I'm trying to do some basic flow simulations. For this simulation I want to measure the rise of temperature inside this box. I've drawn a small box and In the middle I've put a little box. On one side of this little box 45 Watts will be generated as heat source. The temperature outside of the box will be somewhere in between 25 or 45 degrees Celsius.
Can anybody help me with how I measure the rise of temperature inside a box. And what the effect of this little box will be.