| sErik |
January 25, 2010 07:41 |
Hi Foamers,
I still have trouble with my simulation. bounding epsilon is exploding and huge right from the start!
It's about a pipe flow with a starting pressure of 7638Pa and a inlet velocity of 1.7448 m/s. I'm interessted in the drop of pressure an the end of the curved pipe.
Quote:
...
Create time
Create mesh for time = 0
Reading field p
Reading field U
Reading/calculating face flux field phi
Selecting incompressible transport model Newtonian
Selecting RAS turbulence model kEpsilon
kEpsilonCoeffs
{
Cmu 0.09;
C1 1.44;
C2 1.92;
sigmaEps 1.3;
}
Starting time loop
Time = 0.001
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.0959227, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0562844, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.095863, No Iterations 1
GAMG: Solving for p, Initial residual = 1, Final residual = 0.00703477, No Iterations 4
GAMG: Solving for p, Initial residual = 0.23568, Final residual = 0.00179757, No Iterations 3
time step continuity errors : sum local = 0.00216907, global = -0.000147145, cumulative = -0.000147145
DILUPBiCG: Solving for epsilon, Initial residual = 0.994795, Final residual = 0.0275726, No Iterations 2
bounding epsilon, min: -82.1271 max: 5.59944e+06 average: 495.63
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 0.000932489, No Iterations 1
ExecutionTime = 13 s ClockTime = 26 s
Time = 0.002
DILUPBiCG: Solving for Ux, Initial residual = 0.553916, Final residual = 0.0316065, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.760731, Final residual = 0.0524181, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.649458, Final residual = 0.0508126, No Iterations 1
GAMG: Solving for p, Initial residual = 0.965877, Final residual = 0.00695088, No Iterations 7
GAMG: Solving for p, Initial residual = 0.284313, Final residual = 0.00135296, No Iterations 3
time step continuity errors : sum local = 0.00278298, global = -0.000389391, cumulative = -0.000536535
DILUPBiCG: Solving for epsilon, Initial residual = 0.944274, Final residual = 0.0104053, No Iterations 2
DILUPBiCG: Solving for k, Initial residual = 0.984862, Final residual = 0.0866853, No Iterations 1
ExecutionTime = 22.05 s ClockTime = 44 s
Time = 0.003
DILUPBiCG: Solving for Ux, Initial residual = 0.2867, Final residual = 0.0118204, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.613741, Final residual = 0.0435605, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.610194, Final residual = 0.0566501, No Iterations 1
GAMG: Solving for p, Initial residual = 0.849475, Final residual = 0.00591298, No Iterations 7
GAMG: Solving for p, Initial residual = 0.408281, Final residual = 0.0022316, No Iterations 3
time step continuity errors : sum local = 0.00442252, global = -0.000694598, cumulative = -0.00123113
DILUPBiCG: Solving for epsilon, Initial residual = 0.0269077, Final residual = 0.00258516, No Iterations 1
bounding epsilon, min: -636276 max: 1.63604e+10 average: 633200
DILUPBiCG: Solving for k, Initial residual = 0.480218, Final residual = 0.0114333, No Iterations 2
ExecutionTime = 31.11 s ClockTime = 62 s
...
|
I don't know what to do anymore - I've tried a lot of different settings.
These are my settings:
k
Quote:
internalField uniform 0.375;
boundaryField
{
Inlet
{
type fixedValue;
value uniform 0.375;
}
Outlet
{
type zeroGradient;
}
Leitung_11
{
type kqRWallFunction;
value $internalField;
}
...
|
epsilon
Quote:
internalField uniform 14.855;
boundaryField
Inlet
{
type fixedValue;
value uniform 14.855;
}
Outlet
{
type zeroGradient;
}
Leitung_11
{
type epsilonWallFunction;
value $internalField;
}...
|
U
Quote:
internalField uniform (0 0 0);
boundaryField
{
Inlet
{
type fixedValue;
value uniform (1.7466 0 0);
}
Outlet
{
type zeroGradient;
}
Leitung_11
{
type zeroGradient;
value $internalField;
}
|
p
Quote:
internalField uniform 0;
boundaryField
{
Inlet
{
type fixedValue;
value uniform 7638;
}
Outlet
{
type zeroGradient;
}
Leitung_11
{
type zeroGradient;
} ...
|
nut
Quote:
internalField uniform 0;
boundaryField
{
Inlet
{
type calculated;
value uniform 0;
}
Outlet
{
type calculated;
value uniform 0;
}
Leitung_11
{
type nutWallFunction;
value uniform 0;
}...
|
nuTilda
Quote:
internalField uniform 0;
boundaryField
{
Inlet
{
type fixedValue;
value uniform 0;
}
Outlet
{
type fixedValue;
value uniform 0;
}
Leitung_11
{
type zeroGradient;
value $internalField;
}...
|
R
Quote:
internalField uniform (0 0 0 0 0 0);
boundaryField
{
Inlet
{
type fixedValue;
value uniform (0 0 0 0 0 0);
}
Outlet
{
type zeroGradient;
}
Leitung_11
{
type kqRWallFunction;
}
...
|
boundary
Quote:
26
(
Inlet
{
type patch;
nFaces 328;
startFace 3575458;
}
Outlet
{
type patch;
nFaces 502;
startFace 3575786;
}
Leitung_11
{
type wall;
nFaces 16315;
startFace 3576288;
}...
|
Sorry for the long post! |
