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Time dependent study crashes at missing thermal resistance parameter

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Hey guys,

i encountered a weird problem regarding a time dependent study solving heat transfer in terms of thermal resistance intersections. First of all, im working with Comsol 5.3a and a stationary solver succeeds the problem. However, applying time dependent heat transfer values by unchanged thermal resistance values, the solver crashes telling me the variable "comp1.ht.tl1.ds" is undefined. After a short investigation, i found out that this variable is supposed to declare the layer thickness of the applied thermal resistance surface. My question now is, why comsol tries to find such a value for time dependent studies whily stationary solver do not AND why the module does not provide any possibility to enter a layer thickness. How am i supposed to provide variables when comsol does not even demand them? I can only enter the resistance value and no layer thickness .....

Even though, i found a workaround declaring the missing layer thickness as an global variable and setting the thickness to very small values. Might this cause any problems concerning solver accuracy ?

Best Regards, Max


0 Replies Last Post 01.04.2019, 08:31 GMT-4
COMSOL Moderator

Hello Maximilian Stiegler

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