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Selecting internal boundaries as heat flux

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In my model, there is a photoacoustic dye in a tube which is within a water tank. The dye is excited by a pulsed laser due to which the temperature of the dye rises. Then, the laser is switched off. Eventually, the heat dissipates from the dye to the surrounding water. [Fig. 1]

I am trying to plot the rate of heat dissipation or temperature drop over time.

My problem is I am not able to select the boundary of the tube as the heat flux [Fig. 2] for the laser. It is showing as not applicable [Fig. 3]. It seems for heat flux only the external boundaries of the geometry can be selected.

Is there a way I can select this boundary using conditinal geometry or by any other way?

Please suggest what should I do?



1 Reply Last Post 6 mars 2018, 23:39 UTC−5

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Posted: 6 years ago 6 mars 2018, 23:39 UTC−5
Updated: 6 years ago 6 mars 2018, 23:41 UTC−5

Replying my own question in case it helps others.

Got my help from Comsol tech support.

"The heat flux can only be use for external boundaries. The heat flux through internal boundaries can be automatically computed. If you want to add heat flux on internal boundary you can use boundary heat source node."

It worked for me.

Replying my own question in case it helps others. Got my help from Comsol tech support. "The heat flux can only be use for external boundaries. The heat flux through internal boundaries can be automatically computed. If you want to add heat flux on internal boundary you can use boundary heat source node." It worked for me.

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