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Time-dependent heat flux [Neumann boundary condition]

Posted 5 nov 2019, 06:52 GMT-5 Heat Transfer & Phase Change Version 4.3 2 Replies

Denis Kochan
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Hi guys,

I am new in COMSOL, and the same question I am posting, had already circulated several times. Unfortunately, I am not able to solve my problem with the "help" of those posted answers.

  1. I would like to solve time-dependent heat transfer problem in 2d
  2. On some boundaries there (see figure) are prescribed time-dependent incoming heat fluxes, in the form of goniometric functions: , where and are parameters I would like to vary later.
  3. In the module heat transfer in solids, I took "heat flux", out of three possibilities there, I don't know which I should chose, and how to implement my heat flux boundary conditions, say for is 1000 W/m and 20 Hz.

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2 Replies Last Post 5 nov 2019, 08:59 GMT-5
Edgar J. Kaiser Certified Consultant
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Posted: 5 years ago 5 nov 2019, 07:40 GMT-5
Updated: 5 years ago 5 nov 2019, 08:14 GMT-5

Denis,

if I understand properly this should be quite simple. The expression in the q0 field would look like: q0*cos(omega*t)^2

Define q0 and omega as global parameters or directly insert the values. Make sure that the time stepping properly resolves the function.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Denis, if I understand properly this should be quite simple. The expression in the q0 field would look like: q0\*cos(omega\*t)^2 Define q0 and omega as global parameters or directly insert the values. Make sure that the time stepping properly resolves the function. Cheers Edgar
Denis Kochan
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Posted: 5 years ago 5 nov 2019, 08:59 GMT-5
Updated: 5 years ago 5 nov 2019, 09:00 GMT-5

Thanks Edgar, it works now ... :)

Cheers,

D.

PS: the time step was inappropriate

Thanks Edgar, it works now ... :) Cheers, D. PS: the time step was inappropriate

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