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ODE equation : how to manage a variable that is physicaly bounded
Posted 09.10.2015, 04:58 GMT-4 Parameters, Variables, & Functions, Studies & Solvers 0 Replies
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Here is my question.
My model implement an ODE equation on a temporal simulation.
The ophysical variable is named u :
The equation : ea*utt + da*ut =f
In my actual case, ea = 0 and da =1
As a consequence the equation becomes the very simple one : ut = f
The function f is quite complexe, depends on various variable, and its value can be very high sometimes.
The variable u corresponds to a dimensionless variable. Whatever happens, its value is always between 0 and 1.
The problem I have is the following :
The timestep of my temporal simulation is automatic and change depending on the instantaneous state.
Due to the fact that that f can has a large value and that the timestep is variable, sometimes, the ODE equation resolution induce very high value for the variable u -> u is then outside of the field [0,1] I specified before.
This is physicaly not acceptable.
How can I improve my model ?
Best regards.
Hello Didier Buzon
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