FreeFOAM The Cross-Platform CFD Toolkit
Gamma.H
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1 /*---------------------------------------------------------------------------*\
2  ========= |
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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10 
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23 
24 Class
25  Foam::GammaLimiter
26 
27 Description
28  Class with limiter function which returns the limiter for the
29  Gamma differencing scheme based on phict obtained from the LimiterFunc
30  class.
31 
32  Used in conjunction with the template class LimitedScheme.
33 
34 SourceFiles
35  Gamma.C
36 
37 \*---------------------------------------------------------------------------*/
38 
39 #ifndef Gamma_H
40 #define Gamma_H
41 
42 #include <OpenFOAM/vector.H>
43 
44 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
45 
46 namespace Foam
47 {
48 
49 /*---------------------------------------------------------------------------*\
50  Class GammaLimiter Declaration
51 \*---------------------------------------------------------------------------*/
52 
53 template<class LimiterFunc>
55 :
56  public LimiterFunc
57 {
58  scalar k_;
59 
60 public:
61 
63  :
64  k_(readScalar(is))
65  {
66  if (k_ < 0 || k_ > 1)
67  {
68  FatalIOErrorIn("GammaLimiter(Istream& is)", is)
69  << "coefficient = " << k_
70  << " should be >= 0 and <= 1"
71  << exit(FatalIOError);
72  }
73 
74  // Rescale k_ to be >= 0 and <= 0.5 (TVD conformant)
75  // and avoid the /0 when k_ = 0
76  k_ = max(k_/2.0, 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 phict = LimiterFunc::phict
91  (
92  faceFlux, phiP, phiN, gradcP, gradcN, d
93  );
94 
95  return min(max(phict/k_, 0), 1);
96  }
97 };
98 
99 
100 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
101 
102 } // End namespace Foam
103 
104 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
105 
106 #endif
107 
108 // ************************ vim: set sw=4 sts=4 et: ************************ //