1,445 research outputs found
Inspection report: Plymouth College of Further Education
Dates of inspection: 23 February–4 March 200
Optimal low-dispersion low-dissipation LBM schemes for computational aeroacoustics
Lattice Boltmzmann Methods (LBM) have been proved to be very effective
methods for computational aeroacoustics (CAA), which have been used to capture
the dynamics of weak acoustic fluctuations. In this paper, we propose a
strategy to reduce the dispersive and disspative errors of the two-dimensional
(2D) multi-relaxation-time lattice Boltzmann method (MRT-LBM). By presenting an
effective algorithm, we obtain a uniform form of the linearized Navier-Stokes
equations corresponding to the MRT-LBM in wave-number space. Using the matrix
perturbation theory and the equivalent modified equation approach for finite
difference methods, we propose a class of minimization problems to optimize the
free-parameters in the MRT-LBM. We obtain this way a
dispersion-relation-preserving LBM (DRP-LBM) to circumvent the minimized
dispersion error of the MRT-LBM. The dissipation relation precision is also
improved.And the stability of the MRT-LBM with the small bulk viscosity is
guaranteed. Von Neuman analysis of the linearized MRT-LBM is performed to
validate the optimized dispersion/dissipation relations considering
monochromatic wave solutions. Meanwhile, dispersion and dissipation errors of
the optimized MRT-LBM are quantitatively compared with the original MRT-LBM .
Finally, some numerical simulations are carried out to assess the new optimized
MRT-LBM schemes.Comment: 33 page
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