[sabbraxcaddabra]

Hello everyone!

My problem is: in axisymmetric case (zero AoA) there x-axis is axis of symmetry I have a very small drag force and some lift force that is unreallistic (axisymmetric body with zero AoA dont have lift force).

I guess that problem in how OF intergate pressure and stress over the body surface, but may there are correct solution for that case&

[Yann]

Hello Vadim,

It would probably be useful to see how you defined your forces function in order to see what could be wrong.

[sabbraxcaddabra]

Thank you for your reply

This is my forces file code

#includeEtc "caseDicts/postProcessing/forces/forces.cfg"

patches     (body); // Names of patches on which to calculate forces

CofR        (0 0 0);         // Centre of rotation; e.g., (0 0 0)

[Yann]

I'm surprised it runs as it is.
Which OpenFOAM version are you using ? And which solver?

This line:

#includeEtc "caseDicts/postProcessing/forces/forces.cfg"

Is pointing to a configuration file in the OpenFOAM installation directory.

You may want to check which settings are used there, or define the whole function by yourself to be sure all parameters are set properly for your case (density, coordinate system...)

[sabbraxcaddabra]

Im using OpenFOAM-v2312 and rhoPimpleFoam solver
And this is forces.cfg file code

type            forces;
libs            ("libforces.so");

// How often force and moment volume fields will be written
writeControl    writeTime; // none

// How often the forces force.dat and moment.dat data files are updated
// Note: .dat files are always updated on writeControl times
executeControl  timeStep;
executeInterval 1;

log             off;

[Yann]

You can have a look here for a more complete description of the function: https://develop.openfoam.com/Develop...orces/forces.H

What coordinate system are you using in your case?