# Why changing the simulation time in thermal simulation, does not change the result that much?

Hello,

I did the simulation of a lead in plane wave exactly like the tutorial "3.3.4 Heating from a standard active implantable medical device", when I change the simulation time in thermal simulation from 3600 s to 36000 s, the max temperature changes from 22.0035 to 22.0049. I would have expected higher value. I'm wondering what's the reason the temperature does not increase that much and is almost the same as before?

Thanks.

I'm wondering what's the reason the temperature does not increase that much and is almost the same as before?

The reason is probably simple physics: I imagine the EM field is not depositing a lot of power, so the temperature does not rise very much. In addition, there is a "cooling" effect from the 22C Dirichlet boundary condition. It is a bit like heating a large room with a small candle while the window is open...

Note that you can use the Stationary Thermal solver to compute what the steady state is.

Thanks. The max value of the color scale in the stationary thermal solver is about 10 times higher than transient thermal solver. What should I change in the transient simulation to get the temperature value the same as stationary thermal solver?

The steady-state of the temperature equation, if it exists, is the temperature field when time goes to infinity. I don't understand what you are trying to achieve here, but setting the simulation time to a much larger value should give you the same solution as the stationary solver.

Actually the temperature rise is very lower than what is measured in the lab and I'm wondering what is the reason.

I extract the max temperature at a point using a line passing through the point (I find lines of the intersection of the 3 slices xy-xz-yz at max). But the value is much smaller than the value which a point sensor gives and also the max value which the color scale bar shows. What is the reason?