Transient Heat Transfer model with Uniform Heat source and Global Shutter Setting


#1

Hello,

I have a question about using the global source shutter option in a transient heat analysis with a uniform heat source. Could you please help figure out what is the issue here. Please see the DEVICE file fromt he gdrive link below.

Heat Transfer Transient

I have specified a TiW heater (in contact with Air, sitting on SiO2 layer) as the heat source, and applied uniform heat source to the volume of TiW.

I am now trying to use the global source shutter to turn on/off the heat source and analyze the transient response of heat transfer.

However, from the T plot, it seems the heat source is not observing the shutter correctly, the Tempreature profile at time 0 ~ 1.5us is the same result as the steady state result, as if the shutter has been on all the time. And the T response does not make sense as t increases.

I 'd appreciate any input to help understand the global shutter function.

Thanks.


#2

Hi @guangcan, I think the problem here is the value of toff in your global shutter. It is currently set to zero. However, since you have selected “pulse on”, toff should be larger than ton. If you simply want to turn the heat on at a certain time and do not care about toff then use the “step on” option instead.

A second thing to note is that in your setting of the shutter, you have ton at 1.5e9 fs and a tslew of 1e10 fs. That means your pulse will turn on at 1.15e10 fs. However, in your boundary condition, you have defined the transient boundary up to 1e10 fs. This means the simulation will only run up to the maximum time it sees (which is in the shutter = 1.15e10). You will therefore not be able to see the response of the system to the pulse for which you will have to run the simulation much longer. In the attached file I have made the final time in the boundary condition 5e10 fs so that you can see the transient response of the system to the pulse properly.

2D_transient_MOD.ldev (6.1 MB)