External_Flow_Hexagon1_ND
Procedure External_Flow_Hexagon1_ND(Re,Pr: Nusselt,C_f) returns the average Nusselt number and friction coefficient for flow past a infinitely long hexagon-shaped rod with the flat-edge perpendicular to the flow, as shown.
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 as described in Table 4-7 of Nellis and Klein. The correlation for the drag coefficient is valid for Re>1E4.
The Reynolds and Prandtl number. are based on fluid properties evaluated at the film temperature, which is the average of the free stream and the surface temperatures.
References:
Example
call External_Flow_Hexagon1_ND(Re,Pr: Nusselt,C_d)
Re=10000 [-]
Pr=0.7 [-]
{Solution: Nusselt=66.76 [-], C_d=0.7}