c-------------------------------------------------------------------------------
c ... set reference dimensional quantities and other universal constants

	subroutine ref_gen(r0,patm,boltzk,avogadro,tempref,cpref,href,
     1                     pref,wref,rgref,rhoref,wspref,capdref,
     2                     htcndref,caplref,velref,vdiffref,amuref,
     3                     tymref,cref,cgref,gref,damkohlr)

	IMPLICIT NONE

	double precision r0,patm,boltzk,avogadro,tempref,cpref,href,pref,
     1                   wref,rgref,rhoref,wspref,capdref,htcndref, 
     2          	 caplref,velref,vdiffref,amuref,tymref,cref,
     3                   cgref,gref,damkohlr


c-------------------------------------------------------------------------------

	r0      = 8314.51      	! univ gas const J/kg-mol.K
	patm    = 101325.0	! atmospheric pressure N/m^2
	boltzk  = 1.3805e-23 	! Boltzmann's constant (units: J/K)
	avogadro= 6.0225e26 	! Avogadro's number (1/kg-mol)

c-------------------------------------------------------------------------------
	tempref = 300.0		! Ref temperature (K)
	cpref   = 1000.0	! Ref cp (J/kg.K)		
	href    = cpref*tempref ! Ref enthalpy (J/kg)
	pref    = patm		! Ref pressure (N/m^2)
	wref    = 28.0          ! Ref molar (or molar) weight (kg/kg-mol)
	rgref   = r0/wref       ! Ref gas constant (J/kg.K)
	rhoref  = pref/(rgref*tempref)		! Ref density (kg/m^3)
	wspref  = 500.0         ! Ref reaction rate (kg/m^3.s) (arbitrary)
	capdref = 0.88e-4       ! Ref mass diffusion coeff (m^2/s) (arb)
	htcndref= 0.1           ! Ref thermal conductivity (J/mKs) (arb)
	caplref = 1.e-2		! Ref length (m) (arb)
	velref  = 5.0           ! Ref velocity (m/s) (arb)
	vdiffref= capdref/caplref ! Ref diffusion velocity (m/s) 
	amuref  = 7.0e-5	! Ref dynamic viscosity (kg/m.s) (arb)
	tymref  = caplref/velref ! Ref time, (sec)
	cref    = rhoref/wref   ! Ref concentration (kg-mol/m^3)
	cgref   = r0*tempref    ! Ref Gibbs free energy, molar (J/kg-mol)
	gref    = cgref/wref    ! Ref Gibbs free energy, mass_units (J/kg)
	damkohlr = caplref*wspref/(rhoref*velref) ! Damkohlr number

	return
	end