CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   SOLUTION CONTROLS?? (http://www.cfd-online.com/Forums/fluent/39950-solution-controls.html)

naus March 3, 2006 14:11

SOLUTION CONTROLS??
 
please tell me how to put the right solution controls in

FLUENT??

Josh March 3, 2006 15:06

Re: SOLUTION CONTROLS??
 
They are automatically set to 0.001, you can change according to the convergence of the solution.

naus March 4, 2006 02:54

Re: SOLUTION CONTROLS??
 
I want to say,how to choose the disretization when I do solve-controls-solution:

pressure= standard or PRESTO!...??? pressure velocity coupling= simple or simplec...??? momentum=first order upwind or second order upwind...??? ... thanks a lot for your help


Rizwan March 4, 2006 08:07

Re: SOLUTION CONTROLS??
 
Go through chatper 24 of Fluent Help tutorial guide. Specifically speaking sections 24.6, 24.7 and 24.8.

Regards

naus March 4, 2006 14:05

Re: SOLUTION CONTROLS??
 
I read these sections but when I put these values:

1-uder relation factors pressure=0.3 density= 0.8 body force=1 momentum=0.7 turbulence dissipation rate 0.8 turbulence viscosity=0.8 h2o=0.8 energy=0.8

2-descritisation pressure=PRESTO! pressure velocity coupling = second order upwind density = second order upwind momentum= second order upwind turbulence kinetic energy= second order upwind turbulence dissipation rate= second order upwind h2o= second order upwind energy= second order upwind

and I open my file (the next time), I have this message :

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

Error: Set_Thread_Variables: wta(real) Error Object: ((constant . 0) (profile "" ""))

PLEASE HELP ME :( WHERE IS THE ERROR ??????????????

Rizwan March 5, 2006 02:36

Re: SOLUTION CONTROLS??
 
Can you explain what problem you are solving. As a general gudiance i can say that, choose first order before going to second order. and when you initialize the solution make sure that the paramemters for tubulent viscosity and dissipation are relavitely low of the order of about 1e-5.

regards

naus March 5, 2006 03:14

Re: SOLUTION CONTROLS??
 
I study a ventiled room , I have a natural convection.

I think that I was mistaken in gauge pressure too(in pressure outlet BC),I have put in operating pressure 101325pas and I put gauge pressure = 5pas, because my outlet pressure is 101330pas.

it is right wath I do????????????????????????????????

Rizwan March 6, 2006 02:36

Re: SOLUTION CONTROLS??
 
yes it is correct. if you have natural conveiton make sure that the domaain is much large so that the walls woudlnt affect the flow inside the domain. i personally have experience about such situation in natural convection.



All times are GMT -4. The time now is 12:19.