pitchForkRing.C
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1 /*---------------------------------------------------------------------------*\
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3  \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
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5  \\ / A nd | Copyright (C) 2011 OpenFOAM Foundation
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25 
26 #include "pitchForkRing.H"
28 
29 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
30 
31 namespace Foam
32 {
33 namespace tetherPotentials
34 {
35 
36 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
37 
38 defineTypeNameAndDebug(pitchForkRing, 0);
39 
41 (
42  tetherPotential,
43  pitchForkRing,
44  dictionary
45 );
46 
47 
48 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
49 
51 (
52  const word& name,
53  const dictionary& tetherPotentialProperties
54 )
55 :
56  tetherPotential(name, tetherPotentialProperties),
57  pitchForkRingCoeffs_
58  (
59  tetherPotentialProperties.subDict(typeName + "Coeffs")
60  ),
61  mu_(readScalar(pitchForkRingCoeffs_.lookup("mu"))),
62  alpha_(readScalar(pitchForkRingCoeffs_.lookup("alpha"))),
63  rOrbit_(readScalar(pitchForkRingCoeffs_.lookup("rOrbit")))
64 {}
65 
66 
67 // * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
68 
69 scalar pitchForkRing::energy(const vector r) const
70 {
71  scalar p = sqrt(r.x()*r.x() + r.y()*r.y());
72 
73  scalar pMinusRSqr = sqr(p - rOrbit_);
74 
75  return
76  -0.5 * mu_ * pMinusRSqr
77  + 0.25 * pMinusRSqr * pMinusRSqr
78  + 0.5 * alpha_ * r.z() * r.z();
79 }
80 
81 
83 {
84  scalar p = sqrt(r.x()*r.x() + r.y()*r.y());
85 
86  scalar pMinusR = (p - rOrbit_);
87 
88  return vector
89  (
90  (mu_ - sqr(pMinusR)) * pMinusR * r.x()/(p + VSMALL),
91  (mu_ - sqr(pMinusR)) * pMinusR * r.y()/(p + VSMALL),
92  - alpha_ * r.z()
93  );
94 }
95 
96 
97 bool pitchForkRing::read(const dictionary& tetherPotentialProperties)
98 {
99  tetherPotential::read(tetherPotentialProperties);
100 
101  pitchForkRingCoeffs_ =
102  tetherPotentialProperties.subDict(typeName + "Coeffs");
103 
104  pitchForkRingCoeffs_.lookup("mu") >> mu_;
105  pitchForkRingCoeffs_.lookup("alpha") >> alpha_;
106  pitchForkRingCoeffs_.lookup("rOrbit") >> rOrbit_;
107 
108  return true;
109 }
110 
111 
112 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
113 
114 } // End namespace tetherPotentials
115 } // End namespace Foam
116 
117 // ************************************************************************* //
dimensionedScalar sqrt(const dimensionedScalar &ds)
pitchForkRing(const word &name, const dictionary &tetherPotentialProperties)
Construct from components.
Definition: pitchForkRing.C:51
addToRunTimeSelectionTable(tetherPotential, harmonicSpring, dictionary)
A class for handling words, derived from string.
Definition: word.H:59
defineTypeNameAndDebug(harmonicSpring, 0)
A list of keyword definitions, which are a keyword followed by any number of values (e...
Definition: dictionary.H:137
const dictionary & subDict(const word &) const
Find and return a sub-dictionary.
Definition: dictionary.C:638
Namespace for OpenFOAM.
const Cmpt & y() const
Definition: VectorI.H:71
volScalarField & p
Definition: createFields.H:51
vector force(const vector r) const
Definition: pitchForkRing.C:82
bool readScalar(const char *buf, doubleScalar &s)
Read whole of buf as a scalar. Return true if succesful.
Definition: doubleScalar.H:63
const Cmpt & x() const
Definition: VectorI.H:65
bool read(const dictionary &tetherPotentialProperties)
Read dictionary.
Definition: pitchForkRing.C:97
Macros for easy insertion into run-time selection tables.
const Cmpt & z() const
Definition: VectorI.H:77
ITstream & lookup(const word &, bool recursive=false, bool patternMatch=true) const
Find and return an entry data stream.
Definition: dictionary.C:452
scalar energy(const vector r) const
Definition: pitchForkRing.C:69
Vector< scalar > vector
A scalar version of the templated Vector.
Definition: vector.H:49
dimensionedSymmTensor sqr(const dimensionedVector &dv)
virtual bool read(const dictionary &tetherPotentialProperties)=0
Read tetherPotential dictionary.