FreeFOAM The Cross-Platform CFD Toolkit
limitedCubic.H
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3  \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
4  \\ / O peration |
5  \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd.
6  \\/ M anipulation |
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23 
24 Class
25  Foam::limitedCubicLimiter
26 
27 Description
28  Class with limiter function which returns the limiter for the
29  TVD limited centred-cubic differencing scheme based on r obtained from
30  the LimiterFunc class.
31 
32  Used in conjunction with the template class LimitedScheme.
33 
34 SourceFiles
35  limitedCubic.C
36 
37 \*---------------------------------------------------------------------------*/
38 
39 #ifndef limitedCubic_H
40 #define limitedCubic_H
41 
42 #include <OpenFOAM/vector.H>
43 
44 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
45 
46 namespace Foam
47 {
48 
49 /*---------------------------------------------------------------------------*\
50  Class limitedCubicLimiter Declaration
51 \*---------------------------------------------------------------------------*/
52 
53 template<class LimiterFunc>
55 :
56  public LimiterFunc
57 {
58  scalar k_;
59  scalar twoByk_;
60 
61 public:
62 
64  :
65  k_(readScalar(is))
66  {
67  if (k_ < 0 || k_ > 1)
68  {
69  FatalIOErrorIn("limitedCubicLimiter(Istream& is)", is)
70  << "coefficient = " << k_
71  << " should be >= 0 and <= 1"
72  << exit(FatalIOError);
73  }
74 
75  // Avoid the /0 when k_ = 0
76  twoByk_ = 2.0/max(k_, SMALL);
77  }
78 
79  scalar limiter
80  (
81  const scalar cdWeight,
82  const scalar faceFlux,
83  const typename LimiterFunc::phiType& phiP,
84  const typename LimiterFunc::phiType& phiN,
85  const typename LimiterFunc::gradPhiType& gradcP,
86  const typename LimiterFunc::gradPhiType& gradcN,
87  const vector& d
88  ) const
89  {
90  scalar twor = twoByk_*LimiterFunc::r
91  (
92  faceFlux, phiP, phiN, gradcP, gradcN, d
93  );
94 
95  scalar phiU;
96 
97  if (faceFlux > 0)
98  {
99  phiU = phiP;
100  }
101  else
102  {
103  phiU = phiN;
104  }
105 
106  // Calculate the face value using cubic interpolation
107  scalar phif =
108  cdWeight*(phiP - 0.25*(d & gradcN))
109  + (1 - cdWeight)*(phiN + 0.25*(d & gradcP));
110 
111  scalar phiCD = cdWeight*phiP + (1 - cdWeight)*phiN;
112 
113  // Calculate the effective limiter for the cubic interpolation
114  scalar cubicLimiter = (phif - phiU)/stabilise(phiCD - phiU, SMALL);
115 
116  /*
117  if (twor < 0.05)
118  {
119  cubicLimiter = twor;
120  }
121 
122  return max(min(cubicLimiter, 2), 0);
123  */
124 
125  // Limit the limiter to obey the TVD constraint
126  return max(min(min(twor, cubicLimiter), 2), 0);
127  }
128 };
129 
130 
131 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
132 
133 } // End namespace Foam
134 
135 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
136 
137 #endif
138 
139 // ************************ vim: set sw=4 sts=4 et: ************************ //