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Induction heating
Posted 04.05.2013, 06:11 GMT-4 Electromagnetic Heating, Heat Transfer & Phase Change Version 4.3 6 Replies
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I'm getting some trouble about induction heating using frequency-transient solver.
In the 2D-axisymmetric model, I have an aluminium workpiece surrounded by 12 turn of coil (each one setted in "single turn coil domain 1").
In the "single turn coil domain 1" I set the power of the coil, and here is the problem! If i set very low power (10-60 W) the simulation works so good, but if I set the power I need (at least 6000 W) I get the error
"Time-Dependent Solver 1 (sol1/t1)
Failed to find consistent initial values"
I think I have to change some BC, but i don't know which one!
Anyone knows?
Thank you!
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perhaps it's simply that your initial conditions are too far from the solution so jumping straight to 6kA is too stiff, have you tried to use a step function and let COMSOL ramp up the current from nearly 0 to your max value with a smmoth step or ramp ?, in 3-10 steps ?
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Good luck
Ivar
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So, the problem might be about to coil, passing from 0 W to 6000 W in a smallest time step?
PS: why you talked about current and not power?
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just a glimps, I usually increase current in coils, but you are right it can also be power ;) Whatever drives your model. Do not forget that mesh, time steps and gradients are often linked by some fundamental formulas, so too steep gradients with finite mesh gives sometimes issues for the solver convergence. For that the parametric sweep are useful to help convergence, and to follow what is happening (use the plot while solving ...)
--
Good luck
Ivar
Please login with a confirmed email address before reporting spam
just a glimps, I usually increase current in coils, but you are right it can also be power ;) Whatever drives your model. Do not forget that mesh, time steps and gradients are often linked by some fundamental formulas, so too steep gradients with finite mesh gives sometimes issues for the solver convergence. For that the parametric sweep are useful to help convergence, and to follow what is happening (use the plot while solving ...)
--
Good luck
Ivar
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I read that setting power as input induces nonlinear equations, so could be better to set current.
But i would set both voltage and current, because if i set just one of them i don't know which value has the other one.
How i can do it? If i set current, there is a setting that allow me to set voltage too?
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