Journal of Applied Mechanical Engineering

Thermomagnetic convection as a novel heat transfer mode in electronics cooling

Global Summit and Expo on Fluid Dynamics & Aerodynamics

August 15-16, 2016 London, UK

Sumanta Banerjee

Heritage Institute of Technology, Kolkata

Posters & Accepted Abstracts: J Appl Mech Eng

Abstract:

Ferro fluids behave as electrically non-conducting, isotropic, homogeneous continua and combine the dual attributes of magnetic response and liquid flow ability. When subjected to external magnetic fields, the particle magnetic moment vectors align with the (applied) field direction without hysteresis. For all values of the magnetic field strength, the magnetization behaviour can be described by the Langevin function, which is characterized by a high initial susceptibility at low to moderate fields followed by a low susceptibility due to magnetic saturation. This super paramagnetic behaviour can be harnessed to establish flow in devices through external positioning and control of magnetic fields without the aid of movable parts. Externally imposed and controllable magnetic field gradients, coupled with thermally induced ferro-fluid susceptibility gradients (e.g. by boundary heating from localized heat sources), result in thermomagnetic convection. Under externally-applied magnetic field and temperature gradients, thermomagnetic transport can initiate advective motion without external pumping action. It causes heat removal from the sites of �??hot-spots�?� of devices through active �??participation�?� by the heat sources themselves. Thermomagnetic convection can, therefore, be used as a viable heat transfer method in microgravity environments, or serve as a novel mechanism to augment free convection in electronics cooling. This convection mechanism also aids in designing self-regulating and self-sustaining thermo syphon-type passive cooling systems for electronics cooling, where the pertinent small length scales render buoyancy-aided convection rather ineffective.

Biography :

Email: sumanta.banerjee@heritageit.edu