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K_supply_main



The K_supply_main(V2overV3) function returns the resistance coefficient for a supply duct.  The coefficient returned is for the main duct and should be applied to the upstream main duct velocity.  The coefficient is a function of the downstream to upstream volumetric flow rates.  The correlation is for circular ducts.  Note that the function DuctSupplyMain_CL in the component library implements the dimensional version of this function.  

Inputs: 
V2overV3 = ratio of downstream to upstream flow rates

Example:
$UnitSystem SI C kPa Degree
$VarInfo DELTAP units=Pa
$VarInfo rho units=kg/m^3
V2overV3=0.4
K=k_supply_main(V2overV3)
vel = 10 [m/s]
P = Po#
T = 20 [C]
F$ = 'Air'
rho=density(F$,P=P,T=T)
DELTAP = rho*vel^2/2*K

{Solution:
DELTAP=5.212 [Pa]
K=0.08657
}




Reference:
Legg, R., 2017, "Chapter 14: Ducted Air Systems" in Air Conditioning System Design, Butterworth-Heinemann

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