Exernal_Flow_Cuboid
Procedure External_Flow_Cuboid(Fluid$, T_inf, T_s, P, u_inf, a, b, c: F_d, h) calculates the average heat transfer coefficient and drag force for external flow past a cuboid. The drag coefficient correlation is obtained from Haider and Levenspiel (1989) while the Nusselt number correlation is obtained from Yovanovich (1988). Propeties are evaluated at the film temperature. The units of the inputs and outputs of the procedure depend on the units setting in EES.
Inputs
Fluid$ is a string or string variable that can be any fluid in the EES data base. The fluid can be an ideal gas, a real fluid, a brine, or an incompressible fluid in the Solid-Liquid_Props fluids library.
T_inf - the free stream fluid temperature in [C], [K], [F], or [R].
T_s - the surface temperature of the sphere in [C], [K], [F], or [R].
P - pressure can be in [Pa], [kPa], [bar], [MPa], [atm] or [psia]. (Note that for brines, this parameter provides the concentration in % instead of pressure.)
u_inf - free stream velocity of the flow in [m/s] or [ft/min]
a and b - dimensions of the cuboid perpendicular to the flow, in [m] or [ft]
c - dimension of the cuboid in the flow direction, in [m] or [ft]
Outputs
F_d - drag force [N] or [lbf]
h - average heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R]
Example:
$UnitSystem SI Pa J K m
$VarInfo F_d units=N
$VarInfo h units=W/m^2-K
T_inf=300 [K]
T_s=350 [K]
P=101325 [Pa]
Fluid$='Air'
u_inf=20 [m/s]
a=0.2 [m]
b=0.2 [m]
c=0.2 [m]
Call external_flow_cuboid(Fluid$,T_inf,T_s,P,u_inf,a,b,c:F_d,h)
{Solution:
F_d=11.92 [N]
h=38.21 [W/m^2-K]
}