Abstract: The solution to the conjugate heat transfer problem in an annulus with a heated (cooled) core and an insulated outside tube is presented. Three kinds of boundary conditions are considered for a chosen radius ratio. From the results of parametric calculation over a wide range, it is concluded that wall heat conduction in a core can have substantial effects on the heat transfer characteristics in the areas surrounding the beginning and the end of the heat transfer section. On presente une resolution du probleme de transfert de chaleur conjugue dans un espace annulaire ou le noyau est chauffe (ou refroidi) et la paroi exterieure isolee. Trois types de conditions limites sont consideres pour un rapport de rayon fixe. Les resultats du calcul parametrique sur une large gamme de variations de parametres permettent de conclure que la conduction de chaleur parietale dans le noyau peut avoir des effets importants sur les caracteristiques du transfert de chaleur au debut et a la fin de la section ou s'effectue le transfert.

Magnetic Field Effects on Copper Electrolysis

Abstract: The effect of a static magnetic field, B, on the electrolysis of copper in aqueous solution is investigated using linear sweep voltammetry, impedance spectroscopy, chronoamperometry, rotating disk voltammetry, and analysis of fractal growth patterns. Data are obtained in fields of up to 6 T. There is a large enhancement of the electrodeposition rate (up to 300%) from concentrated CuSO4 solution (c ∼1 M) when pH ≤ 1. The effect of the magnetic field is equivalent to that achieved by rotating the electrode. From the pH, viscosity, field direction and concentration dependence of the field effect, the influence of field on the complex impedance, and the equivalence of field and electrode rotation, it is established that the magnetic field influences mass transport by forced convection. Convective flow is modified on a microscopic scale in the boundary layer close to the working electrode. There is no influence on the electrode kinetics. Turbulence sets in for our cell geometry when the product of field and cu...

Wetting phenomena and time of wetness in atmospheric corrosion: a review

Abstract: Abstract The concept of time of wetness (TOW) is extensively used in the atmospheric corrosion disciplines for such purposes as corrosion prognostics and environmental corrosivity classification. Time of wetness can generally be defined as the amount of time a metal surface remains wet during atmospheric exposure. Although the basic concept and importance of TOW in governing atmospheric corrosion is generally agreed upon, what is meant by “wet” has generally remained ambiguous and its practical determination has been widely varied throughout its history. The objective of this review is to demystify TOW in terms of definition and measurement and identify issues that inhibit this parameter from providing deeper insight into the effect wetness duration has on atmospheric corrosion. Specifically, this paper summarizes the current state of TOW determination methods along with the parallel concept leaf wetness used in environmental science. Furthermore, wetting and drying phenomena associated with atmospheric corrosion and thought to control TOW are overviewed. From this framework, current issues and limitations of TOW are identified and avenues for further improvement suggested.