Hello, has anyone have a modif
 

Hello, has anyone have a modified liftDrag utility for use with the compressible flow solvers such as rhopSonicFoam?

I note that the incompressible version uses nu and not mu. My C++ is not up to scratch. Any assistance would be appreciated.

Thanks

Shaun.D

Hello Shaun, Yes, I have mo
 

Hello Shaun,

Yes, I have modified liftDrag.

An enhanced version of liftDrag has the next features:
- support incompressible and compressible solvers (Euler equations, laminar, turbulent);
- user can specify drag force direction and reference values;
- forces and moments (not coefficients) printed when the option dimensioned is specified.

You can download it from this:
http://mmpp.110mb.com/OpenFOAM/liftDragTool.tar.gz

Be careful the new version overwrite old liftDrag files.

I also want to upload it to svn. Does anyone known Do I need registration on svn to upload files?

Ivan

Hello Ivan, Thanks for repl
 

Hello Ivan,

Thanks for replying and thank you for the updated tool.

I am not sure about the registration process.

Regards

Shaun.D

Hi Ivan, thanks for sharing
 

Hi Ivan,

thanks for sharing the updated liftdrag tool.

I was just wondering what you've taken as the moment origin?

thanks,
Laurence

Hello Laurence, The moment
 

Hello Laurence,

The moment origin is the origin of the coordinate system. The same as in earlier liftDrag.

I also found that reference density, velocity and others reference values can be computed incorrectly for compressible flow. So you can use the option -dimensionless or manually set reference values for compressible flow.

Ivan

Hi Ivan, I'm a newbie at wr
 

Hi Ivan,

I'm a newbie at writing C++ code so forgive me if this is an obvious question but I was looking through the liftDrag utility you modified and was wondering how the "dragCoefficient" variable in incompressible.H finds the turbulent drag coefficient in liftDrag.H in the src/... folder. Why don't we have to change the "dragCoefficent" in the incompressible.H file to "turbDragCoefficient" to get the drag coefficient that includes turbulent effects?

Thanks,

Simon.

Hey, I was stumbling over t
 

Hey,

I was stumbling over the same thing. Any clues yet? I'm sure the turbLift/DragCoefficient function is never called...
I'll try fixing it, but don't know if I'll succeed.

My problem is that I have no idea how to find out which turbulence model is used, which is needed for the turbLiftCoefficient function as the first argument:
const autoPtr<turbulencemodel>& turbulence

And if you want to make this a smooth function, you have to find out automatically in advance whether it's a turbulent or laminar simulation, and which model is used.

Cheers,

Axel

Looking at the latest 1.5 rele
 

Looking at the latest 1.5 release, it seems the liftDrag utility is obsolete now, there is a new force postprocessor in 1.5. I haven't tested it yet but it might be just what you are looking for.

I followed the instructions fo
 

I followed the instructions for installing the enhanced version of the liftDrag utility on OF 1.4.1-dev, but got the following error when running wmake:

liftDrag.C: In function 'int main(int, char**)':
liftDrag.C:89: error: no match for 'operator=' in 'nu = transportProperties.Foam::IOdictionary::<anonymous >.Foam::dictionary::lookup(((c onst Foam::word&)(& Foam::word(((const char*)"nu")))))'

Any ideas?

Hello Friends http://www.cfd-o
 

Hello Friends http://www.cfd-online.com/OpenFOAM_D...part/happy.gif

I am curious to know how to get the values of lift and drag coefficients from log file for flow across a cylinder case in OpenFOam 1.5?