Hey guys,
I am new to FEATool trying to evaluate its features before purchasing a commercial license. I tried to adapt the following test case to the best of my abilities from the Tutorial
"Resistive Heating in a Tungsten Filament"
I am trying to set up a model simulating the thermal behavior of a ceramic PTC heating element.
The basic model works, but I did not have success yet in respecting the temperature dependent behavior of the electrical resistance in PTC ceramics, which is highly un-linear around a certain temperature, the so called Curie-temperature.
Ideally this should be built through a table of measured values and interpolation, but for now I tried to work with logical expressions.
For the conductivity value in the "Conductivity Media DC" equation I tried to enter the following:
(T<473)*100 + (T>=473)*(T<475)*10 + (T>=475)*1
Expected behavior:
T<473K -> 100 S/m
T between 473K and 475K -> 10 S/m
T>475K -> 1 S7m
I also entered the entire expression in the source term "Q" of the "Heat Transfer" equation, but judging from the error I receive, I didn't even get that far.
"Could not evaluate the expression "(((aSubExpr(:,1)<473).*100)".
Please check and make sure that it is a valid expression."
test.fea
Locked
