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Posted:
1 decade ago
25.04.2010, 14:11 GMT-4
You can have different release times using logical expressions like this:
U_in*(t==0)+U_in_2*(t==1000)
it may not work as your steps may not pass the exact time, so you may use intervals like
U_in*(t<1e-6)+U_in_2*(t>100)*(t<101)
hope this is what you're looking for.
You can have different release times using logical expressions like this:
U_in*(t==0)+U_in_2*(t==1000)
it may not work as your steps may not pass the exact time, so you may use intervals like
U_in*(t100)*(t
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Posted:
1 decade ago
25.04.2010, 14:57 GMT-4
Hi Daniel,
I am really sorry but I didn't follow what you explained. Do i put these conditions in the initial value columns for the sub domain settings? If so, how can I put a time dependent equation in the initial condition space? Its assuming everything to be at t=0 in that box.
Thanks in advance.
Hi Daniel,
I am really sorry but I didn't follow what you explained. Do i put these conditions in the initial value columns for the sub domain settings? If so, how can I put a time dependent equation in the initial condition space? Its assuming everything to be at t=0 in that box.
Thanks in advance.
Ivar KJELBERG
COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted:
1 decade ago
26.04.2010, 14:49 GMT-4
Hi
I agree too that in the initial value (t0=0 mostly) there is no reason to put time conditional equations, but from your description I too understand you were in a transient analysis and driving your volatage by a time function of the type Danial is proposing but I would not put it in the initial condition but in the main variable definition
Have fun Comsoling
Ivar
Hi
I agree too that in the initial value (t0=0 mostly) there is no reason to put time conditional equations, but from your description I too understand you were in a transient analysis and driving your volatage by a time function of the type Danial is proposing but I would not put it in the initial condition but in the main variable definition
Have fun Comsoling
Ivar
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Posted:
1 decade ago
27.04.2010, 00:26 GMT-4
Hey Ivar,
How can I define the equation for my variable? There is no such provision in the 1D PDE mode. I tried used a tanh function in the intial time box...but that doesnt seem to make any difference at all. How do I set the time for a second diffusion wave release? Here is what I entered in the u(t0) column in the 'init' section of coefficient form PDE:
u(t0)=A*exp((-(x-x0)^2)/M)*(tanh(10*(t-6000))+1)/2
the part from A to M is my initial condition. and 6000 is the time at which I want release a second wave with the same i.c as at t=0.
Thanks in advance.
Hey Ivar,
How can I define the equation for my variable? There is no such provision in the 1D PDE mode. I tried used a tanh function in the intial time box...but that doesnt seem to make any difference at all. How do I set the time for a second diffusion wave release? Here is what I entered in the u(t0) column in the 'init' section of coefficient form PDE:
u(t0)=A*exp((-(x-x0)^2)/M)*(tanh(10*(t-6000))+1)/2
the part from A to M is my initial condition. and 6000 is the time at which I want release a second wave with the same i.c as at t=0.
Thanks in advance.
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Posted:
1 decade ago
05.10.2011, 08:51 GMT-4
I guess that the solution could be to change the source term F..
I guess that the solution could be to change the source term F..