External_Flow_Square_ND
Procedure External_Flow_Square_ND(Re,Pr: Nusselt,C_f) returns the average Nusselt number and friction coefficient for flow past a infinitely long square-shaped rod.
Inputs:
Re - Reynold's number [-], where
where
r is the density of the fluid
m is the viscosity of the fluid
W is the height of the rod
u_f is the velocity of the flow
Pr - Prandtl number [-], where
where
c_p is the specific heat capacity of the fluid
k is the conductivity
Outputs:
Nusselt - average Nusselt number assuming a constant surface temperature[-]. The Nusselt number is defined:
where
h_bar is the average heat transfer coefficient
C_d - average drag coefficient [-]. The friction coefficient is defined in terms of the drag force (F):
Notes
The correlation for Nusselt number is valid for 5E3<Re<1E5. The correlation for the drag coefficient is valid for Re>1E4
The Reynolds and Prandtl numbers are based on fluid properties evaluated at the film temperature, which is the average of the free stream and the surface temperatures.
References:
Jakob (1949) , White (2003) and Nellis and Klein
Example
call External_Flow_Square_ND(Re,Pr: Nusselt,C_d)
Re=10000 [-]
Pr=0.7 [-]
{Solution: Nusselt=45.39 [-], C_D=2.1}