ZigZag_local
Procedure ZigZag_local(Fluid$, T, P, m_dot, R_c, alpha: h, dPdx, Nusselt, f, Re) returns the local (averaged over a unit cell) heat transfer coefficient and pressure gradient associated with flow through a zig-zag channel. The procedure also provides the local Nusselt number, local friction factor, and Reynolds number (entrance effects are not included - these are local in that they are at a particular location)
Inputs:
Fluid$ can be any fluid in the EES database. The fluid can be an ideal gas or a real fluid.
T - the bulk temperature of the fluid in [C], [K], [F], or [R].
P - pressure in [Pa], [kPa], [bar], [MPa], [atm], or [psia].
m_dot - mass flow rate in [kg/s], or [lbm/hr]
R_c - channel radius [m] or [ft]
alpha - angle [degree] or [radian]
Outputs:
h - local heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R]
dPdx - local pressure gradient. [(Pa, kPa, bar, or atm)/m] or [(psi or atm)/ft] depending on EES pressure unit setting
Nusselt - local Nusselt number
f - local friction factor
Re - Reynolds number based on properties evaluated at the bulk average temperature
Notes:
This procedure calls ZigZag_ND_local to obtain the Nusselt numbers and friction factor using the correlation from Moisseytsev et al. (2020)
Example:
$UnitSystem SI Mass J K Pa Radian
$VarInfo dPdx units=Pa/m
$VarInfo h units=W/m^2-K
alpha=50 [degree]*convert(degree,rad)
Fluid$='CarbonDioxide'
T=750 [K]
P=10e6 [Pa]
R_c=2 [mm]*convert(mm,m)
m_dot=0.001 [kg/s]
Call zigzag_local(Fluid$, T, P, m_dot, R_c, alpha: h, dPdx, Nusselt, f, Re)
{Solution:
h = 1056 [W/m^2-K]
dPdx = 6243 [Pa/m]
Nusselt = 46.81
f = 0.08435
Re = 11425
}