[shawn]

Hi,
I was wondering if anyone had an example of using the twoLiquidMixingFoam solver that they would be willing to share? The user and programer's reference don't seem to have one. I am interested in modeling some microfluidic mixers.

Cheers

Shawn Pfeil

[hjasak]

Enjoy,

twoStream.tgz

Hrv

[shawn]

I noticed in the controlDictionary the solver is interFoam is twoLiquidMixingFoam not used? I'm a little bit of a newbie.

Thanks,

[shawn]

Hi Hrv, (and others)
I went to run the example you sent and got the following error:

--> FOAM FATAL ERROR : gradientInternalCoeffs cannot be called for a defaultFvPatchField.
(Actual type fixedMeanValue)
You are probably trying to solve for a field with a default boundary conditions.

From function defaultFvPatchField<type>::gradientInternalCoeffs( ) const
in file fields/fvPatchFields/basicFvPatchFields/default/defaultFvPatchField.C at line 421.

FOAM exiting

I noticed that when defining the boundary conditions you used an auxilary file outside of the blockMesh dictionary. The file boundary in the polyMesh/ directory. I'm a little new to OpenFOAM and am not entirely sure how this works. If somone has the time to clue me in I would greatly appreciate it. All the examples in the programing guide appear to have b.c.'s self contained in the blockMeshDictonary. Putting them in a seperate file has obvious advantages. I suspect my problem is that I have not figured out how to tell interFoam to look for the boundary file.

Cheers,

Shawn

[hjasak]

Aha, that's one of my new boundary conditions: change it to fixedValue and all will be well.

Hrv

[shawn]

Hi,
I still a little confused. Is defaultFvPatchField a boundary condition you wrote? If so where is it referenced that I need to replace with a fixedValue? I didn't see it in the .OpenFOAM-1.3/Fields directory. Or do I need to replace some of the conditions in the blockMeshDictionary with fixedValue? Sorry for all the newbie questions.

Shawn

[hjasak]

edit 0/pd, line 42: change fixedMeanValue into fixedValue.

In any case, here's an updated version.

Hrv

twoStream.tgz

For the discussion on default b.c. please have a look through the forum - I have already explained this ad nauseum. :-)

[shawn]

I figured it out.

[shawn]

Hi,
I was wondering if their is a simple way to make the viscosity in twoLiquidMixing foam a function of gamma. I am interested in mixing two newtonian liquids where the viscosity is a function of the fraction gamma. It seems like this should be fairly straightforward to code, but I wanted to ask the various c++ and OpenFoam masters before I invest the time. Also, if you could point me to the part of the code I need to tinker with that would be great.

Shawn

[chiven]

Hi, Dear Foamers, I update the example case using twoLiquidMixingFoam solver for OpenFOAM Version 1.6.

Enjoy,
Chiven

[shawn.pfeil]

Hi,

I tried gunzip on the example and got out a binary file. I was expecting some directories? I just updated to OpenFOAM-1.6 and was hoping to find a good example to get up to speed.

[shawn.pfeil]

I realized the file was a .tar.gz file and set up the example. It still gives an error. I ran blockMesh and then twoLiquidMixingFoam. The output is

Create time

Create mesh for time = 0


Reading g
Reading field p_rgh



--> FOAM FATAL IO ERROR:
cannot open file

file: /home/shp/OpenFOAM/OpenFOAM-1.6.x/tutorials/twoStream/0/p_rgh at line 0.

From function regIOobject::readStream()
in file db/regIOobject/regIOobjectRead.C at line 62.

FOAM exiting

field p_rgh is not mentioned in any of the entries under system. What is this?

Shawn

[yannH]

Hi, I think you 've probably forgotten the "step" setFields

try this : blockMesh, setFields and finally twoLiquidMixingFoam

regards

Yann

[maolongliu]

Sorry, I'm using this solver too.
I use your files.
Also I use setFields, but still no p_rgh file.

Originally Posted by yannH

Hi, I think you 've probably forgotten the "step" setFields

try this : blockMesh, setFields and finally twoLiquidMixingFoam

regards

Yann

[heavy_user]

Originally Posted by hjasak

Aha, that's one of my new boundary conditions: change it to fixedValue and all will be well.

Hrv

Hi Hrv,

is there a version of fixedMeanValue for Openfoam 1.6 yet ?
I would be really glad to get hold of it, if possible, since i have been dealing with a problem which might be solved by your boundary condition. But I kind of dislike the thought of going back do OF 1.5...or earlier.

thx & regards

[heavy_user]

omg, never mind my stupidity, plz!

Just figured it out ... for the records, fixedMeanValue works also with OF 1.6..

you need:

files file:

fixedMeanValueFvPatchFields.C

LIB = $(FOAM_USER_LIBBIN)/libfixedMeanValue

The options file needs only:

EXE_INC = \ 
      -I$(LIB_SRC)/finiteVolume/lnInclude

LIB_LIBS = \ 
       -lfiniteVolume

in the control dict you need to add:

libs ( "libfixedMeanValue.so" ) ;

[maolongliu]

This is the one I modified on OpenFOAM 1.6.x.

Originally Posted by maolongliu

Sorry, I'm using this solver too.
I use your files.
Also I use setFields, but still no p_rgh file.

[ziemowitzima]

Dear Foamers,

Does anyone of you know where I can find some informations about model being implemented in TwoLiquidMixingFoam, especially descriptions of the extra terms in NS equations ?
1. (fvc::grad(U) & fvc::grad(muEff))
2. what function reconstruct does ?

fvc::reconstruct
(
fvc::interpolate(rho)*(g & mesh.Sf())
- mesh.magSf()*fvc::snGrad(p)
),
3. Why there is "- mesh.magSf()*fvc::snGrad(p)" to calculate pressure gradient instead of:
"-fvc::grad(p)" ?

Thanks for your help !
ZM

[alberto]

Originally Posted by ziemowitzima

2. what function reconstruct does ?

fvc::reconstruct
(
fvc::interpolate(rho)*(g & mesh.Sf())
- mesh.magSf()*fvc::snGrad(p)
),
3. Why there is "- mesh.magSf()*fvc::snGrad(p)" to calculate pressure gradient instead of:
"-fvc::grad(p)" ?

They use flux reconstruction to introduce the pressure gradient and the buoyancy term (combined now with the introduction of p_rgh) in the momentum predictor. Due to this, the pressure gradient introduced as the contribution it gives to the flux, as argument of reconstruct().

[vrosaless]

Originally Posted by maolongliu

This is the one I modified on OpenFOAM 1.6.x.

Hello

Can you explain more on how to fix the error "p_rgh at line 0"

I get the same error for a case to run a wave Tank. I downloaded the file twoStream.tar.gz and but I got an error like the file is corrupted

gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Exiting with failure status due to previous errors
vrosaless@ubuntu:~/Downloads$ gunzip twoStream.tar.g

Any help is wellcome

Thanks

Victor