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mahdidelfan June 24, 2014 02:41

cfd solver
 
5 Attachment(s)
hi
my domain is a quarter of the original geometry of supersonic wind tunnel.wind tunnel mach number is 1.8 . in my domain Using tow symmetry boundary conditions and tow wall boundary condition and a boundary condition input and an output boundary condition my simulation cfx Boundary conditions is:
ANALYSIS TYPE:
Option = Steady State
TURBULENCE MODEL:
Option = k epsilon
BOUNDARY: inlet
FLOW REGIME:
Option = Subsonic
END
HEAT TRANSFER:
Option = Static Temperature
Static Temperature = 300 [K]
END
MASS AND MOMENTUM:
Option = Total Pressure
Relative Pressure = 1.8 [bar]
TURBULENCE:
Option = Medium Intensity and Eddy Viscosity Ratio
END
BOUNDARY: outlet
Boundary Type = OPENING
Location = outlet
FLOW REGIME:
Option = Subsonic
END
HEAT TRANSFER:
Opening Temperature = 300 [K]
Option = Opening Temperature
END
MASS AND MOMENTUM:
Option = Opening Pressure and Direction
Relative Pressure = 84000 [Pa]
END
TURBULENCE:
Option = Medium Intensity and Eddy Viscosity Ratio
END


wall
HEAT TRANSFER:
Option = Adiabatic
END
MASS AND MOMENTUM:
Option = No Slip Wall
END
WALL ROUGHNESS:
Option = Smooth Wall
END

After 1600 itration cfx solver stop solution .
The error is in the attached image:
Please Help me, please
Thanks for all

Martin_Sz June 24, 2014 03:26

Try to define inner type of outlet
you can make mass flow on inlet and outlet (if you know values of these BC).
The next step is to increase memory allocation in solver (default 1). You can increase to 3.

Martin_Sz June 24, 2014 03:27

Or so You can change to static pressure on outlet

mahdidelfan June 24, 2014 03:43

hi
Martin
Thanks for the answer
I do not know the mass flow inlet and outlet. But by placing the static pressure at the outlet boundary conditions arise during Solve backflow
Why is this form of residuals?
And why the solution is stopped?

mahdidelfan June 24, 2014 03:45

I am using the quick processing center. Many computing cores is 28 digit

mahdidelfan June 24, 2014 03:49

Quote:

Originally Posted by Martin_Sz (Post 498376)
Try to define inner type of outlet
you can make mass flow on inlet and outlet (if you know values of these BC).
The next step is to increase memory allocation in solver (default 1). You can increase to 3.

What do you mean?
Try to define inner type of outlet

Martin_Sz June 24, 2014 05:23

Inner like mass flow, static pressure etc.

Martin_Sz June 24, 2014 05:27

your solution is stopped because You have high velocity on inlet - and that makes high pressure on domain. So on the outlet you have overflow.
You can also change solver model (turbulence) to SST.

mahdidelfan June 24, 2014 12:13

Quote:

Originally Posted by Martin_Sz (Post 498408)
your solution is stopped because You have high velocity on inlet - and that makes high pressure on domain. So on the outlet you have overflow.
You can also change solver model (turbulence) to SST.

by solver model (turbulence) to SST i can not capture normal shock in the duct.in the inlet velocity is ~=68 m/s


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