Balachandran Jeyadevan

Characterization of field-induced needle-like structures in ionic and water-based magnetic fluids

An attempt has been made to characterize the field-induced needle-like structures (secondary cluster SC) in ionic and water-based magnetic fluids (MFs) using Rayleigh light scattering technique. This technique has the advantage of detecting objects smaller than the resolution limit of the optical column. From the observations, it was found that though water is the solvent in both ionic and water-based magnetic fluids, the cluster characteristics under zero and applied magnetic field, their growth and disintegration were different.

Basic study of heat convection pipe using the developed temperature sensitive magnetic fluid

Abstract Magnetic fluids, produced using highly temperature-sensitive ultrafine ferrites coprecipitated in alkaline solution containing zinc and calcium ions, were used in the heat convection pipe. When the magnetic field was applied to the vertical pipe near the heat source, the regulated free convection made the magnetic fluid flow and transferred the thermal energy effectively.

Visual observation of the effect of magnetic field on moving air and vapor bubbles in a magnetic fluid

Abstract Theoretical prediction suggests that magnetic fluid (MF) as working liquid in heat pipe could enhance and control the heat transfer under the application of magnetic field. However, heat pipe experiments using ionic MF showed only marginal gain and demands investigation. As an initial step, visualization of air and vapor bubbles behavior under zero and applied magnetic field has been carried out using X-ray. The observations can be summarized as follows; applied magnetic field (a) reduces the size and deforms the shape of the bubble that secede from the heating surface or air supply tube, and (b) accelerates the movement of the bubble in the liquid.

Preparation and properties of low boiling point of alcohol and acetone-based magnetic fluid

Abstract Ultra-fine magnetic particles are difficult to be dispersed in low boiling point solvents such as alcohol (C 1 –C 4 ) and acetone. In this paper, we report the preparation methods of several alcohol and acetone-based magnetic fluids. The stability of magnetic fluid depended on the HLB (hydrophile–lipophile balance) of the solvent and alkyl chain lengths of organic layers. The fluid was most stable only when the HLB value of surfactant and the solvents are similar.