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Step function that switches at derivative value

Posted 31.08.2022, 20:21 GMT-4 Modeling Tools & Definitions 1 Reply

Jessica Hoffman
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Hi,

I am trying to define a step function for a parameter that changes when the time derivative of a variable changes (rather than at time = 0 or the usual use of step function). It only changes for one domain of the geometry. All other regions have a constant value of the parameter, e.

Here is the step function for the region:

e = { 0.06 if Vm' >= 0; 0.3 if Vm' <0}

So it will act like an On/Off switch basically as the value of Vm changes with the course of time.

1 Reply Last Post 13.09.2022, 19:36 GMT-4
Temesgen Kindo
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Posted: 2 years ago 13.09.2022, 19:36 GMT-4

First define a step function that changes from 0.3 to 0.06 at 0. Let's say the name was Step1.

Then use Step1(Vm').

First define a step function that changes from 0.3 to 0.06 at 0. Let's say the name was Step1. Then use Step1(Vm').

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