Ignore:
Timestamp:
Jan 22, 2018 11:34:58 AM (4 years ago)
Author:
maronga
Message:

major bugfix in calculation of aerodynamic resistance for vertical surface elements

File:
1 edited

Legend:

Unmodified
Added
Removed
  • palm/trunk/SOURCE/land_surface_model_mod.f90

    r2735 r2765  
    2525! -----------------
    2626! $Id$
     27! Major bugfix in calculation of f_shf for vertical surfaces
     28!
     29! 2735 2018-01-11 12:01:27Z suehring
    2730! output of r_a moved from land-surface to consider also urban-type surfaces
    2831!
     
    17701773!        ENDIF
    17711774!
    1772 !--    Calculate aerodynamical resistance. For horizontal and vertical
    1773 !--    surfaces MOST is applied. Moreover, for vertical surfaces, resistance
    1774 !--    can be obtain via parameterization of Mason (2000) /
    1775 !--    Krayenhoff and Voogt (2006).
     1775!--     Calculation of r_a for vertical surfaces
     1776!--
     1777!--     heat transfer coefficient for forced convection along vertical walls
     1778!--     follows formulation in TUF3d model (Krayenhoff & Voogt, 2006)
     1779!--           
     1780!--       H = httc (Tsfc - Tair)
     1781!--       httc = rw * (11.8 + 4.2 * Ueff) - 4.0
     1782!--           
     1783!--             rw: wall patch roughness relative to 1.0 for concrete
     1784!--             Ueff: effective wind speed
     1785!--             - 4.0 is a reduction of Rowley et al (1930) formulation based on
     1786!--             Cole and Sturrock (1977)
     1787!--           
     1788!--             Ucan: Canyon wind speed
     1789!--             wstar: convective velocity
     1790!--             Qs: surface heat flux
     1791!--             zH: height of the convective layer
     1792!--             wstar = (g/Tcan*Qs*zH)**(1./3.)
     1793               
     1794!--    Effective velocity components must always
     1795!--    be defined at scalar grid point. The wall normal component is
     1796!--    obtained by simple linear interpolation. ( An alternative would
     1797!--    be an logarithmic interpolation. )
     1798!--    A roughness lenght of 0.001 is assumed for concrete (the inverse,
     1799!--    1000 is used in the nominator for scaling)
    17761800!--    To do: detailed investigation which approach gives more reliable results!
    17771801!--    Please note, in case of very small friction velocity, e.g. in little
     
    17821806                             ( surf%ts(m) * surf%us(m) + 1.0E-20_wp ) )
    17831807       ELSE
    1784           surf%r_a(m) = 1.0_wp / ( 11.8_wp + 4.2_wp *                          &
     1808          surf%r_a(m) = rho_cp / ( surf%z0(m) * 1000.0_wp                      &
     1809                        * ( 11.8_wp + 4.2_wp *                                 &
    17851810                        SQRT( MAX( ( ( u(k,j,i) + u(k,j,i+1) ) * 0.5_wp )**2 + &
    17861811                                   ( ( v(k,j,i) + v(k,j+1,i) ) * 0.5_wp )**2 + &
    17871812                                   ( ( w(k,j,i) + w(k-1,j,i) ) * 0.5_wp )**2,  &
    17881813                              0.01_wp ) )                                      &
    1789                                  )
     1814                           )  - 4.0_wp  )
    17901815       ENDIF
    17911816!
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