polykin.transport.hmt¤
U_cylindrical_wall ¤
U_cylindrical_wall(
hi: float,
ho: float,
di: float,
do: float,
k: float,
Rfi: float = 0.0,
Rfo: float = 0.0,
) -> float
Calculate the overall heat transfer coefficient through a cylindrical wall with convection on both sides.
Under steady-state conditions, the overall heat transfer coefficient is given by the following expression:
where \(h\) is the heat transfer coefficient, \(R_{f}\) is the fouling factor, \(d\) is the diameter, \(k\) is the wall thermal conductivity, and the subscripts \(i\) and \(o\) indicate inner and outer surfaces, respectively.
Tip
The overall heat transfer coefficient based on the inner surface, \(U_i\), can be computed using the indentity \(U_i d_i = U_o d_o\).
PARAMETER | DESCRIPTION |
---|---|
hi
|
Heat transfer coefficient at inner surface (W/(m²·K)).
TYPE:
|
ho
|
Heat transfer coefficient at outer surface (W/(m²·K)).
TYPE:
|
di
|
Inner diameter (m).
TYPE:
|
do
|
Outer diameter (m).
TYPE:
|
k
|
Wall thermal conductivity (W/(m·K)).
TYPE:
|
Rfi
|
Fouling factor at inner surface ((m²·K)/W).
TYPE:
|
Rfo
|
Fouling factor at outer surface ((m²·K)/W).
TYPE:
|
RETURNS | DESCRIPTION |
---|---|
float
|
Overall heat transfer coefficient based on outer surface (W/(m²·K)). |
See also
U_plane_wall
: related method for a plane wall.
Examples:
Calculate the overall heat transfer coefficient for a carbon steel tube subjected to convection on both sides, with heat transfer coefficients of 2000 and 1000 W/(m²·K) for the inner and outer surfaces, respectively. The tube has inner and outer diameters of 40 mm and 50 mm. Neglect fouling effects.
>>> from polykin.transport import U_cylindrical_wall
>>> hi = 2e3 # W/(m²·K)
>>> ho = 1e3 # W/(m²·K)
>>> k = 6e2 # W/(m·K)
>>> di = 40e-3 # m
>>> do = 50e-3 # m
>>> Uo = U_cylindrical_wall(hi, ho, di, do, k)
>>> print(f"Uo={Uo:.1e} W/(m²·K)")
Uo=6.1e+02 W/(m²·K)
Source code in src/polykin/transport/hmt.py
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