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rigidBodyMotion: Change the transform averaging to use approximate inverse-distance weighting

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Now works correctly for an arbitrary number of bodies
Resolves bug-report http://bugs.openfoam.org/view.php?id=2211
This commit is contained in:
Henry Weller 2016-09-15 14:36:20 +01:00
parent 1ca4bbf1d2
commit de29a3309e
2 changed files with 38 additions and 10 deletions
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40
src/rigidBodyDynamics/rigidBodyMotion/rigidBodyMotion.C
View file

@ -50,7 +50,7 @@ Foam::RBD::rigidBodyMotion::rigidBodyMotion()
aRelax_(1.0),
aDamp_(1.0),
report_(false),
solver_(NULL)
solver_(nullptr)
{}
Foam::RBD::rigidBodyMotion::rigidBodyMotion
@ -178,6 +178,28 @@ void Foam::RBD::rigidBodyMotion::status(const label bodyID) const
}
Foam::tmp<Foam::pointField> Foam::RBD::rigidBodyMotion::transformPoints
(
const label bodyID,
const pointField& initialPoints
) const
{
// Calculate the transform from the initial state in the global frame
// to the current state in the global frame
spatialTransform X(X0(bodyID).inv() & X00(bodyID));
tmp<pointField> tpoints(new pointField(initialPoints.size()));
pointField& points = tpoints.ref();
forAll(points, i)
{
points[i] = X.transformPoint(initialPoints[i]);
}
return tpoints;
}
Foam::tmp<Foam::pointField> Foam::RBD::rigidBodyMotion::transformPoints
(
const label bodyID,
@ -249,25 +271,23 @@ Foam::tmp<Foam::pointField> Foam::RBD::rigidBodyMotion::transformPoints
forAll(points, i)
{
// Sum (1 - wi) and find the maximum wi
scalar sum1mw = 0;
scalar maxw = 0;
// Initialize to 1 for the far-field weight
scalar sum1mw = 1;
forAll(bodyIDs, bi)
{
w[bi] = (*(weights[bi]))[i];
sum1mw += 1 - w[bi];
maxw = max(maxw, w[bi]);
sum1mw += w[bi]/(1 + SMALL - w[bi]);
}
// Calculate the limiter for (1 - wi) to ensure the sum(wi) = maxw
scalar lambda = (w.size() - 1 - maxw)/sum1mw;
// Calculate the limiter for wi/(1 - wi) to ensure the sum(wi) = 1
scalar lambda = 1/sum1mw;
// Limit (1 - wi) and sum the resulting wi
// Limit wi/(1 - wi) and sum the resulting wi
scalar sumw = 0;
forAll(bodyIDs, bi)
{
w[bi] = 1 - lambda*(1 - w[bi]);
w[bi] = lambda*w[bi]/(1 + SMALL - w[bi]);
sumw += w[bi];
}

8
src/rigidBodyDynamics/rigidBodyMotion/rigidBodyMotion.H
View file

@ -183,6 +183,14 @@ public:
// Transformations
//- Transform the given initial pointField of the specified body
// to correspond to the current motion state
tmp<pointField> transformPoints
(
const label bodyID,
const pointField& initialPoints
) const;
//- Transform the given initial pointField of the specified body
// to correspond to the current motion state scaled using
// 'slerp' interpolation