From CFD-Wiki
!Sample program for solving Lid-driven cavity flow test using SIMPLE-algorithm
! covective terms approximation - HLPA scheme implementation modul
!Copyright (C) 2010 Michail Kiričkov
!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.
!**********************************************************************
! HLPA scheme
Subroutine HLPA(Uw,Fww,Fw,Fp,Fe,Delta_f)
If (Uw.GE.0.) then
if ( ABS( Fp - 2.* Fw + Fww ).LT.ABS( Fp - Fww ) ) then
Alpha_pl = 1.
else
Alpha_pl = 0.
End If
If ( (Fp - Fww).NE.0. ) then
Delta_f = Alpha_pl * (Fp - Fw)* (Fw - Fww) / (Fp - Fww)
End If
End If
!-------------------------------------------------------------------------
If (Uw.LT.0.) then
if ( ABS( Fw - 2.* Fp + Fe ).LT.ABS( Fw - Fe ) ) then
Alpha_mn = 1.
else
Alpha_mn = 0.
End If
If ( (Fw - Fe).NE.0. ) then
Delta_f = Alpha_mn * (Fw - Fp)* (Fp - Fe) / (Fw - Fe)
End If
End If
100 continue
Return
End