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FC_plate_vertical_ND

 

 

The procedure FC_plate_vertical_ND(Ra, Pr: Nusselt) returns the Nusselt number for a vertical flat plate (heated or cooled) given the Rayleigh and Prandtl numbers. The Rayleigh number should be calculated based on the length L in the direction of gravity. 

 

The width of the plate is assumed sufficiently large such that end effects may be neglected.  

 

Inputs:

Ra - Rayleigh number based on plate length L [-]

where 

Ra = g*L^3*beta*DT/(nu*alpha)

g = gravity

L = plate length (in the direction of gravity)

beta = volumetric thermal expansion coefficient

DT = magnitude of the temperature difference

nu = kinematic viscosity

alpha = thermal diffusivity

 

Pr - Prandtl number of fluid [-]

 

Outputs:

Nusselt - average Nusselt number based on plate length [-]

where 

Nusselt = h_bar*L/k

h_bar = average heat transfer coefficient

k = conductivity

 

Notes:

The correlation in procedure FC_plate_vertical_ND is from Churchill and Chu (1975b).

 

The correlation is valid from 0.1<Ra<1e12.

 

Example:    

Ra=1.5e6

Pr=0.7

Call FC_plate_vertical_ND(Ra, Pr: Nusselt)

 

{Solution: Nusselt=18.42} 

 

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