[zephyrus17]

I'm doing a Steady State age of air validation case where air @ 25C enters a simple room through a square inlet and exits from an exit across the room. The air enters at 1.68m/s and the outlet is just a 0 Pa outlet. I'm monitoring the age of air and also monitoring the turbulence kinetic energy (is this the most suitable?) to judge convergence. I'm following the journal and using the standard k-e turbulence model with 14% turbulence intensity.

Here is the journal article for it: http://www.inive.org/members_area/me...%5CUFSC492.pdf

The coarse mesh would converge with no problems, however the fine mesh would not. The advection time is around 17 seconds. I tried setting the local timestep to 5, at first; tried playing with the physical timestep, varying from 200 down to 0.17 seconds. No matter what I did, the converge would drop swifty to 1e-3, then just bounce around there. The lowest I got it down to was around 8e-4.

There was nothing wrong with the mesh itself as it showed no issues in the solver .out file.

Any suggestions on what to do next or what I'm doing wrong?