Design Optimization of Magnetic Fluid Cooling System

This paper introduces topology design optimization for a magnetically controlled convective heat transfer cooling system. It is well known that a stationary magnetic field subjected to a temperature gradient generates fluid motion in a magnetic fluid (e.g. ferrofluid). This physical phenomenon may be exploited to drive convective motion in the cooling system to maximize the heat transfer performance. Here, the magnetic field source layout of the system is designed to enhance the heat transfer performance. More specifically, the distribution and magnetization direction of the permanent magnet (PM) field source is optimized to minimize the maximum temperature of a closed loop heat transfer system. The design optimization is performed using a gradient-based topology optimization method with a fully coupled non-linear analysis for magnetic-thermal-fluid systems. Interestingly, magnet designs similar to Halbach arrays are obtained as the optimal PM layout. The magnetic field distribution generated by the designed layout affects the body force that the fluid is subjected to and results in unique fluid flow patterns for maximum cooling performance of the system. Thus, this paper will provide an explanation of the design optimization procedure and provide the design result.