Compute drag force on STL file
 

Hi all,
I have successfully installed OpenFOAM and tried to run some tutorial.
I am a complete beginner in this, but I think what I need is very simple. I have an STL file, it is a model of airship. Now, I just need to do a wind tunnel simulation:

- Place the airship in a very large tunnel
- Blow some wind on it at some given speed
- Compute the drag FORCE

Please note that since the definition of reference area is quite blurry when airships are concerned, and the drag coefficient can vary at different wind speeds, I am not interested in the drag coefficient for my model, but just for the drag FORCE for that given specific size and wind velocity. Just a three-components vector, with Newtons as measurement unit ;)

I have seen the motorbike tutorial, and I would have liked to change something in it to make it work. However, I got stuck because:

- It accepts .obj files, how can I make it read an .stl file?
- It computes the drag coefficient, and not the drag force

I feel very naive in this and I am sorry if my question sounds dumb, but I would really need a kick to get started!

Thank you very much indeed

Matteo