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-   -   BuoyantPimpleFoam (http://www.cfd-online.com/Forums/openfoam-solving/98634-buoyantpimplefoam.html)

Wokl March 15, 2012 06:03

BuoyantPimpleFoam
 
Hi Everybody,

I'm totally new using OpenFoam and also new in this Forum. So i hope i chose the right Forum.

My case: A Room, with windows and heaters. 3 Inlets and 3 outlets. Calculating the Flow and the Heat treansfer in this room.

I've got some Problems using the solver buoyantPimpleFoam. I was running my case before with rhoPimpleFoam.
With rhoPF the calculations were ok. The results weren't really as expected, but this is another Problem I'm hopefully able to solve by myselve.

By using the buoyant solver, i had to define the p_rgh field. I'm a little curious bout that: What kind of boundary Condtion should I use for the Inlets and Outlets? Now I'm using for all my Boundary Fields: type BuoyantPressure, value 1.0e5. All my Boundary conditions for my p-field are calculated.

I always get in the Log the Error, that PIMPLE was not able to converge within a chosen number of iterations (max Number tried: 50).

The "good" thing now is, the calculations conitnues allthough this error appears. MY residuals are i guess too high in the beginning of the calculations but they get better the "later" the time is.

I'm using the GAMG solver for the p_rgh field. PBiCG for the other fields.
What does the entry:diagonal: solving for rho in my log mean?

One of the, i guess, more stupid questions, Why do i need to mention rho in my fvSolution file? I thought all the time, this value is gonna be picked out of the thermophysical properties.

here a little sequence of my log:

PIMPLE: iteration 10
DILUPBiCG: Solving for Ux, Initial residual = 0.000117343, Final residual = 2.1435e-07, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 6.34329e-05, Final residual = 8.78097e-08, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.000158416, Final residual = 3.27881e-07, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.000315353, Final residual = 3.37565e-06, No Iterations 1
GAMG: Solving for p_rgh, Initial residual = 0.00251756, Final residual = 9.53852e-07, No Iterations 7
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 2.37145e-06, global = 2.37145e-06, cumulative = 0.0449056
DILUPBiCG: Solving for epsilon, Initial residual = 0.0466574, Final residual = 6.76327e-06, No Iterations 1
bounding epsilon, min: -0.0027499 max: 20.61 average: 0.000581218
DILUPBiCG: Solving for k, Initial residual = 0.00332098, Final residual = 1.42397e-05, No Iterations 1
PIMPLE: not converged within 10 iterations
ExecutionTime = 1507.22 s ClockTime = 1510 s

I hope I didn't write too confusing.

Thank u in advance
Christian

P.S. CheckMesh was telling Mesh ok

Akuji June 21, 2012 03:55

Quote:

Originally Posted by Wokl (Post 349563)
Hi Everybody,

I'm totally new using OpenFoam and also new in this Forum. So i hope i chose the right Forum.

My case: A Room, with windows and heaters. 3 Inlets and 3 outlets. Calculating the Flow and the Heat treansfer in this room.

I've got some Problems using the solver buoyantPimpleFoam. I was running my case before with rhoPimpleFoam.
With rhoPF the calculations were ok. The results weren't really as expected, but this is another Problem I'm hopefully able to solve by myselve.

By using the buoyant solver, i had to define the p_rgh field. I'm a little curious bout that: What kind of boundary Condtion should I use for the Inlets and Outlets? Now I'm using for all my Boundary Fields: type BuoyantPressure, value 1.0e5. All my Boundary conditions for my p-field are calculated.

I always get in the Log the Error, that PIMPLE was not able to converge within a chosen number of iterations (max Number tried: 50).

The "good" thing now is, the calculations conitnues allthough this error appears. MY residuals are i guess too high in the beginning of the calculations but they get better the "later" the time is.

I'm using the GAMG solver for the p_rgh field. PBiCG for the other fields.
What does the entry:diagonal: solving for rho in my log mean?

One of the, i guess, more stupid questions, Why do i need to mention rho in my fvSolution file? I thought all the time, this value is gonna be picked out of the thermophysical properties.

here a little sequence of my log:

PIMPLE: iteration 10
DILUPBiCG: Solving for Ux, Initial residual = 0.000117343, Final residual = 2.1435e-07, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 6.34329e-05, Final residual = 8.78097e-08, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.000158416, Final residual = 3.27881e-07, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.000315353, Final residual = 3.37565e-06, No Iterations 1
GAMG: Solving for p_rgh, Initial residual = 0.00251756, Final residual = 9.53852e-07, No Iterations 7
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 2.37145e-06, global = 2.37145e-06, cumulative = 0.0449056
DILUPBiCG: Solving for epsilon, Initial residual = 0.0466574, Final residual = 6.76327e-06, No Iterations 1
bounding epsilon, min: -0.0027499 max: 20.61 average: 0.000581218
DILUPBiCG: Solving for k, Initial residual = 0.00332098, Final residual = 1.42397e-05, No Iterations 1
PIMPLE: not converged within 10 iterations
ExecutionTime = 1507.22 s ClockTime = 1510 s

I hope I didn't write too confusing.

Thank u in advance
Christian

P.S. CheckMesh was telling Mesh ok

Hello, Wokl!

have you solved your problem? I have the same now and I'm looking for solution. maybe you can give me some advices?


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