PF wavy-fin ND functions
The procedure:
CHX_ND_PF_wavy_fin(TypeHX$, Re: f, j_H)
provides the dimensionless performance associated with a plain fin - wavy fin compact heat exchanger surface. These data are from Kays and London (1994).
Inputs
TypeHX$: string identifying the geometry
11.44-3/8W: 'PF_wavy-fin_1144_38W'
11.5-3/8W: 'PF_wavy-fin_115_38W'
17.8-3/8W: 'PF_wavy-fin_178_38W'
Re: Reynolds number (-)
Outputs
f: friction factor (-)
j_H: Colburn j function for heat transfer (-)
The Reynolds number is defined according to:
where m is the viscosity, Dh is the hydraulic diameter, and G is the mass flux. The hydraulic diameter is defined as:
where Ac is the minimum free flow area, A is the total heat transfer area, and L is the length in the flow direction.
The mass flux is defined as:
where 
The friction factor is defined as:
where r is the density, and to is the equivalent shear stress, defined as:
where DP is the pressure drop due to friction and form drag in the core.
Example
$UnitSystem SI Mass J K Pa
TypeHX$= 'PF_wavy-fin_115_38W'
Re=1000
Call chx_nd_pf_wavy_fin(TypeHX$, Re: f, j_H)
{Solution is:
f = 0.08316, j_H = 0.01577}
Related procedures include: