FC_Tilted_rect_enclosure
Procedure FC_Tilted_Rect_Enclosure(Fluid$, T_h, T_c, P, L, delta, tau : h, Nusselt, Ra) returns the heat transfer coefficient in a rectangular channel that is tilted with respect to horizontal at a specified angle, tau. The units of the inputs and outputs depend on the unit settings in EES.
Inputs:
Fluid$ can be any fluid in the EES data base. The fluid can be an ideal gas or a real fluid.
T_h - temperature of the lower surface (assumed warmer) in [C], [K], [F], or [R].
T_c - temperature of the upper surface (assumed cooler) in [C], [K], [F], or [R].
P - pressure can be in [Pa], [kPa], [bar], [MPa], [atm], or [psia].
L - length of the channel in [m] or [ft]
delta - gap between the lower and upper surfaces in [m] or [ft]
tau - angle relative to horizontal in [rad] or [deg]
Outputs:
h - heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R]
Nusselt - Nusselt number [-]
Ra - Raleigh number based on delta [-]
Notes:
The correlation is from Hollands, G.K, T., Unny, T.E., Raithby, G.D, and Konicek, L., "Free Convection Heat Transfer Across Inclined Air Layers," Trans. ASME J. of Heat Transfer, Vol. 98, No. 189, (1976). For angles >70 deg, the correlation is modified according to Catton, Proc. 6th Int. Heat Transfer Conf., 1978, Vol. 6, pp.13-31 and Arnold, Catton and Edwards, ASME Paper 75-HT-62, 1975 as described in section 6.2.6 of Nellis and Klein.
The procedure can also be called with name Tilted_Rect_Enclosure for backward compatibility reasons.
The ratio of the channel width to delta is assumed to be > 12. Also, L/delta should be >12 for the correlation to be applicable.
This function calls its non-dimensional equivalent FC_Tilted_rect_enclosure_ND to do the calculations.
Example:
$UnitSystem SI deg C J Pa
$VarInfo h units=W/m^2-K
delta=0.025 [m]
P=101300 [Pa]
T_h=45 [C]
T_c=30 [C]
L=10 [m]
tau = 45 [deg]
Fluid$='Air'
Call fc_tilted_rect_enclosure(Fluid$, T_h, T_c, P, L, delta, tau : h, Nusselt, Ra#)
{Solution:
h=2.562 [W/m^2-K
Nusselt=2.423
Ra#=19,046}
Starting with version 9.513, it is not necessary to evaluate all of the outputs. For example, if you only wish to return variable h, you can enter:
Call FC_Tilted_Rect_Enclosure(Fluid$, T_h, T_c, P, L, delta, tau : h, , )
The list separator is a comma for the US system shown here and a semicolon for the European system.