Finned flat tubes geometry
The procedure:
CHX_Geom_Finned_Flat_Tube(TypeHX$: H_tube, W_tube, S_T, S_L, S, fin_pitch, fin_thk, R_T, R_L, D_h, sigma, alpha, A_fin\A)
Provides the geometric data associated with a finned flat tube compact heat exchanger surface. These data are from Kays and London (1994).
Inputs:
The only input is the string identifying the geometry TypeHX$
FF-9.68-0.87 : 'ff_tubes_s968_087'
FF-9.1-0.737-S : 'ff_tubes_s91_0737_s'
FF-9.68-0.87-R : 'ff_tubes_s968_087_r'
FF-9.29-0.737-SR : 'ff_tubes_s929_0737_sr'
FF-11.32-0.737-SR : 'ff_tubes_s1132_0737_sr'
Outputs:
H_tube = tube dimension as viewed from flow direction (m or ft)
W_tube = tube dimension as viewed perpendicular to flow direction (m or ft)
S_T = transverse tube spacing (m or ft)
S_L = longitudinal tube spacing (m or ft)
S = stagger distance (m or ft) = 0 for unstaggered geometries
fin_pitch = # fins per length (fins/m or fins/ft)
fin_thk = fin thickness (m or ft)
R_T = fin ripple amplitude in transverse direction (m or ft) = 0 for unrippled fins
R_L = fin ripple amplitude in longitudinal direction (m or ft) = 0 for unrippled fins
D_h = hydraulic diameter defined as 4 x minimum flow area x length/heat transfer area (m or ft)
sigma = minimum flow area/frontal area
alpha = heat transfer area/volume (m^2/m^3 or ft^2/ft^3)
A_fin\A = heat transfer area on fins/heat transfer area
Example
$UnitSystem SI Mass J K Pa
$VarInfo fin_pitch units=1/m
$VarInfo fin_thk units=m
$VarInfo H_tube units=m
$VarInfo R_L units=m
$VarInfo R_T units=m
$VarInfo S_L units=m
$VarInfo S_T units=m
$VarInfo S units=m
$VarInfo W_tube units=m
TypeHX$='ff_tubes_s968_087_R'
Call chx_geom_finned_flat_tube(TypeHX$: H_tube, W_tube, S_T, S_L, S, fin_pitch, fin_thk, R_T, R_L, D_h, sigma, alpha, A_fin\A)
{Solution:
H_tube = 0.00305 [m]
W_tube = 0.0221 [m]
S_T = 0.011 [m]
S_L = 0.0269 [m]
S = 0 [m]
fin_pitch = 381 [1/m]
fin_thk = 0.00010 [m]
R_T = 0.000635 [m]
R_L = 0.00635 [m]
D_h = 0.003597 [m]
sigma = 0.697
alpha = 751 [m^2/m^3]
A_fin\A = 0.795}
Related procedures include: