[Axel1]

Dear all,

I am studying the mixing properties inside a tank both experimentally and numerically.

I already realized a steady 3D simulation of the water flow inside the tank. Simulation and experiments are in good agreement.
I also realized experimentally a continuous injection of dye and would like to reproduce this using simulation BUT by using transient solver to get time-dependant informations concerning mixing.

I already tried to use UDS for the dye which have same physical properties as water. As a result, the UDS seems to only diffuse from the inlet and is not convected by the flow. See Attachements at 1s, 100s and 200s.
Here is my procedure step-by-step:
1) I defined a UDS with Flux Function on "mass flow rate"
2) I switched to "Transient" solver
3) In BC, I enter a Specified Value of UDS = 1 at the Inlet and a 0 Flux value on other boundaries.
4) In Controls panel, I unchecked Flow and Turbulence equations to only solve transport equations of my UDS and to keep the flow solution obtained from steady solution.
5) I did NOT initialize and i ran calculations with time-step size = 0.1s.

So my questions are :
- Is it possible to use a steady flow solution and then use this solution to solve time-dependant UDS transport ? I feel like it should be douable but i am probably missing something.
- I think that other methods as Species transport or DPM are also usable in my case ? What would you recommend between those 3 ? (I am afraid that Species Transport and DPM migth require high computation time)

Thank you so much in advance.

[Far]

Did you get solution to problem?