Bill Brey M.S. Graduate Student Mechanical Engineering Office: 1337 ERB Hometown: Grayslake, IL Thesis: Development of a Numerical Model to Simulate Magnetic Hysteresis in an Active Magnetic Refrigerator

Motivation For Research The giant magnetocaloric effect (GMCE) is a recent discovery that occurs in first order magnetic transition (FOMT) materials These materials experience a significant adiabatic temperature rise when subjected to a magnetic field These materials also experience significant hysteresis, which limits their efficiency if used in a practical AMR device. The underlying question is whether the benefit of a greater temperature change in GMCE materials outweighs the losses due to hysteresis when compared to using non-hysteretic magnetocaloric materials as refrigerants.

Project Goals Develop and implement a model of hysteresis into the existing 1D AMR numerical model created at the SEL Validate the model using experimental hysteresis data for different materials Compare performance of hysteretic FOMT materials to that of non-hysteretic magnetocaloric materials. Active Magnetic Regenerative Refrigeration Cycle

Preliminary Results Entropy Generation term is added to the energy balance equation The COP of the 1D AMR model decreases rapidly as the entropy rate is increased Single shot cyclic magnetization/demagnetization model Gradual temperature rise of hysteretic material when exposed to sinusoidal applied magnetic field