Heat Transfer Characteristics of a Thermo-sensitive Magnetic Fluid in Micro-channel

Abstract

In the present study, the flow characteristics and heat transfer of a thermo-sensitive magnetic fluid, which is a multiphase-flow material, were investigated experimentally. The mini-channels considered herein have a depth of 0.5 mm, with the nominal channel width being equal to five times the depth. The channel device was constructed from a Teflon tube. The operation of the device is based on the thermo-magnetic characteristics of the fluid, a suspension of Mn-Zn ferrite particles in kerosene, the magnetization of which is known to decrease with increasing temperature. The experimental parameters were magnetic force, the position of the magnet, and the temperature of the magnetic fluid. The experimental results indicate that force convection based on the magnetic characteristics of the fluid in the mini-channel exhibits excellent cooling performance. Furthermore, the flow characteristic of the thermo-sensitive magnetic fluid was found to be strongly dependent on the magnetic condition, such as the force and the position.

Keywords

• thermo-sensitive magnetic fluid
• heat transfer
• micro-channel