InterviewSolution
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InterviewSolution
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Which of these is the spectral cut-off filter function?(a) \(\prod_{i=1}^3\frac{sin[(x_i-x_i^{‘})/\Delta]}{(x_i-x_i^{‘})}\)(b) \(\prod_{i=1}^3 sin[(x_i-x_i^{‘})/\Delta] \)(c) \(\prod_{i=1}^3\frac{sin[(x_i-x_i^{‘})]}{(x_i-x_i^{‘})}\)(d) \(\prod_{i=1}^3 sin[(x_i-x_i^{‘})/\Delta]\)This question was posed to me in homework.Enquiry is from Large Eddy Simulation for Turbulent Models topic in portion Turbulence Modelling of Computational Fluid Dynamics |
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Answer» CORRECT CHOICE is (a) \(\prod_{i=1}^3\frac{sin[(x_i-x_i^{‘})/\Delta]}{(x_i-x_i^{‘})}\) To explain I would SAY: The spectral cut-off filter is the PRODUCT of \(\frac{sin[(x_i-x_i^{‘})]}{(x_i-x_i^{‘})}\) for all THREE directions of the x-vector. This gives a sharp cut-off in the energy spectrum at a wavelength of Δ/π. |
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