FreeFOAM The Cross-Platform CFD Toolkit
turbGen.C
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25 
26 #include <randomProcesses/fft.H>
27 #include "turbGen.H"
28 #include <randomProcesses/Kmesh.H>
30 #include "Ek.H"
32 
33 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
34 
35 namespace Foam
36 {
37 
38 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
39 
40 // from components
41 turbGen::turbGen(const Kmesh& k, const scalar EA, const scalar K0)
42 :
43  K(k),
44  Ea(EA),
45  k0(K0),
46  RanGen(label(0))
47 {}
48 
49 
50 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
51 
52 // generate and return a velocity field
54 {
55  scalar pi2=2*mathematicalConstant::pi;
56 
57  vectorField s(K.size());
58  scalarField rndPhases(K.size());
59 
60  forAll(K, i)
61  {
62  s[i] = RanGen.vector01();
63  rndPhases[i] = RanGen.scalar01();
64  }
65 
66  s = K ^ s;
67  s = s/(mag(s) + 1.0e-20);
68 
69  s = Ek(Ea, k0, mag(K))*s;
70 
72  (
73  ComplexField(cos(pi2*rndPhases)*s, sin(pi2*rndPhases)*s),
74  K.nn()
75  );
76 
77  return ReImSum(up);
78 }
79 
80 
81 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
82 
83 } // End namespace Foam
84 
85 // ************************ vim: set sw=4 sts=4 et: ************************ //
86