About species transport module in fluent
 

I am new to the species transport module in fluent and try to model a simple 3D street canyon case with two long rectangular blocks with a street canyon in between. I set a line source with the mass flow inlet boundary condition and set species mass fraction as 1 with say average mass flux of 5kg/m^2s. The only species is assumed to be NO. An velocity inlet and outflow boundary is set as the inflow and outflow and the builing blocks as wall and other side and top faces of the computational domain as symettry. I am modelling without any species reaction, so i turned off volumetric reactions and remain any other things as default in the species module. I used the Rke turbulence model and a standard log wind profile and standard tke and dissipation rate profile at the inlet. However, i get some strange results with very large mass flow rates obtained at the side and top of the street canyon. Also i tried to do a canyon of Height/street canyon width of 4:1 and 6:1 and calculate the total canyon pollution concetration and get a greater value for the 4:1 case which is strange. I am wondering if i have something wrong in the settings or i am missing sth. Thanks for the help!!!

Hi,
I am wondering if you have solved your problem.
I am modelling a street canyon too but with reacting flow. I set species line source by specifying the source terms in the fluid zone but I not sure if it is the correct way to do it. Could you give me some suggestions, please? Thank you.

3D street canyon simulation
 

Hello,
i am a new user to Fluent. i am working on pollutant dispersion simulation for a 3D street canyon.
Can anyone guide me regarding how to create the Geometry and the boundary conditions.

Thanx in advance,
prashnat