CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   CFX (https://www.cfd-online.com/Forums/cfx/)
-   -   A problem about using the Spalart Allmaras model (https://www.cfd-online.com/Forums/cfx/186564-problem-about-using-spalart-allmaras-model.html)

shiningkissss April 22, 2017 09:32

A problem about using the Spalart Allmaras model
 
Hello, every CFD expert:
I met a question when using the Spalart Allmaras turbulence model in CFX15.0. The CFX SOLVER reported an error as is described below:

" Error in subroutine CAL_VAR_ICS :
Specified ICTYPE : AUTO_VAR_TKI is not valid for Kinematic Eddy Viscosity at
domain GAS
GETVAR originally called by subroutine SU_DVAR_ZONE"

I checked my mesh, the y+ is sure lower than 1. I changed the wall function from Default to Scalable but this didn't make sense.

If this is because the Spalart Allmaras model is enabled in beta feature which is shown in CFX-pre or because I missed some settings that are particularly needed when using this model?

cfdgremlin April 23, 2017 07:19

It looks like an issue with the initial conditions. How are these specified?

shiningkissss April 23, 2017 22:03

Quote:

Originally Posted by cfdgremlin (Post 645957)
It looks like an issue with the initial conditions. How are these specified?

I couldn't insert image successfully (may due to the internet or the explorer).
I simulated an impingement cooling structure. The structure contains a coolant supply chamber and a target chamber. Totally 10 impingement holes are established to connect those two chambers. The coolant flow into the coolant supply chamber at the entrance and are injected through the impingement holes onto the target chanmber inside surface and flow out at the end of the target chamber.

boundary conditions:

inlet: subsonic; normal speed with 11.0m/s; 1% turbulent intensity and auto compute length; total temperature with 348.15K;

outlet: subsonic; static pressure 0.1mpa;

wall of the target surface: no slip wall; smooth wall; the wall are set with a
fixed temperature of 419.15K in order to simulate the heat transfer at the target surface;

wall of the others: no slip wall; smooth wall; adiabatic.

shiningkissss April 23, 2017 22:09

Quote:

Originally Posted by cfdgremlin (Post 645957)
It looks like an issue with the initial conditions. How are these specified?

And the initial conditions:
velocity type: cartesian;
cartesian velocity components: automatic;
static pressure: automatic;
temperature: automatic;
turbulence: low(intensity=1%)

shiningkissss April 23, 2017 22:28

Quote:

Originally Posted by cfdgremlin (Post 645957)
It looks like an issue with the initial conditions. How are these specified?

Sincerely thanks your advice.

The cfx-solver didn't announce errors any more when I change the initial turbulent intensity to 1% with a turbulent viscosity ratio 10.

Thank you for reminding me to change the initial conditions which I totally neglected before.


All times are GMT -4. The time now is 16:21.