[Verse]

Hello,

I've tried defining both centreOfMass and centreOfRotation inside the dynamicMeshDict, as follows:

...
centreOfMass      (0.4 0 0.1)
centreOfRotation (-0.5 0 0.1)
...

After doing this, I recieve an error message as follows:

#0 Foam::error::printStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86-64-linux-gnu/libc.so.6"
...

I see that from the sixDoFRigidBodyMotionState.C code that the solver will default to centreOfMass if the centreOfRotation isn't present:

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2014 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "sixDoFRigidBodyMotionState.H"

// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::sixDoFRigidBodyMotionState::sixDoFRigidBodyMotionState()
:
    centreOfRotation_(vector::zero),
    Q_(I),
    v_(vector::zero),
    a_(vector::zero),
    pi_(vector::zero),
    tau_(vector::zero)
{}


Foam::sixDoFRigidBodyMotionState::sixDoFRigidBodyMotionState
(
    const dictionary& dict
)
:
    centreOfRotation_
    (
        dict.lookupOrDefault
        (
            "centreOfRotation",
            dict.lookupOrDefault("centreOfMass", vector::zero)
        )
    ),
    Q_(dict.lookupOrDefault("orientation", tensor::I)),
    v_(dict.lookupOrDefault("velocity", vector::zero)),
    a_(dict.lookupOrDefault("acceleration", vector::zero)),
    pi_(dict.lookupOrDefault("angularMomentum", vector::zero)),
    tau_(dict.lookupOrDefault("torque", vector::zero))
{}

But surely there should be a way I could define both in the same test case? Including the effects of gravity is significantly important for my test case (but I also need rotation), so having these two variables as separate is very important.

Thank you.