Papers by Keyword: Vortex Method

Abstract: The present investigation aims to evaluate the corrosion control properties of metal matrix composites in comparison with matrix alloy using different concentration of Sodium chloride solutions and potentiodynamic polarization techniques. Matrix alloy used in ZA-27 and the reinforcement used was red mud particulates of size 50-80 microns. Composites are prepared by liquid melt metallurgy technique using vortex method. Red mud particulates reinforced varying from two to six percent by weight in steps of two percent under dry conditions. Specimens are prepared according to ASTM standards. Both composites and corresponding base alloys were subjected to identical test conditions to understand the influence of the reinforcement on alloy corrosion behaviour and effective corrosion control. Composites became less prone to corrosion and pit formation than the matrix alloy, which may be due to chemically inert red mud particles present in the metal matrix composites. On the other hand the test also reveals that corrosion resistance of both alloy and composites in crease with increase in normality of the sodium chloride solution, which may be due to increasing concentration of hydrogen ions in the solution. Corrosion of alloys can be effectively controlled by converting them in to composites by the addition of inert materials like silica particulates. If any automobile parts like bearing are made using these composites corrosion control properties can be tailored so that they can be used effectively in wide area of application.

Abstract: Although it is well known that the modes of undulatory locomotion of fish swimming provide high speed and high drive efficiency, it is hard to understand the propulsion mechanism of fish directly from living things. In the present study, in order to investigate hydrodynamic characteristics of the swimming modes, numerical simulation of flows around a deforming body of a rainbow trout which belongs to the kind of fish of subcarangiform undulatory swimmers was performed by using a Lagrangian vortex method. In this simulation, the basic configuration of the fish body is modeled with use of a NACA type airfoil, and the mode of undulatory motion is numerically given by a function obtained from observation of actual fish swimming. As a result of the present study, the relation between characteristics of propulsion force acting on the fish body and formation of complex vortex structures are clarified.