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Transient Induction Heating Simulation with BH Curve Material
Posted 2025/03/27 11:18 GMT-4 Electromagnetics, Modeling Workflow Version 6.2 2 Replies
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Dear respected experts,
I am encountering difficulties in simulating an induction heating process and would appreciate your guidance. The configuration consists of a U-shaped single-turn coil carrying AC current to heat a soft magnetic material plate via induction.
The key technical issue is: When defining the soft magnetic material's constitutive relation using a BH curve, frequency-domain analysis becomes unavailable. However, when switching to transient calculation, I cannot apply current excitation to the single-turn coil. Attempting voltage excitation results in severe convergence issues.
Core requirements:
Maintain BH curve definition (necessary for accurate hysteresis loss calculation)
Perform transient analysis with AC current in U-shaped coil
Constraints observed:
Relative permeability models cannot replicate measured hysteresis losses
Experimental data confirms hysteresis loss dominates over eddy current loss in this heating process
Has anyone successfully implemented such a combination (BH curve material + transient AC current excitation for single-turn coils)? Any suggestions on solver settings/excitation implementation would be highly valuable.
Attachments:
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Hi,
Note that the built-in material models for B-H curve (stationary and transient) and Effective B-H curve (frequency domain) only account for the magnetic saturation effect. To account for hysteresis, you need to use the Hysteresis Jiles-Atherton model in the time domain or use a measured lookup table for the losses as a function of magnetic flux density magnitude and temperature in the frequency domain. In general, I would expect it to be challenging to measure/extract Jiles-Atherton parameters as a function of temperature, especially in the higher temperature range. The current driven solid conductor coil typically results in numerical difficulties in the time domain, especially if you try to ramp up the current too fast from zero - or (unphysical) try to start from a nonzero coil current without first doing a stationary initialization. That is, you cannot start from initial conditions representing zero magnetic energy and go directly to a state with finite magnetic energy in zero time as that requires infinite input power (in the lab as well as in numerical modeling).
Given also the vastly different thermal and electric time scales, I would go for a frequency-transient approach like in the attached example and introduce the magnetic losses by using the Magnetic losses constitutive relation with mur'(|B|,T) and mur''(|B|,T) implemented as lookup tables/interpolation functions. The attached example uses functions to define the apparent mur (B/H) as a function of B and T and neglects the hysteresis losses.
-------------------Magnus
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Dear expert, hello! Thank you for your reply. I have been continuously implementing the solution you provided recently. At present, there is still a certain deviation between the simulation results and the actual situation. The main difficulty lies in the fact that the material properties for induction heating are still difficult to simulate accurately. The current material used is soft magnetic material. When using the parallel wire heating method, the induced magnetic field excited in the material is insufficient in strength and has a large distribution deviation, which shows a significant difference from the actual situation. Therefore, I prefer to introduce the calculation of hysteresis effect, which may make the simulation results closer to the actual application scenarios.