The motion of the bodies is integrated using the rigidBodyDynamics
library with joints, restraints and external forces.
The mesh-motion is interpolated using septernion averaging.
This development is sponsored by Carnegie Wave Energy Ltd.
inline Foam::vector Foam::septernion::transformPoint(const vector& v) const
{
return r().transform(v - t());
}
Now there is a 1:1 correspondence between septernion and
spatialTransform and a septernion constructor from spatialTransform
provided.
Additionally "septernion::transform" has been renamed
"septernion::transformPoint" to clarify that it transforms coordinate
points rather than displacements or other relative vectors.
'w' is now obtained from 'v' using the relation w = sqrt(1 - |sqr(v)|)
and 'v' is stored in the joint state field 'q' and integrated in the
usual manner but corrected using quaternion transformations.
Currently supported solvers: symplectic, Newmark, CrankNicolson
The symplectic solver should only be used if iteration over the forces
and body-motion is not required. Newmark and CrankNicolson both require
iteration to provide 2nd-order behavior.
See applications/test/rigidBodyDynamics/spring for an example of the
application of the Newmark solver.
This development is sponsored by Carnegie Wave Energy Ltd.
This is a more convenient way of maintaining the state or multiple
states (for higher-order integration), storing, retrieving and passing
between processors.
Included for backward-compatibility with the 6-DoF solver but in the
future will be re-implemented as a joint rather than body restraint and
accumulated in tau (internal forces) rather than fx (external forces).
applications/test/rigidBodyDynamics/spring: Test of the linear spring with damper restraint
Damped simple harmonic motion of a weight on a spring is simulated and
the results compared with analytical solution
Test-spring
gnuplot spring.gnuplot
evince spring.eps
This development is sponsored by Carnegie Wave Energy Ltd.
e.g. (fvc::interpolate(HbyA) & mesh.Sf()) -> fvc::flux(HbyA)
This removes the need to create an intermediate face-vector field when
computing fluxes which is more efficient, reduces the peak storage and
improved cache coherency in addition to providing a simpler and cleaner
API.
