Problem with assign Scalar (Local mean age of Air)

[Anonymous]

Hi,

I'm struggling with how to assign scalar. I'm doing a simulation of an urban wind flow.

Questions

1. Can anyone tell me how to assign scalar to a model, I try a many time but it's doesn't show any result so far.

    I would like to know time and speed that air travel through the area (Local mean age of air).

2. I also apply temperature to every side but also no results.

Materials

01 Air

02 Concrete

Boundary conditions

Front : Velocity 5 m/s

           Scalar (Steady state : 1)

Side : Slip/Symmetry

Back : Pressure : 0

Top : Velocity X 5m/s

Temperature 30c

Diffusion Coefficient Carbon Dioxide
0.16 cm²/s

The results i got

This is something that i expect for i results.

Thank you so much.

Sorry for my english.

[Jon.Wilde]

I suggest you simplify this a little, have flow, temp and scalar at the inlet and P=0 at the outlet. 

To me it looks like you could remove side wall boundary conditions.

Where is the other scalar value assigned? If you have 1 assigned somewhere, where is the 0?

You really also need a larger domain, a much longer outlet, to be sure the flow is nice and laminar again before it exits.

Hope that helps,

Jon