!
!*** Jan Mandel August-October 2007 email: jmandel@ucar.edu or Jan.Mandel@gmail.com
!
! This file contains parts copied and/or adapted from earlier codes by
! Terry Clark, Janice Coen, Don Latham, and Net Patton.
module module_fr_sfire_phys 
(docs) 3
use module_model_constants
, only: cp,xlv
use module_fr_sfire_util
! Following table copied from module_fr_cawfe_fuel by Ned Patton with minor changes.
! Based on: Clark, T. L., J. L. Coen and D. Latham: 2004,
! "Description of a coupled atmosphere-fire model",
! International Journal of Wildland Fire, 13, 49-63.
!
! edited by Jan Mandel jmandel@ucar.edu September 2007
!
! - moved all fuel related constants and the initialization subroutine here
! - copied descriptions for fuel categories from fire_sfc.m4 in the original CAWFE code
! This file had to be copied under a new name because packages in wrf physics
! layer are not allowed to call each other.
!D in col 2 means quantity derived from the others
!
! Scalar constants (data same for all fuel categories):
! HFGL SURFACE FIRE HEAT FLUX THRESHOLD TO IGNITE CANOPY (W/m^2)
! CMBCNST JOULES PER KG OF DRY FUEL
! FUELHEAT FUEL PARTICLE LOW HEAT CONTENT, BTU/LB
! FUELMC_G FUEL PARTICLE (SURFACE) MOISTURE CONTENT
!D BMST RATIO OF LATENT TO SENSIBLE HEAT FROM SFC BURN:
! % of total fuel mass that is water (not quite
! = % fuel moisture). BMST= (H20)/(H20+DRY)
! so BMST = FUELMC_G / (1 + FUELMC_G) where
! FUELMC_G = ground fuel moisture
!
! Data arrays indexed by fuel category:
! FGI INITIAL TOTAL MASS OF SURFACE FUEL (KG/M**2)
! FUELDEPTHM FUEL DEPTH, IN M (CONVERTED TO FT)
! SAVR FUEL PARTICLE SURFACE-AREA-TO-VOLUME RATIO, 1/FT
! GRASS: 3500., 10 hr fuel: 109., 100 hr fuel: 30.
! FUELMCE MOISTURE CONTENT OF EXTINCTION; 0.30 FOR MANY DEAD FUELS; 0.15 FOR GRASS
! FUELDENS OVENDRY PARTICLE DENSITY, LB/FT^3
! ST FUEL PARTICLE TOTAL MINERAL CONTENT
! SE FUEL PARTICLE EFFECTIVE MINERAL CONTENT
! WEIGHT WEIGHTING PARAMETER THAT DETERMINES THE SLOPE OF THE MASS LOSS CURVE
! RANGES FROM ~5 (FAST BURNUP) TO 1000 ( ~40% DECR OVER 10 MIN).
! FCI_D INITIAL DRY MASS OF CANOPY FUEL
! FCT BURN OUT TIME FOR CANOPY FUEL, AFTER DRY (S)
! ichap 1 if chaparral, 0 if not
!D FCI INITIAL TOTAL MASS OF CANOPY FUEL
!D FCBR FUEL CANOPY BURN RATE (KG/M**2/S)
! =============================================================================
! Standard 13 fire behavior fuel models (for surface fires), along with some
! estimated canopy properties (for crown fire).
! =============================================================================
! FUEL MODEL 1: Short grass (1 ft)
! FUEL MODEL 2: Timber (grass and understory)
! FUEL MODEL 3: Tall grass (2.5 ft)
! FUEL MODEL 4: Chaparral (6 ft)
! FUEL MODEL 5: Brush (2 ft)
! FUEL MODEL 6: Dormant brush, hardwood slash
! FUEL MODEL 7: Southern rough
! FUEL MODEL 8: Closed timber litter
! FUEL MODEL 9: Hardwood litter
! FUEL MODEL 10: Timber (litter + understory)
! FUEL MODEL 11: Light logging slash
! FUEL MODEL 12: Medium logging slash
! FUEL MODEL 13: Heavy logging slash
! FUEL MODEL 14: no fuel??
!
REAL, PARAMETER :: cmbcnst = 17.433e+06 ! J/kg dry fuel
REAL, PARAMETER :: hfgl = 17.e4 ! W/m^2
REAL, PARAMETER :: fuelheat = cmbcnst * 4.30e-04 ! convert J/kg to BTU/lb
REAL, PARAMETER :: fuelmc_g = 0.08 ! set = 0 for dry ground fuel
REAL, PARAMETER :: fuelmc_c = 1.00 ! set = 0 for dry canopy
REAL, PARAMETER :: bmst = fuelmc_g/(1+fuelmc_g)
!real, parameter :: xlv = 2.5e6 ! to make it selfcontained
!real, parameter :: cp = 7.*287./2 ! to make it selfcontained
INTEGER, PARAMETER :: nfuelcats = 14
INTEGER, DIMENSION( nfuelcats ), save :: ichap
REAL , DIMENSION( nfuelcats ), save :: weight,fgi,fci,fci_d,fct,fcbr, &
fueldepthm,fueldens,fuelmce, &
savr,st,se
DATA fgi / 0.166, 0.897, 0.675, 2.468, 0.785, 1.345, 1.092, &
1.121, 0.780, 2.694, 2.582, 7.749, 13.024, 1.e-7 /
DATA fueldepthm /0.305, 0.305, 0.762, 1.829, 0.61, 0.762,0.762, &
0.0610, 0.0610, 0.305, 0.305, 0.701, 0.914, 0.305 /
DATA savr / 3500., 2784., 1500., 1739., 1683., 1564., 1562., &
1889., 2484., 1764., 1182., 1145., 1159., 3500. /
DATA fuelmce / 0.12, 0.15, 0.25, 0.20, 0.20, 0.25, 0.40, &
0.30, 0.25, 0.25, 0.15, 0.20, 0.25, 0.12 /
DATA fueldens / nfuelcats * 32. / ! 32 if solid, 19 if rotten.
DATA st / nfuelcats* 0.0555 /
DATA se / nfuelcats* 0.010 /
! ----- Notes on weight: (4) - best fit of Latham data;
! (5)-(7) could be 60-120; (8)-(10) could be 300-1600;
! (11)-(13) could be 300-1600
DATA weight / 7., 7., 7., 180., 100., 100., 100., &
900., 900., 900., 900., 900., 900., 7. /
! ----- 1.12083 is 5 tons/acre. 5-50 tons/acre orig., 100-300 after blowdown
DATA fci_d / 0., 0., 0., 1.123, 0., 0., 0., &
1.121, 1.121, 1.121, 1.121, 1.121, 1.121, 0./
DATA fct / 60., 60., 60., 60., 60., 60., 60., &
60., 120., 180., 180., 180., 180. , 60. /
DATA ichap / 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 /
! =========================================================================
contains
subroutine init_fuel_cats (docs)
implicit none
!*** purpose: initialize fuel tables by constants
!*** arguments: none
!*** local
integer:: nf
end subroutine init_fuel_cats
end module module_fr_sfire_phys