Bill Brey

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• Bill Brey
• M.S. Graduate Student
• Mechanical Engineering
• Office 1337 ERB
• Email wbrey_at_wisc.edu
• Hometown Grayslake, IL

Thesis Development of a Numerical Model to
Simulate Magnetic Hysteresis in an Active
Magnetic Refrigerator
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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.

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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
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Preliminary Results

• Single shot cyclic magnetization/demagnetization
  model
• Gradual temperature rise of hysteretic material
  when exposed to sinusoidal applied magnetic field

• 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