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Step function. Spherical 1D Cell Model

Posted Oct 15, 2011, 1:10 p.m. EDT Version 3.5a 1 Reply

Gerardo Felix
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Hi everyone...

I'm modeling a spherical cell with time dependent varying conditions. I want to vary the concentration of the boundary condition using the heaviside function (flc1hs or flc2hs) to simulate a voltage pulse. When i solve the model i get the error message: "Last time step is not converged". The error ocurrs at the time step at which the step function changes its value (from 0 to some value). I've also tried to define a function from a file that contains the step data (same problem when tried to solve the model).

When i set a constant concentration at the boundary condition, the model solves without a problem. So the convergence problem is related to the step function...

What can i do to solve this???

Please help me...
1 Reply Last Post Oct 17, 2011, 6:04 a.m. EDT
Lasse Murtomäki
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Posted: 1 decade ago Oct 17, 2011, 6:04 a.m. EDT
I have used step function in a similar way (potential steps) without any problems. What are your equations, i.e. physics?

I have used step function in a similar way (potential steps) without any problems. What are your equations, i.e. physics?

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