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how to express a mathematical function presented in following form ?
Posted Jun 26, 2012, 11:58 a.m. EDT Studies & Solvers Version 4.2a 1 Reply
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Hi,
Can any body sort problems listed below
1. I need to implement an expresion in the following form in comsol multiphysics
zeta = T* ( Mf-Ms) for T(temperature) increasing
T*(As-Af) for T decreasing
2. do comsol support expressions like g= A*f(t) ;for f(t)-f(t-1)>0
B*f(t) ;for f(t)-f(t-1)<0
Exactly saying can we define functions f(t) and f(t-1) [time delay forms in comsol]
Krishna Chaitanya S
Can any body sort problems listed below
1. I need to implement an expresion in the following form in comsol multiphysics
zeta = T* ( Mf-Ms) for T(temperature) increasing
T*(As-Af) for T decreasing
2. do comsol support expressions like g= A*f(t) ;for f(t)-f(t-1)>0
B*f(t) ;for f(t)-f(t-1)<0
Exactly saying can we define functions f(t) and f(t-1) [time delay forms in comsol]
Krishna Chaitanya S
1 Reply Last Post Jun 26, 2012, 2:51 p.m. EDT
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Posted:
1 decade ago
Hi
if you are solving for T (dependent variable, you should have access to Tt the time derivative of T, hence you could look at the sign of Tt to learn if it is increasing or decrasing and use an "if(Tt>0, positive, negative)"
Check f you find a Tt in your equations for your physics case, or "just" try to plot Tt
--
Good luck
Ivar
if you are solving for T (dependent variable, you should have access to Tt the time derivative of T, hence you could look at the sign of Tt to learn if it is increasing or decrasing and use an "if(Tt>0, positive, negative)"
Check f you find a Tt in your equations for your physics case, or "just" try to plot Tt
--
Good luck
Ivar