where the plate distance, L, and the chimney height,
H, are correlation inputs (equation 7.96 in
Ref. 40).
RaL is given by
Equation 4-158 or
Equation 4-159. The material data are evaluated at
(T + Text) ⁄ 2.
where the tube diameter, D, and the chimney height,
H, are correlation inputs (table 7.2 in
Ref. 40 with
Dh = D).
RaD is given by
Equation 4-158 or
Equation 4-159 with
L replaced by
D. The material data are evaluated at
(T + Text) ⁄ 2.