48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
/*======================================================================*/
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// This routine evaluates q(k) (McComb, p61) by summing all wavevectors
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// in a k-shell. Then we divide through by the volume of the box
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// - to be accurate, by the volume of the ellipsoid enclosing the
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// box (assume cells even in each direction). Finally, multiply the
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// q(k) values by k^2 to give the full power spectrum E(k). Integrating
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// this over the whole range gives the energy in turbulence.
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/*======================================================================*/
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#include "calcEk.H"
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#include "fft.H"
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#include "Kmesh.H"
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#include "kShellIntegration.H"
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#include "volFields.H"
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#include "graph.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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namespace Foam
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{
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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graph calcEk
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(
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const volVectorField& U,
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const Kmesh& K
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)
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{
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return kShellIntegration
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(
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fft::forwardTransform
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(
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ReComplexField(U.internalField()),
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K.nn()
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),
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K
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);
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}
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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} // End namespace Foam
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// ************************************************************************* //
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