How to input a time-varying (sinusoidal) heat rate?

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Hi all,

I am using the Heat Transfer and Laminar Flow modules within Comsol for a time dependent simulation. For my initial model I added a heat source by specifying a constant value for the heat rate -which is essentially a step function starting at time = 0. I am trying to adjust this now so the heat rate is time-varying and specified by a sinusoidal function. I found this previous thread which says I can replace the constant value with something like 'Asin(Bt)+C'. However, when I do this I get the error message / warning: "unexpected unit of input". Does anyone know what I am doing wrong? Does COMSOL have a built in variable that you can use to specify time?

Thank you


2 Replies Last Post Jan 12, 2021, 3:17 PM EST
Jeff Hiller COMSOL Employee

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Posted: 2 weeks ago Jan 12, 2021, 3:04 PM EST

Hello Vivek,

Mathematical functions like sin expect a scalar input, so check if your B has dimensions of 1/time. That's likely your problem.

Best,

Jeff

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Jeff Hiller
Hello Vivek, Mathematical functions like sin expect a scalar input, so check if your B has dimensions of 1/time. That's likely your problem. Best, Jeff

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Posted: 2 weeks ago Jan 12, 2021, 3:17 PM EST

Hello Vivek,

Mathematical functions like sin expect a scalar input, so check if your B has dimensions of 1/time. That's likely your problem.

Best,

Jeff

Thanks! This solved the issue.

>Hello Vivek, > >Mathematical functions like sin expect a scalar input, so check if your B has dimensions of 1/time. That's likely your problem. > >Best, > >Jeff Thanks! This solved the issue.

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