[HassanGill]

Hi, I am new to CFD simulations. The species that I want to transport circles around the inlet and doesn't move towards the outlet. Attached, please find my configuration file and inlet.dat file.

config.txt

inlet_m.txt

Any help or suggestion is highly appreciated.

[bigfootedrockmidget]

It's a bit hard to say without the mesh to reproduce the issue, but you could first try to run it :
1. steady
2. with uniform boundary conditions instead of a profile


When in doubt, start from something that works, either a tutorial or one of the regression tests in Testcases/ and build up your case step by step.

[cristopher_morales]

Originally Posted by HassanGill

Hi, I am new to CFD simulations. The species that I want to transport circles around the inlet and doesn't move towards the outlet. Attached, please find my configuration file and inlet.dat file.

Attachment 96820

Attachment 96821

Any help or suggestion is highly appreciated.

Hi Hassan,

Are you simulating air or other gas? given your setup, it seems that you are simulating air, so if that is the case, you should check your value of the diffusivity
KIND_SCALAR_MODEL= SPECIES_TRANSPORT
DIFFUSIVITY_MODEL= CONSTANT_DIFFUSIVITY
DIFFUSIVITY_CONSTANT= 1

1 looks quite high, the diffusivity constant should be a value around 1.8*10^-5 , so now you are using a huge value, that might explain why the species does not move towards the outlet, because the diffusivity term is too high. Also as an advice, it is recomended to set the SPECIES_INIT equal to the species mass fraction that you provide in the first inlet (0.5 if I am not mistaken) because that improves the convergence.
SPECIES_INIT= 0.5
SPECIES_CLIPPING= YES
SPECIES_CLIPPING_MIN= 0.2
SPECIES_CLIPPING_MAX= 1.0

Additionally, you can try the option BOUNDED_SCALAR instead of the SCALAR_UPWIND.

Finally, the
MARKER_INLET= (inlet, 300, 1.0, 10.0, 10.0, 0.0)

(10,10,0.0) should be the normal direction of the velocity, the second value 1.0 is the magnitude of the velocity, so if your velocity is 10 m/s, you should write the marker_inlet as follows:
MARKER_INLET= (inlet, 300, 10.0, 1.0, 1.0, 0.0)
and the INC_VELOCITY_INIT= ( 10.00, 0.0, 0.0 )

Best regards,

Cristopher Morales Ubal