CFD Online Discussion Forums - About the force calculation in sixDoFRigidBodyMotion.C

Dear all,
I started to dig into the code of the sixDoFRigidBodyMotion.C while I am running several cases on vortex induced vibration with pimpleDyMFoam from OF2.4.0.
The motion solver employs the leapfrog algorithm:

Code:

        // Update state



            //- First leapfrog velocity adjust and motion part, required

            //  before force calculation.  Takes old timestep for variable

            //  timestep cases.

            void updatePosition(scalar deltaT, scalar deltaT0);



            //- Second leapfrog velocity adjust part

            //  required after motion and force calculation

            void updateAcceleration

            (

                const vector& fGlobal,

                const vector& tauGlobal,

                scalar deltaT

            );

(a clip from sixDoFRigidBodyMotion.H)

In my case, the fGlobal needs to be calculated from the fluidic forces on the cylinder and the linear damping and stiffness from the a spring. This force calculation procedure should be done before the second leapfrog to update the acceleration. However, I cannot find any code in the .C file relating how the fluidic forces are incorporated.

Am I missing something here? Please give me a hint!