FreeFOAM The Cross-Platform CFD Toolkit
DeardorffDiffStress.H
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23 
24 Class
25  Foam::incompressible::LESModels::DeardorffDiffStress
26 
27 Description
28  Differential SGS Stress Equation Model for incompressible flows
29 
30  The DSEM uses a model version of the full balance equation for the SGS
31  stress tensor to simulate the behaviour of B.
32  Thus,
33  @verbatim
34  d/dt(B) + div(U*B) - div(nuSgs*grad(B))
35  =
36  P - c1*epsilon/k*B - 0.667*(1 - c1)*epsilon*I - c2*(P - 0.333*trP*I)
37 
38  where
39 
40  k = 0.5*tr(B),
41  epsilon = ce*k^3/2/delta,
42  epsilon/k = ce*k^1/2/delta
43  P = -(B'L + L'B)
44  nuSgs = ck*sqrt(k)*delta
45  nuEff = nuSgs + nu
46  @endverbatim
47 
48 SourceFiles
49  DeardorffDiffStress.C
50 
51 \*---------------------------------------------------------------------------*/
52 
53 #ifndef DeardorffDiffStress_H
54 #define DeardorffDiffStress_H
55 
57 
58 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
59 
60 namespace Foam
61 {
62 namespace incompressible
63 {
64 namespace LESModels
65 {
66 
67 /*---------------------------------------------------------------------------*\
68  Class DeardorffDiffStress Declaration
69 \*---------------------------------------------------------------------------*/
70 
72 :
73  public GenSGSStress
74 {
75  // Private data
76 
79 
80 
81  // Private Member Functions
82 
83  //- Update sub-grid scale fields
84  void updateSubGridScaleFields(const volScalarField& K);
85 
86  // Disallow default bitwise copy construct and assignment
88  DeardorffDiffStress& operator=(const DeardorffDiffStress&);
89 
90 
91 public:
92 
93  //- Runtime type information
94  TypeName("DeardorffDiffStress");
95 
96  // Constructors
97 
98  //- Construct from components
100  (
101  const volVectorField& U,
102  const surfaceScalarField& phi,
104  );
105 
106 
107  //- Destructor
109  {}
110 
111 
112  // Member Functions
113 
114  //- Return the effective diffusivity for B
116  {
117  return tmp<volScalarField>
118  (
119  new volScalarField("DBEff", nuSgs_ + nu())
120  );
121  }
122 
123  //- Correct Eddy-Viscosity and related properties
124  virtual void correct(const tmp<volTensorField>& gradU);
125 
126  //- Read LESProperties dictionary
127  virtual bool read();
128 };
129 
130 
131 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
132 
133 } // End namespace LESModels
134 } // End namespace incompressible
135 } // End namespace Foam
136 
137 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
138 
139 #endif
140 
141 // ************************ vim: set sw=4 sts=4 et: ************************ //