Hi there,
The T1 passive scalar is set to 1 1/s if you go to the advanced tab. And because scalars are independent regarding unit, they can be interpreted in the way we define them, according to SimScale Documentation | Online Simulation Software | SimScale
In this case the project poster calculated a uniform distrbution of the CO of 2.77e-8 kg/(m^3 *s), hence we simply multiply the T1 result with this value and divide by the air mass in 1m^3, and finally multiply with 1000000, to get a mg/kg corresponding with ppm. I loaded the simulation results into paraview and entered “(T1 * 2.77E-08)/(1.2041) *1000000” in the calculator. This is the result for the case with the fans:
Below you can see where you find where the flux is defined
Hope that answers some of your questions. Regarding the exhaust flow, I think that it is some sort of system, that has some flow rate capability and hence the poster chose that as a boundary condition. However, you could pick any value and see how that helps the overall CO distribution. Which makes this a really cool simulation I think. That’s why I also went ahead and tried to answer your question, because otherwise I would not have seen this project.
Kind regards,
Tolga