anchor.diff:    double precision,allocatable::presF(:,:) !< pressure force applied on cell [N]
     double precision,allocatable::condQ(:) !< heat conduction into cell [W]
     double precision,allocatable::carrier(:,:) !< {rho,rhou,rhoH} of each cell [*]
  -  double precision,allocatable::flowRho(:) !< flow rate of rho [kg/s]
  +  double precision,allocatable::advRho(:) !< advection rate of rho [kg/s]
     double precision,allocatable::fluxRhou(:,:,:) !< flux of rhou [kg/m/s^2]
  -  double precision,allocatable::flowRhou(:,:) !< flow rate of rhou into cell [kg*m/s^2]
  +  double precision,allocatable::advRhou(:,:) !< advection rate of rhou into cell [kg*m/s^2]
     double precision,allocatable::fluxRhoH(:,:) !< flux of rhoH [J/m^2/s]
  -  double precision,allocatable::flowRhoH(:) !< flow rate of rhoH into cell [J/s]
  +  double precision,allocatable::advRhoH(:) !< advection rate of rhoH into cell [J/s]
     
     ! state at the beginning of a time step
     double precision,allocatable::rho0(:),rhou0(:,:),rhoE0(:),p0(:),u0(:,:),temp0(:),Y0(:,:)
     
     ! auxiliary variables for the PISO iteration
  -  double precision,allocatable::rho1(:),p1(:),laP1(:),presF1(:,:),temp1(:),rhou1(:,:),flowRho1(:)
  +  double precision,allocatable::rho1(:),p1(:),laP1(:),presF1(:,:),temp1(:),rhou1(:,:),advRho1(:)
     
     ! scales
     double precision,allocatable::rhoScale !< density scale [kg/m^3]
  
positive.code:     call setBC()
      call findGrad(grid,p,gradP)
      if(.not.allocated(tmpFlowRho))then
        allocate(tmpFlowRho(grid%nC))
      else if(size(tmpFlowRho)/=grid%nC)then
        deallocate(tmpFlowRho)
        allocate(tmpFlowRho(grid%nC))
      end if
      tmpFlowRho(:)=flowRho(:)
      call addRhieChow(grid,rho,p,gradP,rho,dt,tmpFlowRho)
      call findDiff(grid,p,[(1d0,i=1,grid%nC)],laP)
      forall(i=1:grid%nC)
        y(i)=p(i)-Rgas*temp(i)*(rho0(i)+dt/grid%v(i)*(tmpFlowRho(i)+dt*(laP(i)-laP1(i))))
      end forall
      pressureRHS=merge(1,0,any(ieee_is_nan(y).or.(.not.ieee_is_finite(y))))
      if(c_associated(dat))then
  
negative.code:     forall(i=1:grid%nE,j=1:DIMS)
        fluxRhou(:,j,i)=rhou(j,i)*u(:,i)
      end forall
      call findAdv(grid,rhou,fluxRhou,advRhou)
      forall(i=1:grid%nC)
        rhou(:,i)=rhou0(:,i)+dt/grid%v(i)*(advRhou(:,i)+presF(:,i)+viscF(:,i))
      end forall
      y=reshape(rhou(:,1:grid%nC),[grid%nC*DIMS])
      momentumRHS=merge(1,0,any(ieee_is_nan(y).or.(.not.ieee_is_finite(y))))
  