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Film_Boiling

 

 

The function Film_Boiling(Fluid$, Geom$, T_sat, T_s, D, epsilon) returns the surface heat flux for film boiling of a fluid by means of a heated horizontal cylindrical or spherical surface

 

Inputs

Fluid$ - string constant or variable representing a fluid/vapor in the EES data base.

Geom$ -string constant or variable that contains either 'SPHERE' or 'CYLINDER'  (case insensitive)

T_sat - the saturation temperature of the boiling liquid in  [C], [K], [F], or [R].  

T_s - the temperature of the heated surface  in [C], [K], [F], or [R].  

D - the diameter of the sphere or horizontal cylinder in [m] or [ft]

epsilon - the emittance of the surface

 

Output

The surface heat flux due to film boiling in [W/m^2] or [Btu/hr-ft^2]

 

Notes:

This procedure is responsible for determining the property data of the specified fluid . It uses the correlation developed by Bromley (1950) as reported in Incropera and DeWitt (2002).  The heat transfer coefficient associated with the surface heat flux that is calculated includes contributions from convection and radiation weighted such that:

 

 

where h_bar_conv is the heat transfer coefficient resulting from convection and h_bar_rad is the heat transfer coefficient resulting from radiation.

 

Example:

$unitSystem SI K bar

epsilon=0.05

D=5 [mm]*convert(mm,m)

T_s=convertTemp(C,K,350 [C])

T_sat=convertTemp(C,K,100 [C])

q``_s=Film_Boiling('Water','Cylinder',T_sat,T_s,D, epsilon)

 

{Solution:    q``_s=59674 [W/m^2]}

 

 

Boilling Index