anchor.diff:    
     ! data for algebraic solver
     type(NewtonKrylov)::pbcEq !< momentum and pressure equations (isothermal) solved by Newton-GMRES
  +  type(ILU)::pbcPrec !< PBC preconditioner
     type(fixPt)::energyEq !< energy equation as a fix point problem
     type(NewtonKrylov)::fullEq !< full NS equations solved by Newton-GMRES
     integer::nItPBC,nItEnergy,nItOuter,nItFull !< number of iterations
  
positive.code:   integer,parameter::MAXIT_ENERGY=50 !< max number of energy equation iterations
    integer,parameter::MAXIT_OUTER=20 !< max number of outer iterations
    integer,parameter::MAXIT_FULL=50 !< max number of full NS equation iterations
    
    integer,parameter::BC_WALL_TEMP=1 !< wall boundary with prescribed temperature
    integer,parameter::BC_WALL_TEMP_UDF=101 !< wall boundary with prescribed temperature by UDF
  
negative.code:   
    double precision,allocatable::massFlowSensU(:,:,:) !< sensitivity of mass flow rate on velocity
    double precision,allocatable::massFlowSensP(:,:) !< sensitivity of mass flow rate on pressure
    integer,allocatable::pbcPrecI(:),pbcPrecJ(:) !< PBC preconditioner COO index
    double precision,allocatable::pbcPrecVal(:) !< PBC preconditioner COO value
    
    ! scales and scaling factors
    double precision,allocatable::rhoScale !< density scale [kg/m^3]
  