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How to induce temperature-dependent variable in HTS cable model
Posted 28.07.2012, 10:34 GMT-4 Heat Transfer & Phase Change Version 4.2 1 Reply
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I am new to COMSOL, and i am trying to model of ac losses in HTS cable. Firstly, i have already implemented T-independent model, which assumes Jc and alpha as constant. In this assumption, the comsol can work well. However, now i need to consider the effects of temperature on Jc and alpha. I simply change the Jc and alpha from parameters to variables. It encountered a problem:
Feature:Time-Dependent Solver1(sol1/t1)
Error: Failed to evaluate expression.
Checking the Error, it said
Attempt to evaluate real logarithm of negative number.
- Function: log
Failed to evaluate temporary symbolic derivative variable.
However, i have clearly defined these variables in Model1. Hope someone can help me.
Feature:Time-Dependent Solver1(sol1/t1)
Error: Failed to evaluate expression.
Checking the Error, it said
Attempt to evaluate real logarithm of negative number.
- Function: log
Failed to evaluate temporary symbolic derivative variable.
However, i have clearly defined these variables in Model1. Hope someone can help me.
1 Reply Last Post 06.08.2012, 09:53 GMT-4
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Posted:
1 decade ago
Hallo Anlong,
it tells you that it tries to compute the log from a negative nuimber. Look where you use
log and make sure its argument never becomes negative.
Jens
it tells you that it tries to compute the log from a negative nuimber. Look where you use
log and make sure its argument never becomes negative.
Jens