[gbettega]

Hello,
a couple of very short questions.

1) First question:

Incompressible flow simulation:
A fluid with density 4.1 [kg/m^3] viscosity 2x10^-4 [Pa s] enters a straight pipe having D = 2.7 [m] diameter, with velocity V = 0.4 [m s^-1]: see picture (mesh of one half of the domain). So Re ~ 2.0 x 10^4

Su2 tells me

+------------------------------------------------------------------------------+
| Mach Number| -| -| -| 0.000539562|
| Reynolds Number| -| -| -| 2067|
+------------------------------------------------------------------------------+

2) second question:

Also the Ma is shown: how this "default" value is computed?
Does it comes from the .cfg setting?

[...]
% Bulk Modulus for computing the Mach number
BULK_MODULUS= 1.42E5


Does it share something with the artificial compressibility method in
"Simulation and Adjoint-based Design for Variable Density Incompressible Flows with Heat Transfer" [T.D. Economon] and references therein?

Thank you very much, in advance
Giovanni

[cristopher_morales]

Originally Posted by gbettega

Hello,
a couple of very short questions.

1) First question:

Incompressible flow simulation:
A fluid with density 4.1 [kg/m^3] viscosity 2x10^-4 [Pa s] enters a straight pipe having D = 2.7 [m] diameter, with velocity V = 0.4 [m s^-1]: see picture (mesh of one half of the domain). So Re ~ 2.0 x 10^4

Su2 tells me

+------------------------------------------------------------------------------+
| Mach Number| -| -| -| 0.000539562|
| Reynolds Number| -| -| -| 2067|
+------------------------------------------------------------------------------+

2) second question:

Also the Ma is shown: how this "default" value is computed?
Does it comes from the .cfg setting?

[...]
% Bulk Modulus for computing the Mach number
BULK_MODULUS= 1.42E5


Does it share something with the artificial compressibility method in
"Simulation and Adjoint-based Design for Variable Density Incompressible Flows with Heat Transfer" [T.D. Economon] and references therein?

Thank you very much, in advance
Giovanni

Dear Giovanni,



Regarding the first question, SU2 computes the Reynolds number assuming REYNOLDS_LENGTH=1.0

you can change that option. Also the options INC_DENSITY_INIT is used for computing the Reynolds number. So the Reynold number is computed based on the free_stream_values which for the incompressible solver are the values provided in the config options that start with INC_......
I think the same applies to your second question.
The incompressible solver and preconditioning implemented in SU2 are the ones depicted in the paper that you mentioned.
I hope this might help to you.


Best regards,


Cristopher Morales Ubal