centralWithAntidiffusivity.hh

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/*  This file is part of the OpenLB library
 *
 *  Copyright (C) 2020 Davide Dapelo
 *  E-mail contact: info@openlb.net
 *  The most recent release of OpenLB can be downloaded at
 *  <http://www.openlb.net/>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA  02110-1301, USA.
*/
 
#ifndef FD_SCHEMES_CENTRAL_WITH_ANTIDIFFUSIVITY_HH
#define FD_SCHEMES_CENTRAL_WITH_ANTIDIFFUSIVITY_HH
 
namespace olb {
 
namespace fd {
 
template <unsigned D, typename T>
template <typename PARAMETERS>
T DiffusionScheme<D,T,tag::CENTRAL_WITH_ANTIDIFFUSIVITY>::
apply(T& f0, T f[], T F[], T u[], PARAMETERS& params)
{
  T fNew  = 0.;
  T fCorr = 0.; // Negative-diffusivity correction to counterbalance upwind schemes' numerical diffusivity
  for (unsigned iD=0; iD<D; ++iD) {
    fNew  +=  F[getArrayPos<1>(0,iD)] + f[getArrayPos<1>(0,iD)];
    fCorr += (F[getArrayPos<1>(0,iD)] + f[getArrayPos<1>(0,iD)] - 2.*f0) * abs(u[iD]);
  }
  fNew -= 2.*D*f0;
  return fNew * params.template get<fdParams::Diffusivity>()
         - 0.5 * fCorr * params.template get<fdParams::AntiDiffusivityTuning>();
}
 
}  // namespace fd
 
}  // namespace olb
 
#endif