Description
Time-dependent external force restraint using Function1.
Usage
Example applying a constant force to the floatingObject:
restraints
{
force
{
type externalForce;
body floatingObject;
location (0 0 0);
force (100 0 0);
}
}
Based on code contributed by SeongMo Yeon
Resolves contribution request https://bugs.openfoam.org/view.php?id=3358
Description
Time-dependent external force restraint using Function1.
Usage
Example applying a constant force to the floatingObject:
restraints
{
force
{
type externalForce;
body floatingObject;
location (0 0 0);
force (100 0 0);
}
}
Based on code contributed by SeongMo Yeon
Resolves contribution request https://bugs.openfoam.org/view.php?id=3358
Provides access to properties of the model and current state for complex and
time-dependent restraints.
Patch contributed by SeongMo Yeon
Resolves contribution https://bugs.openfoam.org/view.php?id=3345#c10787
and removed the need for the direct dependency of Ostream on keyType which is
not a primitive IO type and relates specifically to dictionary and not all IO.
and copy assignment operator for classes with a copy constructor
This is often described as the rule of 3 (or rule of 5 in C++11 if move
constructors and assignment operators are also defined) and makes good sense in
ensuring consistency. For classes in which the default bitwise copy constructor
or assignment operator are appropriate these are now specified explicitly using
the "= default" keyword if the other is explicitly defined fulfilling the rule
of 3 without the need to define the body of the function.
Currently these deleted function declarations are still in the private section
of the class declarations but will be moved by hand to the public section over
time as this is too complex to automate reliably.
Replaced all uses of complex Xfer class with C++11 "move" constructors and
assignment operators. Removed the now redundant Xfer class.
This substantial changes improves consistency between OpenFOAM and the C++11 STL
containers and algorithms, reduces memory allocation and copy overhead when
returning containers from functions and simplifies maintenance of the core
libraries significantly.
The new "rigid" joint permits no motion at all, "function" specifies the
position of the joint as a function of the position of it's parent, and
"functionDot" specifies the position of the joint as a function of the
velocity of it's parent. Note that the functions are applied uniformly
to each component of the parent joint's position/motion. Example
specifications are shown below.
joint
{
type rigid;
}
joint
{
type function;
function table ((-1 0) (0 1) (1 0));
}
joint
{
type functionDot;
function table ((-1 0) (0 1) (1 0));
}
This work was supported by Caitlin Worden Hodge, at Zyba
This allows for fixed joints or joints which completely constrain the
motion as a function of some other aspect of the model. The latter has
also been facilitaed by adding a reference to the rigid body model to
the base joint class.
In early versions of OpenFOAM the scalar limits were simple macro replacements and the
names were capitalized to indicate this. The scalar limits are now static
constants which is a huge improvement on the use of macros and for consistency
the names have been changed to camel-case to indicate this and improve
readability of the code:
GREAT -> great
ROOTGREAT -> rootGreat
VGREAT -> vGreat
ROOTVGREAT -> rootVGreat
SMALL -> small
ROOTSMALL -> rootSmall
VSMALL -> vSmall
ROOTVSMALL -> rootVSmall
The original capitalized are still currently supported but their use is
deprecated.
The absolute value of the the time has been added to the rigid body
model state. This value is not directly necessary for calculating the
evolution of the rigid body system, it just facilitates the
implementation of sub-models which are in some way time-dependent.
The restraints generate either joint-local (tau) or global (fx) forces.
At the moment they all generate the latter. This change corrects three
of the four restraints so that the forces are in the gobal coordinate
system and not the local coordinate system of the body.
The problem with this is that the forward dynamics code then transforms
most of the forces back to the body local coordinate system. A better
solution would be to associate restraints which are more sensibly
defined in a local frame with the joints instead of the bodies, and
return the forces as part of the tau variable.
The joint-space dynamics is solved on the master processor only and the
resulting joint-state distributed to the slave processors on which the
body-state is then updated. This guarantees consistency of the body
position and orientation on all processors.
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.
'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.
