Learning Forum

[David.Austin]

I am trying to simulate cooling of material contained in a sagger (box) as it traverses through the cooling conveyor of a kiln where air is blown over it. This is a continuous process where for each sagger ejected from the system after cooling another enters at the start. We are interested in understanding the thermal gradient within the solid after cooling. Cooling durations within the conveyor are on the order of hours.

My question:

Is it possible to transform this from a transient problem to an equivalent steady state problem through the use of moving reference frames? 

(effectively the frozon rotor problem but where we are translating linearly instead of rotating about an axis)

 

Illustration of the problem below:

 

We have tried a number of setups where the moving frame is applied to the solid, solid and fluid, etc. and in some cases get solutions that seem reasonable at first glance (ie - temerature is decreasing for saggers that have made it further down the traverse) however upon closer inspection it becomes apparent the first sagger (the one with the least residence time in cooling - just entered) has a temperature above the initial condition (900+ C instead of inital condition 700C)

[Federico]

Hi David, 
MRF is used for steady-state problems and hence it will not capture transient effects such as cooling of saggers entering the conveyor. MRF only introduces a source to account for the motion in the MRF.