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Lun.H
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23 
24 Class
25  Foam::ParticleStressModels::Lun
26 
27 Description
28  Inter-particle stress model of Lun et al
29 
30  The stress value takes the following form:
31  \f[
32  \left( \alpha \rho + \alpha^2 \rho (1 + e) \frac{3}{5}
33  \left( 1 - \left( \frac{\alpha}{\alpha_{pack}} \right)^\frac{1}{3}
34  \right) \right) \frac{1}{3} \sigma^2
35  \f]
36  Here, \f$\alpha\f$ is the volume fraction of the dispersed phase,
37  \f$\rho\f$ is the density of the dispersed phase, \f$e\f$ is a coefficient
38  of restitution, and \f$\sigma\f$ is the RMS velocity fluctuation.
39 
40  Reference:
41  \verbatim
42  "Kinetic theories for granular flow: inelastic particles in Couette
43  flow and slightly inelastic particles in a general flowfield"
44  C Lun, S Savage, G Jeffrey, N Chepurniy
45  Journal of Fluid Mechanics
46  Volume 140, Pages 223-256, 1984
47  \endverbatim
48 
49 SourceFiles
50  Lun.C
51 
52 \*---------------------------------------------------------------------------*/
53 
54 #ifndef Lun_H
55 #define Lun_H
56 
57 #include "ParticleStressModel.H"
58 
59 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
60 
61 namespace Foam
62 {
63 namespace ParticleStressModels
64 {
65 
66 /*---------------------------------------------------------------------------*\
67  Class Lun Declaration
68 \*---------------------------------------------------------------------------*/
69 
70 class Lun
71 :
72  public ParticleStressModel
73 {
74  // Private Data
75 
76  //- Coefficient of restitution
77  scalar e_;
78 
79  //- Smallest allowable difference from the packed volume fraction
80  scalar eps_;
81 
82 
83 public:
84 
85  //- Runtime type information
86  TypeName("Lun");
87 
88 
89  //- Constructors
90 
91  //- Construct from components
92  Lun(const dictionary& dict);
93 
94  //- Construct copy
95  Lun(const Lun& hc);
96 
97  //- Clone
98  virtual autoPtr<ParticleStressModel> clone() const
99  {
101  (
102  new Lun(*this)
103  );
104  }
105 
106 
107  //- Destructor
108  virtual ~Lun();
109 
110 
111  //- Member Functions
112 
113  //- Collision stress
115  (
116  const Field<scalar>& alpha,
117  const Field<scalar>& rho,
118  const Field<scalar>& uRms
119  ) const;
120 
121  //- Collision stress derivative w.r.t. the volume fraction
123  (
124  const Field<scalar>& alpha,
125  const Field<scalar>& rho,
126  const Field<scalar>& uRms
127  ) const;
128 };
129 
130 
131 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
132 
133 } // End namespace ParticleStressModels
134 } // End namespace Foam
135 
136 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
137 
138 #endif
139 
140 // ************************************************************************* //
dictionary dict
A list of keyword definitions, which are a keyword followed by any number of values (e...
Definition: dictionary.H:158
tmp< Field< scalar > > dTaudTheta(const Field< scalar > &alpha, const Field< scalar > &rho, const Field< scalar > &uRms) const
Collision stress derivative w.r.t. the volume fraction.
Definition: Lun.C:105
Lun(const dictionary &dict)
Constructors.
Definition: Lun.C:50
Inter-particle stress model of Lun et al.
Definition: Lun.H:69
virtual autoPtr< ParticleStressModel > clone() const
Clone.
Definition: Lun.H:97
tmp< Field< scalar > > tau(const Field< scalar > &alpha, const Field< scalar > &rho, const Field< scalar > &uRms) const
Member Functions.
Definition: Lun.C:81
An auto-pointer similar to the STL auto_ptr but with automatic casting to a reference to the type and...
Definition: PtrList.H:52
volScalarField alpha(IOobject("alpha", runTime.timeName(), mesh, IOobject::READ_IF_PRESENT, IOobject::AUTO_WRITE), lambda *max(Ua &U, zeroSensitivity))
A class for managing temporary objects.
Definition: PtrList.H:53
TypeName("Lun")
Runtime type information.
virtual ~Lun()
Destructor.
Definition: Lun.C:73
Base class for inter-particle stress models.
Namespace for OpenFOAM.