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symplectic.C
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1/*---------------------------------------------------------------------------*\
2 ========= |
3 \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
4 \\ / O peration |
5 \\ / A nd | www.openfoam.com
6 \\/ M anipulation |
7-------------------------------------------------------------------------------
8 Copyright (C) 2015-2016 OpenFOAM Foundation
9 Copyright (C) 2023 OpenCFD Ltd.
10-------------------------------------------------------------------------------
11License
12 This file is part of OpenFOAM.
13
14 OpenFOAM is free software: you can redistribute it and/or modify it
15 under the terms of the GNU General Public License as published by
16 the Free Software Foundation, either version 3 of the License, or
17 (at your option) any later version.
18
19 OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
20 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 for more details.
23
24 You should have received a copy of the GNU General Public License
25 along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
26
27\*---------------------------------------------------------------------------*/
28
29#include "symplectic.H"
32// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
33
34namespace Foam
35{
36namespace sixDoFSolvers
37{
40}
41}
42
43
44// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
45
47(
48 const dictionary& dict,
50)
52 sixDoFSolver(dict, body)
53{}
54
55
56// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
59{}
60
61
62// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
63
65(
66 bool firstIter,
67 const vector& fGlobal,
68 const vector& tauGlobal,
69 scalar deltaT,
70 scalar deltaT0
71)
72{
73 // First simplectic step:
74 // Half-step for linear and angular velocities
75 // Update position and orientation
76
77 v() = tConstraints() & (v0() + aDamp()*0.5*deltaT0*a0());
78 pi() = rConstraints() & (pi0() + aDamp()*0.5*deltaT0*tau0());
79
80 centreOfRotation() = centreOfRotation0() + deltaT*v();
81
82 Tuple2<tensor, vector> Qpi = rotate(Q0(), pi(), deltaT);
83 Q() = Qpi.first();
84 pi() = rConstraints() & Qpi.second();
85
86 // Update the linear acceleration and torque
87 updateAcceleration(fGlobal, tauGlobal);
88
89 // Update the constraints to the object
90 updateConstraints();
91
92 // Second simplectic step:
93 // Complete update of linear and angular velocities
94
95 v() += tConstraints() & aDamp()*0.5*deltaT*a();
96 pi() += rConstraints() & aDamp()*0.5*deltaT*tau();
97}
98
99// ************************************************************************* //
constexpr scalar pi(M_PI)
Macros for easy insertion into run-time selection tables.
#define addToRunTimeSelectionTable(baseType, thisType, argNames)
Add to construction table with typeName as the key.
A 2-tuple for storing two objects of dissimilar types. The container is similar in purpose to std::pa...
Definition Tuple2.H:51
const T1 & first() const noexcept
Access the first element.
Definition Tuple2.H:132
const T2 & second() const noexcept
Access the second element.
Definition Tuple2.H:142
A list of keyword definitions, which are a keyword followed by a number of values (eg,...
Definition dictionary.H:133
Six degree of freedom motion for a rigid body.
tensor tConstraints() const
Translational constraint tensor.
void updateAcceleration(const vector &fGlobal, const vector &tauGlobal)
Update and relax accelerations from the force and torque.
const vector & tau0() const
Return the torque at previous time-step.
sixDoFSolver(const dictionary &dict, sixDoFRigidBodyMotion &body)
point & centreOfRotation()
Return the current centre of rotation.
const point & centreOfRotation0() const
Return the centre of rotation at previous time-step.
Tuple2< tensor, vector > rotate(const tensor &Q0, const vector &pi, const scalar deltaT) const
Apply rotation tensors to Q0 for the given torque (pi) and deltaT.
void updateConstraints()
Update the constraints to the object.
tensor & Q()
Return the orientation.
scalar aDamp() const
Acceleration damping coefficient (for steady-state simulations).
const vector & v0() const
Return the velocity at previous time-step.
const vector & a0() const
Return the acceleration at previous time-step.
const vector & pi0() const
Return the angular momentum at previous time-step.
const tensor & Q0() const
Return the orientation at previous time-step.
tensor rConstraints() const
Rotational constraint tensor.
vector & a()
Return non-const access to acceleration.
vector & tau()
Return non-const access to torque.
vector & v()
Return non-const access to vector.
Symplectic 2nd-order explicit time-integrator for 6DoF solid-body motion.
Definition symplectic.H:78
virtual ~symplectic()
Destructor.
Definition symplectic.C:51
symplectic(const dictionary &dict, sixDoFRigidBodyMotion &body)
Construct from a dictionary and the body.
Definition symplectic.C:40
virtual void solve(bool firstIter, const vector &fGlobal, const vector &tauGlobal, scalar deltaT, scalar deltaT0)
Drag coefficient.
Definition symplectic.C:58
#define defineTypeNameAndDebug(Type, DebugSwitch)
Define the typeName and debug information.
Definition className.H:142
Namespace for OpenFOAM.
Vector< scalar > vector
Definition vector.H:57
dictionary dict