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FC_sphere_ND

 

 

The procedure FC_sphere_ND(Ra, Pr: Nusselt) returns the Nusselt number for a sphere (heated or cooled) immersed in a fluid, given a characteristic Rayleigh and Prandtl numbers. The Rayleigh number should be calculated based on the diameter, D. 

 

Inputs:

Ra - Rayleigh number based on sphere diameter, D [-]

Pr - Prandtl number of fluid [-]

 

Outputs:

Nusselt - Nusselt number [-]

 

Notes:

The procedure FC_sphere_ND is called by the dimensional variant FC_sphere to determine the Nusselt number. The procedure FC_sphere_ND is based on the Churchill (1983) correlation as described in section 6.2.3 of Nellis and Klein. This correlation is valid for Pr>~0.7 and Ra<~1e11.

 

Example:    

Ra=1.5e6

Pr=2.0

Call FC_sphere_ND(Ra, Pr: Nusselt)

 

{Solution: Nusselt=19.52}

 

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