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Cond_Horizontal_Down



Procedure Cond_horizontal_down(Fluid$, T_w, T_sat: h_m, Nusselt_m) calculates the heat transfer coefficient and Nusselt number for condensation on a horizontal flat plate with the cooled side facing downward.

Inputs:
Fluid$  -  string variable representing a fluid/vapor in the EES data base.
T_w  -  the temperature of the plate in [C], [K], [F], or [R].  
T_sat  -  the saturation temperature of the bulk vapor in  [C], [K], [F], or [R].  

Outputs:
h_m  -   the mean heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R]
Nusselt_m  -  the mean Nusselt number [-]

Notes:
This procedure is responsible for determining the property data of the fluid specified. The latent heat of evaporation is modified based on the correction term developed by Rohsenow (1956). This correction term accounts for the nonlinearity of the temperature profile due to convection effects. The function Cond_Horizontal_Down uses the correlation developed by Gerstmann and Griffith (1967) as presented in Nellis and Klein. This correlation is based on the condensate being removed as droplets, which formed due to Taylor instability on the condensate surface.

Example:
$UnitSystem SI C Pa J
$VarInfo h_m units=W/m^2-K
Fluid$='water'
T_w=50 [C]
T_sat=100 [C]
Call cond_horizontal_down(Fluid$, T_w, T_sat: h_m, Nusselt_m)

{Solution: 
h_m=5577 [W/m^2-K]     
Nusselt_m=21.68}


Condensation Index