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How to define perturbation in initial conditions?

Posted Dec 8, 2017, 11:39 a.m. EST 3 Replies

Harry Jenis
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Hi, I'm remodeling a paper, and I need to define a perturbation in my initial conditions to validate my model with the results in paper. Paper has calculated the stationary form of the equation and then added a 1% perturbation in the sationary results and put the result in the initial condition for the time dependent model, I need to know how I can do this? Exact sentence of the paper: "The initial condition for the transient calculations is generated by applying a locally 1% random perturbation to the anion and cation concentration fields obtained from the steady calculation."

3 Replies Last Post Mar 29, 2018, 8:44 a.m. EDT
Vasily Kozhevnikov
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Posted: 7 years ago Dec 9, 2017, 2:04 p.m. EST

Dear Harry,

I recommend you to create two studies for the same model. The first will be the stationary one, and the second will be time-dependent with the initial conditions from the first. Simply define ICs in the second study by using 'withsol' operator and add the perturbation to it.

Dear Harry, I recommend you to create two studies for the same model. The first will be the stationary one, and the second will be time-dependent with the initial conditions from the first. Simply define ICs in the second study by using 'withsol' operator and add the perturbation to it.
Neta Leibowitz
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Posted: 7 years ago Mar 7, 2018, 9:39 a.m. EST

Hi, I have the same problem. How to I add the perturbation? The initial condition allows me to choose only from one of the solutions. Thank you

Hi, I have the same problem. How to I add the perturbation? The initial condition allows me to choose only from one of the solutions. Thank you
Harry Jenis
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Posted: 7 years ago Mar 29, 2018, 8:44 a.m. EDT

Dear Harry,

I recommend you to create two studies for the same model. The first will be the stationary one, and the second will be time-dependent with the initial conditions from the first. Simply define ICs in the second study by using 'withsol' operator and add the perturbation to it.

Hello Dear Vasily I don't know how to use the so called 'withsol' operator, would you please give me an example? or any instruction on how to use it in IC?

>Dear Harry, > >I recommend you to create two studies for the same model. The first will be the stationary one, and the second will be time-dependent with the initial conditions from the first. Simply define ICs in the second study by using 'withsol' operator and add the perturbation to it. Hello Dear Vasily I don't know how to use the so called 'withsol' operator, would you please give me an example? or any instruction on how to use it in IC?

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